JP5623657B2 - Cryptographic communication system, cryptographic processing apparatus, computer program, and cryptographic communication method - Google Patents

Description

  The present invention relates to a cryptographic communication system in which a plurality of devices perform cryptographic communication.

When communication is performed using a communication method that can be easily wiretapped, such as Internet communication or wireless communication, encryption communication is used to prevent wiretapping or tampering by a third party.
For example, when performing encrypted communication using common key encryption, it is necessary to share a key used between a transmission side and a reception side, and it is necessary to prevent the shared key from leaking to the outside.

JP 2010-68396 A JP 2001-251292 A JP 2002-290391 A

For example, if a small and portable device, such as a portable terminal used in an automatic meter reading system, has a key, the user can lose the device and a third party can pick it up and the key can leak. There is sex.
An object of the present invention is to make it easy to share and change a key used for encrypted communication, for example.

An encryption communication system according to the present invention includes:
In a cryptographic communication system comprising a management device, a first cryptographic communication device, and a second cryptographic communication device,
The management device includes a master key storage unit and a temporary key generation unit,
The master key storage unit of the management device stores a first master key,
The temporary key generation unit of the management device generates a first temporary key using the first master key stored in the master key storage unit of the management device and the temporary key generation data,
The first encryption communication device includes a temporary key generation data notification unit and an encryption communication unit,
The temporary key generation data notifying unit of the first encryption communication device is configured to transfer the temporary key generation data used by the temporary key generation unit of the management device to generate the first temporary key to the second encryption Notify the communication device,
The cryptographic communication unit of the first cryptographic communication device performs cryptographic communication with the second cryptographic communication device using the first temporary key generated by the temporary key generation unit of the management device,
The second cryptographic communication device includes a master key storage unit, a temporary key generation data verification unit, a temporary key generation unit, and an encryption communication unit,
The master key storage unit of the second encryption communication device is the same as the first master key stored in the master key storage unit of the management device or corresponds to the first master key. Remember
The temporary key generation data verification unit of the second encryption communication device determines whether the temporary key generation data notified from the temporary key generation data notification unit of the first encryption communication device is valid. Judgment,
When the temporary key generation data notified from the temporary key generation data notifying unit of the first cryptographic communication device is valid, the temporary key generation unit of the second cryptographic communication device is valid. When the temporary key generation data verification unit determines, the second master key stored in the master key storage unit of the second encryption communication device and the temporary key generation data of the second encryption communication device The first temporary key that is the same as the first temporary key generated by the temporary key generation unit of the management device using the temporary key generation data determined to be valid by the verification unit or the first temporary key Generate a second temporary key corresponding to
The cryptographic communication unit of the second cryptographic communication device uses the second temporary key generated by the temporary key generation unit of the second cryptographic communication device to perform cryptographic communication with the first cryptographic communication device. It is characterized by doing.

  Since the second cryptographic communication apparatus generates a temporary key using the temporary key generation data notified from the first cryptographic communication apparatus, the first cryptographic communication apparatus and the second cryptographic communication apparatus are the same or correspond to each other. You can use the temporary key for encrypted communication. This makes it easy to share or change the temporary key.

1 is a system configuration diagram illustrating an example of an overall configuration of a cryptographic communication system 800 according to Embodiment 1. FIG. 2 is a hardware configuration diagram illustrating an example of hardware resources of a management apparatus 100, an encryption communication apparatus 200, and an encryption communication apparatus 300 in Embodiment 1. FIG. FIG. 3 is a block configuration diagram illustrating an example of functional blocks of the management apparatus 100 according to the first embodiment. FIG. 3 is a block configuration diagram illustrating an example of functional blocks of the cryptographic communication device 200 according to the first embodiment. FIG. 3 is a block configuration diagram illustrating an example of functional blocks of the cryptographic communication device 300 according to the first embodiment. FIG. 6 is a flowchart showing an example of a flow of initialization processing S601 in the first embodiment. FIG. 6 is a flowchart showing an example of a flow of update processing S602 in the first embodiment. FIG. 6 is a flowchart showing an example of a flow of temporary key notification processing S603 in the first embodiment. FIG. 4 is a flowchart showing an example of the flow of cryptographic communication processing S604 in the first embodiment. FIG. 10 is a diagram illustrating an example of an overall configuration of an automatic meter reading system 801 according to a third embodiment. FIG. 10 is a diagram illustrating an example of functional blocks of the management server 101 according to the third embodiment. FIG. 9 shows an example of functional blocks of a mobile terminal 201 in Embodiment 3. FIG. 10 is a diagram illustrating an example of functional blocks of a meter-reading meter 301 according to a third embodiment. FIG. 10 is a diagram illustrating an example of detailed functional blocks of a key information management unit 161 in the management server 101 according to the third embodiment. FIG. 10 is a diagram illustrating an example of detailed functional blocks of a management server communication unit 221 in the portable terminal 201 according to the third embodiment. FIG. 10 is a diagram illustrating an example of detailed functional blocks of a meter reading meter communication unit 291 in the portable terminal 201 according to the third embodiment. The figure which shows an example of the detailed functional block of the portable terminal communication part 391 in the meter-reading meter 301 of Embodiment 3. FIG. FIG. 10 is a flowchart showing an example of a flow of temporary key notification processing S603 in the third embodiment. FIG. 11 is a flowchart showing an example of the flow of cryptographic communication processing S604 in the third embodiment. FIG. 10 is a system configuration diagram illustrating an example of an overall configuration of an encryption communication system 800 according to a fourth embodiment. FIG. 6 is a system configuration diagram illustrating an example of an overall configuration of an encryption communication device 500 according to a fourth embodiment. FIG. 20 is a flowchart showing an example of a flow of initialization processing S601 in the fourth embodiment. FIG. 20 is a flowchart showing an example of a flow of update processing S602 in the fourth embodiment. FIG. 18 is a flowchart showing an example of the flow of cryptographic communication processing S604 in the fourth embodiment. FIG. 10 shows an example of the overall configuration of an automatic meter reading system 801 in a fifth embodiment. FIG. 10 is a diagram illustrating an example of functional blocks of a meter-reading meter 301 according to a fifth embodiment. FIG. 18 is a block configuration diagram illustrating an example of functional blocks of the management apparatus 100 according to the sixth embodiment. FIG. 20 is a block configuration diagram illustrating an example of functional blocks of an encryption communication device 200 according to a sixth embodiment. FIG. 18 is a block configuration diagram illustrating an example of functional blocks of an encryption communication device 300 according to a sixth embodiment. FIG. 25 is a flowchart showing an example of the flow of temporary key notification processing S603 in the sixth embodiment. FIG. 19 is a flowchart showing an example of the flow of cryptographic communication processing S604 in the sixth embodiment. FIG. 18 is a block configuration diagram illustrating an example of functional blocks of an encryption communication device 200 according to a seventh embodiment. FIG. 20 is a flowchart showing an example of the flow of cryptographic communication processing S604 in the seventh embodiment. FIG. 20 is a diagram illustrating an example of functional blocks of the management server 101 according to the eighth embodiment. FIG. 20 shows an example of functional blocks of a portable terminal 201 in Embodiment 8. FIG. 18 shows an example of functional blocks of a meter-reading meter 301 in the eighth embodiment. FIG. 20 is a diagram illustrating an example of detailed functional blocks of a reset packet generation unit 166 in the management server 101 according to the eighth embodiment. The figure which shows an example of the detailed functional block of the pair management server communication part 221 and the meter-reading meter communication part 291 in the portable terminal 201 of Embodiment 8. FIG. FIG. 20 is a diagram illustrating an example of detailed functional blocks of a portable terminal communication unit 391 in the meter-reading meter 301 according to the eighth embodiment. FIG. 19 is a flowchart showing an example of the flow of reset packet notification processing S605 in the eighth embodiment. FIG. 19 is a flowchart showing an example of the flow of generation number reset processing S606 in the eighth embodiment.

Embodiment 1 FIG.
The first embodiment will be described with reference to FIGS.

  FIG. 1 is a system configuration diagram showing an example of the overall configuration of the cryptographic communication system 800 in this embodiment.

The cryptographic communication system 800 includes, for example, a management device 100, a cryptographic communication device 200, and a cryptographic communication device 300.
The management device 100 (encryption processing device) stores a master key. The management device 100 generates a temporary key using the stored master key.
The cryptographic communication device 200 (cryptographic processing device) communicates with the management device 100 using a secure method, and acquires the temporary key generated by the management device 100. The cryptographic communication device 200 performs cryptographic communication with the cryptographic communication device 300 using the acquired temporary key.
The cryptographic communication device 300 (cryptographic processing device) stores a master key. The master key stored in the encryption communication device 300 may be the same master key as the master key stored in the management device 100, or a master key corresponding to the master key stored in the management device 100. It may be. The cryptographic communication device 300 generates a temporary key using the stored master key. The temporary key generated by the cryptographic communication device 300 may be the same temporary key as the temporary key generated by the management device 100, or may be a temporary key corresponding to the temporary key generated by the management device 100. The cryptographic communication device 300 performs cryptographic communication with the cryptographic communication device 200 using a temporary key generated by itself.

  FIG. 2 is a hardware configuration diagram illustrating an example of hardware resources of the management device 100, the cryptographic communication device 200, and the cryptographic communication device 300 according to this embodiment.

The management device 100, the encryption communication device 200, and the encryption communication device 300 are, for example, computers. The computer includes, for example, a processing device 911, an input device 912, an output device 913, a storage device 914, and a communication device 915.
The processing device 911 processes the data by executing the computer program stored in the storage device 914 and controls the input device 912, the output device 913, the storage device 914, and the communication device 915.
The storage device 914 stores a computer program executed by the processing device 911, data processed by the processing device 911, and the like.
The input device 912 inputs information from outside the computer and converts it into data that can be processed by the processing device 911. The data converted by the input device 912 may be directly processed by the processing device 911 or may be temporarily stored by the storage device 914. For example, the input device 912 is an operation input device such as a keyboard or a mouse, and inputs an operation by an operator who operates the computer. Alternatively, the input device 912 is a microphone and inputs sound. Alternatively, the input device 912 is a camera and takes an image. Alternatively, the input device 912 is a sensor and measures physical quantities such as temperature and voltage. Alternatively, the input device 912 is an analog / digital conversion circuit, and converts an analog signal into digital data.
The output device 913 converts the data processed by the processing device 911 and the data stored in the storage device 914 and outputs the converted data to the outside of the computer. For example, the output device 913 is a liquid crystal display device and outputs an image. Alternatively, the output device 913 is a speaker and outputs sound. Alternatively, the output device 913 is a digital / analog conversion circuit, and generates an analog signal.
The communication device 915 communicates with other devices. The communication device 915 receives a signal transmitted by another device, inputs information represented by the received signal, and converts it into data that can be processed by the processing device 911. That is, the communication device 915 is a kind of the input device 912. Further, the communication device 915 converts the data processed by the processing device 911 and the data stored by the storage device 914 into a signal and transmits the signal to another device. That is, the communication device 915 is a kind of the storage device 914.

  The functional blocks described below are realized by the processing device 911 executing the computer program stored in the storage device 914. This is an example, and the functional blocks described below may be realized by other configurations. For example, the functional blocks described below may be realized by an electronic circuit such as an analog circuit or a digital circuit, other electrical configurations, mechanical configurations, or other configurations.

  FIG. 3 is a block configuration diagram illustrating an example of functional blocks of the management apparatus 100 in this embodiment.

  The management device 100 includes, for example, a master key storage unit 110, a temporary key generation data storage unit 130, a temporary key generation data update unit 140, a temporary key generation data notification unit 150, and a temporary key generation unit 160. And a temporary key notification unit 170.

  The master key storage unit 110 uses the storage device 914 to store a master key (first master key). The master key stored in the master key storage unit 110 is data used to generate a temporary key used when the cryptographic communication device 200 performs cryptographic communication with the cryptographic communication device 300. In order to prevent leakage of the master key, the master key storage unit 110 may be configured to store the master key using, for example, a tamper-resistant storage device 914. The master key stored in the master key storage unit 110 may be configured in advance and cannot be changed. For example, when the master key is suspected to be leaked, the master key can be changed when necessary. It may be.

  The temporary key generation data storage unit 130 uses the storage device 914 to store temporary key generation data. Similar to the master key stored in the master key storage unit 110, the temporary key generation data stored in the temporary key generation data storage unit 130 is data used to generate a temporary key. Even if the same master key is used, if the temporary key generation data is different, different temporary keys are generated.

  The temporary key generation data update unit 140 uses the processing device 911 to update the temporary key generation data stored in the temporary key generation data storage unit 130. For example, the temporary key generation data update unit 140 repeatedly updates the temporary key generation data stored in the temporary key generation data storage unit 130 every time a predetermined period (for example, one day) elapses. As a result, the generated temporary key changes every time a predetermined period elapses.

The temporary key generation data may be any data as long as the old and new can be distinguished.
For example, the temporary key generation data is data representing a numerical value. When updating the temporary key generation data, the temporary key generation data update unit 140 calculates a sum obtained by adding a predetermined increment value (for example, 1) to the numerical value represented by the temporary key generation data. The temporary key generation data update unit 140 updates the temporary key generation data stored in the temporary key generation data storage unit 130 with data representing the calculated sum. The temporary key generation data storage unit 130 replaces and stores the old temporary key generation data with the updated new temporary key generation data. Thus, since the new temporary key generation data represents a larger numerical value, it is possible to determine which temporary key generation data is newer by comparing the numerical values represented by the two temporary key generation data.

  The temporary key generation unit 160 uses the processing device 911 to generate a temporary key (first temporary key). The temporary key generation unit 160 generates a temporary key using the master key stored in the master key storage unit 110 and the temporary key generation data stored in the temporary key generation data storage unit 130.

The method by which the temporary key generation unit 160 generates a temporary key may be any method as long as it satisfies the following conditions.
The first condition is that the same or similar temporary key is generated if the combination of the master key and the temporary key generation data is the same. A similar temporary key is a group of temporary keys that can generate a ciphertext that can be decrypted with the same key, or that can decrypt a ciphertext that has been encrypted with the same key.
The second condition is that if either the master key or the temporary key generation data is different, a temporary key that is not the same and similar is generated. As a result, when the temporary key generation data is updated, the ciphertext generated using the temporary key generated using the old temporary key generation data before update can be decrypted, or the old temporary key generation before update can be performed. With a key that generates a ciphertext that can be decrypted with the temporary key generated using the data for encryption, the ciphertext generated using the temporary key generated using the updated new temporary key generation data cannot be decrypted, or Ciphertext that can be decrypted with the temporary key generated using the new temporary key generation data after the update cannot be generated.
The third condition is that the master key cannot be estimated from the temporary key generation data and the temporary key generated using the temporary key generation data. Thereby, leakage of the master key can be prevented.

For example, the temporary key generation unit 160 encrypts the temporary key generation data stored in the temporary key generation data storage unit 130 using the master key stored in the master key storage unit 110. The temporary key generation unit 160 uses the encrypted ciphertext as a temporary key.
Alternatively, the temporary key generation unit 160 uses a one-way hash function to store the master key stored in the master key storage unit 110 and the temporary key generation data stored in the temporary key generation data storage unit 130. The hash value is calculated using the hash function input. The temporary key generation unit 160 uses the calculated hash value as a temporary key.

The temporary key notification unit 170 notifies the encryption communication apparatus 200 of the temporary key generated by the temporary key generation unit 160. For example, the temporary key notification unit 170 uses the communication device 915 to transmit the temporary key generated by the temporary key generation unit 160 to the encryption communication device 200.
The method for notifying the temporary key may be any method as long as it can prevent leakage of the temporary key. For example, the temporary key notification unit 170 transmits the temporary key using encrypted communication. Alternatively, the management device 100 and the encryption communication device 200 are directly connected by wire to transmit a temporary key.

  The temporary key generation data notification unit 150 uses the temporary communication key generation unit 160 to generate temporary key generation data used when the temporary key generation unit 160 generates the temporary key notified by the temporary key notification unit 170 to the encryption communication device 200. 200 is notified. For example, the temporary key generation data notification unit 150 uses the communication device 915 to transmit the temporary key stored in the temporary key generation data storage unit 130 to the encryption communication device 200. In order to clarify the correspondence between the temporary key and the temporary key generation data, for example, the temporary key notified by the temporary key notification unit 170 and the temporary key generation data notified by the temporary key generation data notification unit 150 are used. A configuration may be used in which data is transmitted together as one.

  FIG. 4 is a block configuration diagram illustrating an example of functional blocks of the cryptographic communication device 200 according to this embodiment.

  The encryption communication device 200 (first encryption communication device) includes, for example, a temporary key generation data acquisition unit 220, a temporary key generation data storage unit 230, a temporary key generation data notification unit 250, and a temporary key acquisition unit 260. A temporary key storage unit 270, and an encryption communication unit 290.

The temporary key acquisition unit 260 acquires the temporary key (first temporary key) notified from the temporary key notification unit 170 of the management apparatus 100. For example, the temporary key acquisition unit 260 receives the temporary key transmitted by the temporary key notification unit 170 using the communication device 915.
The temporary key storage unit 270 stores the temporary key acquired by the temporary key acquisition unit 260 using the storage device 914. In order to prevent leakage of the temporary key, for example, the temporary key acquisition unit 260 may be configured to store the temporary key using a tamper-resistant storage device 914.

The temporary key generation data acquisition unit 220 acquires the temporary key generation data notified from the temporary key generation data notification unit 150 of the management apparatus 100. For example, the temporary key generation data acquisition unit 220 receives the temporary key generation data transmitted by the temporary key generation data notification unit 150 using the communication device 915.
The temporary key generation data storage unit 230 uses the storage device 914 to store the temporary key generation data acquired by the temporary key generation data acquisition unit 220.

  The temporary key generation data notification unit 250 notifies the encryption communication device 300 of the temporary key generation data stored in the temporary key generation data storage unit 230. For example, the temporary key generation data notification unit 250 transmits the temporary key generation data stored in the temporary key generation data acquisition unit 220 to the encryption communication device 300 using the communication device 915.

  The cryptographic communication unit 290 performs cryptographic communication with the cryptographic communication device 300 using the temporary key stored in the temporary key storage unit 270. For example, the cryptographic communication unit 290 uses the processing device 911 to generate a ciphertext using the temporary key stored in the temporary key notification unit 170, and uses the communication device 915 to generate the ciphertext using the cryptographic communication device 300. Send to. Alternatively, the cipher communication unit 290 receives the ciphertext transmitted by the cipher communication device 300 using the communication device 915, and uses the processing device 911 to store the ciphertext received by the cipher communication unit 290. Decrypt using.

  FIG. 5 is a block configuration diagram illustrating an example of functional blocks of the cryptographic communication device 300 according to this embodiment.

  The cryptographic communication device 300 (second cryptographic communication device) includes, for example, a master key storage unit 310, a temporary key generation data acquisition unit 320, a verification data storage unit 330, a verification data update unit 340, and a temporary key. A generation data verification unit 350, a temporary key generation unit 360, and an encryption communication unit 390 are included.

  The master key storage unit 310 uses the storage device 914 to store a master key (second master key). The master key stored in the master key storage unit 310 is data used to generate a temporary key used when the cryptographic communication device 300 performs cryptographic communication with the cryptographic communication device 200. In order to prevent leakage of the master key, the master key storage unit 310 may be configured to store the master key using a tamper-resistant storage device 914, for example. The master key stored in the master key storage unit 310 may be configured in advance and cannot be changed. For example, when the master key is suspected to be leaked, the master key can be changed when necessary. It may be.

The master key stored in the master key storage unit 310 is combined with the temporary key generation data used by the temporary key generation unit 160 of the management device 100 to generate the temporary key, and the temporary key generated by the temporary key generation unit 160 Any one that can generate the same or a temporary key corresponding to the temporary key may be used. Here, “two temporary keys correspond” refers to a relationship in which a ciphertext encrypted using one temporary key can be decrypted using the other temporary key. “Two master keys correspond” means a relationship in which the same or corresponding temporary key can be generated from two master keys.
The master key stored in the master key storage unit 310 may be the same master key as the master key stored in the master key storage unit 110 of the management apparatus 100, or may be a different master key. When the master key stored in the master key storage unit 310 is different from the master key stored in the master key storage unit 110 of the management device 100, the master key storage of the management device 100 is determined from the master key stored in the master key storage unit 310. The configuration may be such that the master key stored by the unit 110 cannot be estimated. Then, even if the master key stored in the master key storage unit 310 is leaked, it is possible to prevent the master key stored in the master key storage unit 110 of the management apparatus 100 from being known.
When there are a plurality of encryption communication devices 300, the master key storage unit 310 of each encryption communication device 300 may store different master keys. In that case, the temporary key generated using the master key stored in the master key storage unit 310 of a certain cryptographic communication device 300 and the master key stored in the master key storage unit 310 of another cryptographic communication device 300 are generated. The configuration may not correspond to the temporary key. Then, even when the master key stored in the master key storage unit 310 of a certain cryptographic communication device 300 is leaked, it is possible to prevent generation of a temporary key that can be used for cryptographic communication with another cryptographic communication device 300. Can do.

  The verification data storage unit 330 uses the storage device 914 to store verification data. The verification data is data used to verify whether the temporary key generation data notified from the cryptographic communication device 200 is valid.

  The verification data update unit 340 uses the processing device 911 to update the verification data stored in the verification data storage unit 330. For example, the verification data update unit 340 repeatedly updates the verification data stored in the verification data storage unit 330 every time a predetermined period (for example, one day) elapses.

The verification data may be any data as long as it can be determined that the old temporary key generation data is invalid.
For example, the verification data is data representing a numerical value. When updating the verification data, the verification data update unit 340 calculates a sum obtained by adding a predetermined increment value (for example, 1) to the numerical value represented by the verification data. The verification data update unit 340 updates the verification data stored in the verification data storage unit 330 with data representing the calculated sum. The verification data storage unit 330 stores the old verification data by replacing it with the updated new verification data.
The verification data update unit 340 updates the verification data so that the speed at which the numerical value represented by the verification data increases is substantially the same as the speed at which the numerical value represented by the temporary key generation data increases. For example, the verification data update unit 340 updates the verification data in the same cycle as the temporary key generation data update unit 140 of the management apparatus 100 updates the temporary key generation data, and the temporary key generation data represents The same increment value as the increment value added by the temporary key generation data update unit 140 of the management apparatus 100 is added to the numeric value to the numeric value represented by the verification data. Alternatively, the verification data update unit 340 updates the verification data at a cycle that is n times the update cycle of the temporary key generation data (n is a positive real number), and the increment value n of the temporary key generation data is n. The double increment value is added to the numerical value represented by the verification data.

  The temporary key generation data acquisition unit 320 acquires the temporary key generation data notified from the temporary key generation data notification unit 250 of the encryption communication device 200. For example, the temporary key generation data acquisition unit 320 receives the temporary key generation data transmitted by the temporary key generation data notification unit 250 using the communication device 915.

The temporary key generation data verification unit 350 uses the processing device 911 to verify the temporary key generation data acquired by the temporary key generation data acquisition unit 320. The temporary key generation data verification unit 350 uses the verification data stored in the verification data storage unit 330 to determine whether the temporary key generation data acquired by the temporary key generation data acquisition unit 320 is valid. judge.
For example, the temporary key generation data verification unit 350 compares the numerical value represented by the temporary key generation data with the numerical value represented by the verification data. If the numerical value represented by the temporary key generation data is greater than or equal to the numerical value represented by the verification data, the temporary key generation data verification unit 350 determines that the temporary key generation data is valid. When the numerical value represented by the temporary key generation data is smaller than the numerical value represented by the verification data, the temporary key generation data verification unit 350 determines that the temporary key generation data is not valid.

  When the temporary key generation data verification unit 350 determines that the temporary key generation data acquired by the temporary key generation data acquisition unit 320 is valid, the verification data storage unit 330 uses the storage device 914 to enable The temporary key generation data determined by the temporary key generation data verification unit 350 is stored as verification data.

In the initial state, the verification data storage unit 330 stores, for example, data representing the minimum value represented by the temporary key generation data as the first verification data. At this time, the numerical value represented by the verification data stored in the verification data storage unit 330 is always the numerical value represented by the temporary key generation data stored in the temporary key generation data storage unit 130 of the management apparatus 100. It is as follows.
As the verification data update unit 340 updates the verification data stored in the verification data storage unit 330, the numerical value represented by the verification data gradually increases. Further, the temporary key generation data update unit 140 updates the temporary key generation data stored in the temporary key generation data storage unit 130 of the management apparatus 100, so that the numerical value represented by the temporary key generation data gradually increases. . Since both increase speeds are almost the same, the numerical value represented by the verification data stored in the verification data storage unit 330 is always stored in the temporary key generation data storage unit 130 of the management device 100. Or less than the numerical value represented by the temporary key generation data.
Therefore, if the temporary key generation data notifying part 250 notified to the encryption communication apparatus 300 by the temporary key generation data notifying part 250 of the encryption communication apparatus 200 is the latest, the temporary key generation data verification part 350 It is determined that the temporary key generation data acquired by the generation data acquisition unit 320 is valid. Further, at the time of the first validity determination, the numerical value represented by the verification data stored in the verification data storage unit 330 and the numerical value represented by the temporary key generation data stored in the temporary key generation data storage unit 130 of the management device 100 In this case, even if the temporary key generation data notified by the temporary key generation data notification unit 250 of the cryptographic communication device 200 to the cryptographic communication device 300 is not necessarily the latest, the temporary key The generation data verification unit 350 may determine that the temporary key generation data acquired by the temporary key generation data acquisition unit 320 is valid.

  When the temporary key generation data verification unit 350 determines that the temporary key generation data acquired by the temporary key generation data acquisition unit 320 is valid, the temporary key generation data verification unit 350 determines that it is valid. Since the verification data storage unit 330 stores the key generation data as verification data, the temporary key generation data notified by the temporary key generation data notification unit 250 of the cryptographic communication device 200 to the cryptographic communication device 300 is the latest. In this case, at that time, the verification data stored in the verification data storage unit 330 and the temporary key generation data stored in the temporary key generation data storage unit 130 of the management apparatus 100 are the same. That is, the management device 100 and the encryption communication device 300 are synchronized. Therefore, after that, if the temporary key generation data notified by the temporary key generation data notification unit 250 of the cryptographic communication device 200 to the cryptographic communication device 300 is not the latest, the temporary key generation data verification unit 350 Does not determine that the temporary key generation data acquired by the temporary key generation data acquisition unit 320 is valid.

  With this configuration, the management device 100 and the encryption communication device 300 can be easily synchronized.

  Further, when the time of the clock of the encryption communication device 300 is slower than the time of the clock of the management device 100, the speed at which the numerical value represented by the verification data stored in the verification data storage unit 330 increases is the management device 100. The temporary key generation data storage unit 130 stores the temporary key generation data, which is slower than the rate at which the numerical value is increased. However, every time the temporary key generation data notifying unit 250 of the cryptographic communication device 200 notifies the cryptographic communication device 300 of the latest temporary key generation data, the synchronization between the management device 100 and the cryptographic communication device 300 is synchronized. Therefore, the difference between the numerical value represented by the verification data stored in the verification data storage unit 330 and the numerical value represented by the temporary key generation data stored in the temporary key generation data storage unit 130 of the management apparatus 100 increases. Can be prevented.

  If the temporary key generation data verification unit 350 determines that the temporary key generation data acquired by the temporary key generation data acquisition unit 320 is valid, the temporary key generation unit 360 uses the processing device 911 to Is generated. The temporary key generation unit 360 generates a temporary key using the master key stored in the master key storage unit 310 and the temporary key generation data determined by the temporary key generation data verification unit 350 to be valid.

The method by which the temporary key generation unit 360 generates a temporary key may be any method as long as it satisfies the following conditions.
The first condition is that the same or similar temporary key is generated if the combination of the master key and the temporary key generation data is the same.
The second condition is that the master key is a master key that is the same as or corresponds to the master key used by the temporary key generation unit 160 of the management apparatus 100 to generate the temporary key. If the data is the same as the temporary key generation data used by the temporary key generation unit 160 to generate the temporary key, the temporary key that is the same as or corresponds to the temporary key generated by the temporary key generation unit 160 The key is to be generated. On the other hand, in other cases, a temporary key that is not the same as the temporary key generated by the temporary key generation unit 160 and does not correspond to the temporary key generated by the temporary key generation unit 160 is generated.
The third condition is that the temporary key and the master key cannot be inferred from the temporary key generation data and the ciphertext generated using the temporary key generated using the temporary key generation data. Thereby, leakage of a temporary key and a master key can be prevented.

For example, the temporary key generation unit 360 uses the master key stored in the master key storage unit 310 to encrypt the temporary key generation data determined by the temporary key generation data verification unit 350 to be valid. The temporary key generation unit 360 uses the encrypted ciphertext as a temporary key.
Alternatively, the temporary key generation unit 360 uses a one-way hash function to generate the master key stored in the master key storage unit 310 and the temporary key generation data determined by the temporary key generation data verification unit 350 to be valid. The hash value is calculated using the business data as input of the hash function. The temporary key generation unit 360 uses the calculated hash value as a temporary key.

  The cryptographic communication unit 390 performs cryptographic communication with the cryptographic communication device 200 using the temporary key generated by the temporary key generation unit 360. For example, the cryptographic communication unit 390 receives the ciphertext transmitted by the cryptographic communication unit 290 of the cryptographic communication device 200 using the communication device 915 and uses the processing device 911 to convert the received ciphertext to the temporary key generation unit. 360 is decrypted using the temporary key generated. Alternatively, the cryptographic communication unit 390 uses the processing device 911 to generate a ciphertext using the temporary key generated by the temporary key generation unit 360, and uses the communication device 915 to convert the generated ciphertext to the cryptographic communication device 200. Send to.

  The master key stored in the master key storage unit 310 is the same as or corresponding to the master key stored in the master key storage unit 110 of the management apparatus 100. The temporary key generation data acquired by the temporary key generation data acquisition unit 320 is generated when the temporary key generation unit 160 of the management apparatus 100 generates a temporary key that the encryption communication unit 290 of the encryption communication apparatus 200 uses for encryption communication. This is the same data as the temporary key generation data used in the above. Therefore, the temporary key generated by the temporary key generation unit 360 is a temporary key that is the same as or corresponds to the temporary key that the cryptographic communication unit 290 of the cryptographic communication device 200 uses for cryptographic communication. Therefore, the encryption communication unit 390 can decrypt the ciphertext encrypted by the encryption communication unit 290 of the encryption communication device 200, and can generate a ciphertext that can be decrypted by the encryption communication unit 290 of the encryption communication device 200. .

Further, a set of temporary key generation data stored in the temporary key generation data storage unit 230 of the encryption communication device 200 and temporary key stored in the temporary key storage unit 270 leaks, and the temporary key generation data and the temporary key are leaked. Consider a case in which a third party who has obtained a set of and tries to steal information from the cryptographic communication device 300 by performing cryptographic communication with the cryptographic communication device 300.
When the verification data update unit 340 updates the verification data stored in the verification data storage unit 330, the temporary key generation data obtained by the third party and the temporary key generated using the data are not the latest. . For this reason, even if the cipher communication device 300 is notified of the temporary key generation data obtained by a third party, the temporary key generation data verification unit 350 determines that it is not valid. Thereby, it is possible to prevent a third party from performing cryptographic communication with the cryptographic communication device 300.

  Next, the operation will be described.

The processes in the cryptographic communication system 800 are roughly divided into an initialization process S601, an update process S602, a temporary key notification process S603, and a cryptographic communication process S604.
In the initialization process S601, the management device 100 and the cryptographic communication device 300 initialize a master key, temporary key generation data, verification data, and the like.
In the update process S602, the management device 100 and the cryptographic communication device 300 periodically update the temporary key generation data and the verification data.
In the temporary key notification process S603, the management device 100 generates a temporary key and notifies the encrypted communication device 200 of the generated temporary key.
In the encryption communication processing S604, the encryption communication device 200 and the encryption communication device 300 agree on a temporary key used for encryption communication and perform encryption communication.

  FIG. 6 is a flowchart showing an example of the flow of the initialization process S601 in this embodiment.

  In the initialization process S601, the management apparatus 100 executes, for example, a master key storage step S611 and a temporary key generation data initialization step S612.

In the master key storage step S611, the master key storage unit 110 of the management device 100 acquires a master key.
For example, a master key generation device is provided outside the management device 100. The master key storage unit 110 acquires the master key for the management apparatus 100 generated by the master key generation apparatus by communicating with the master key generation apparatus using the communication apparatus 915. Alternatively, a master key generation unit is provided inside the management apparatus 100. The master key storage unit 110 uses the processing device 911 to acquire the master key for the management device 100 generated by the master key generation unit.
The master key storage unit 110 uses the storage device 914 to store the acquired master key.

In the temporary key generation data initialization step S612, the temporary key generation data storage unit 130 of the management apparatus 100 initializes the temporary key generation data.
For example, the temporary key generation data storage unit 130 acquires initial data of temporary key generation data. The initial data acquired by the temporary key generation data storage unit 130 represents, for example, the minimum value represented by the temporary key generation data. Using the storage device 914, the temporary key generation data storage unit 130 stores the acquired initial data as temporary key generation data.

  In the initialization process S601, the cryptographic communication device 300 executes, for example, a master key storage step S631 and a verification data initialization step S632. Note that the cryptographic communication device 300 executes the initialization process S601 regardless of the management device 100. That is, the timing at which the cryptographic communication apparatus 300 executes the initialization process S601 does not have to be the same as the timing at which the management apparatus 100 executes the initialization process S601.

In the master key storage step S631, the master key storage unit 310 of the encryption communication device 300 is the same as or corresponds to the master key stored in the master key storage unit 110 of the management device 100 in the master key storage step S611. To obtain the master key.
For example, the master key storage unit 310 uses the communication device 915 to communicate with the master key generation device, thereby acquiring the master key for the encryption communication device 300 generated by the master key generation device. Alternatively, the master key storage unit 310 uses the communication device 915 to communicate with the management device 100, thereby acquiring the master key for the encryption communication device 300 generated by the master key generation unit of the management device 100.
The master key storage unit 310 uses the storage device 914 to store the acquired master key.

In the verification data initialization step S632, the verification data storage unit 330 of the cryptographic communication device 300 initializes the verification data.
For example, the verification data storage unit 330 acquires initial data of verification data. The initial data acquired by the verification data storage unit 330 represents, for example, the minimum value of the numerical value represented by the temporary key generation data. The verification data storage unit 330 uses the storage device 914 to store the acquired initial data as verification data.

  FIG. 7 is a flowchart showing an example of the flow of the update process S602 in this embodiment.

  In the update process S602, the management device 100 executes, for example, a period elapsed determination process S613 and a temporary key generation data update process S614.

In the cycle elapse determination step S613, the temporary key generation data update unit 140 of the management device 100 determines whether or not a predetermined update cycle has elapsed. For example, the temporary key generation data update unit 140 uses the processing device 911 to compare the elapsed time from the previous update with the update cycle, and when the elapsed time is greater than the update cycle, the update cycle has elapsed. It is determined.
If it is determined that the update cycle has elapsed, the temporary key generation data update unit 140 proceeds to the temporary key generation data update step S614.

In the temporary key generation data update step S614, the temporary key generation data update unit 140 of the management apparatus 100 updates the temporary key generation data.
For example, the temporary key generation data update unit 140 uses the processing device 911 to acquire the temporary key generation data stored in the temporary key generation data storage unit 130. Using the processing device 911, the temporary key generation data update unit 140 calculates a total value obtained by summing up the numerical value represented by the acquired temporary key generation data and a predetermined increment value. The temporary key generation data updating unit 140 updates the temporary key generation data stored in the temporary key generation data storage unit 130 using the data representing the calculated total value. The temporary key generation data storage unit 130 uses the storage device 914 to generate data representing the total value newly calculated by the temporary key generation data update unit 140 instead of the old temporary key generation data. Store as data.
Thereafter, the temporary key generation data update unit 140 returns the process to the cycle elapse determination step S613 and waits for the next update cycle to elapse.

  In the update process S602, the cryptographic communication device 300 executes, for example, a cycle elapse determination step S633 and a verification data update step S634. The cryptographic communication device 300 executes the update process S602 regardless of the management device 100. That is, the timing at which the cryptographic communication apparatus 300 executes the update process S602 does not have to be the same as the timing at which the management apparatus 100 executes the update process S602.

In the cycle elapse determination step S633, the verification data update unit 340 of the encryption communication device 300 determines whether or not a predetermined update cycle has elapsed. For example, the verification data update unit 340 compares the elapsed time from the previous update with the update cycle using the processing device 911, and determines that the update cycle has passed if the elapsed time is greater than the update cycle. To do.
When it is determined that the update cycle has elapsed, the verification data update unit 340 advances the processing to the verification data update step S634.

In the verification data update step S634, the verification data update unit 340 of the cryptographic communication device 300 updates the verification data.
For example, the verification data update unit 340 uses the processing device 911 to acquire the verification data stored in the verification data storage unit 330. The verification data update unit 340 uses the processing device 911 to calculate a total value obtained by summing the numerical value represented by the acquired verification data and a predetermined increment value. The verification data update unit 340 uses the data representing the calculated total value to update the verification data stored in the verification data storage unit 330. The verification data storage unit 330 stores data representing the total value newly calculated by the verification data update unit 340 as verification data using the storage device 914 instead of the old verification data.
Thereafter, the verification data update unit 340 returns the process to the cycle elapse determination step S633 and waits for the next update cycle to elapse.

  FIG. 8 is a flowchart showing an example of the flow of the temporary key notification process S603 in this embodiment.

In the temporary key notification process S603, the management device 100 executes, for example, a temporary key request reception step S615, a temporary key generation step S616, a temporary key notification step S618, and a temporary key generation data notification step S619.
Also, in the temporary key notification process S603, the cryptographic communication apparatus 200 executes, for example, a temporary key request process S621, a temporary key acquisition process S622, and a temporary key generation data acquisition process S623.

In the temporary key request step S621, the temporary key acquisition unit 260 of the cryptographic communication device 200 requests the management device 100 for a temporary key. For example, the temporary key acquisition unit 260 uses the communication device 915 to transmit a temporary key request message requesting a temporary key to the management device 100.
In the temporary key request reception step S615, the temporary key notification unit 170 of the management device 100 receives a request from the encryption communication device 200. For example, the temporary key notification unit 170 receives the temporary key request message transmitted by the temporary key acquisition unit 260 of the encryption communication device 200 using the communication device 915.

  The management apparatus 100 may authenticate the encryption communication apparatus 200 in order to confirm whether or not the encryption communication apparatus 200 may be notified of the temporary key. For example, the encryption communication device 200 is provided with an authentication information input unit, and the management device 100 is provided with an authentication information verification unit. The authentication information input unit of the encryption communication device 200 uses the input device 912 to input biometric information such as a user's fingerprint and authentication information such as a password. Using the processing device 911, the temporary key acquisition unit 260 of the encryption communication device 200 generates a temporary key request message including the authentication information input by the authentication information input unit. The authentication information verification unit of the management device 100 authenticates the cryptographic communication device 200 by using the processing device 911 to verify the authentication information included in the temporary key request message notified from the cryptographic communication device 200. If the authentication fails, the management apparatus 100 ends the temporary key notification process S603 without executing the subsequent steps. Thereby, it is possible to prevent the management apparatus 100 from notifying the encryption communication apparatus 200 of the temporary key when a person other than the authorized user is operating the encryption communication apparatus 200.

  In the temporary key generation step S616, the temporary key generation unit 160 of the management device 100 uses the processing device 911 to store the master key stored in the master key storage unit 110 and the temporary key stored in the temporary key generation data storage unit 130. A temporary key is generated based on the generation data.

In the temporary key notification step S618, the temporary key notification unit 170 of the management device 100 notifies the encryption communication device 200 of the temporary key generated by the temporary key generation unit 160 in the temporary key generation step S616.
In the temporary key acquisition step S622, the temporary key acquisition unit 260 of the cryptographic communication device 200 acquires the temporary key notified by the temporary key notification unit 170 of the management device 100 in the temporary key notification step S618. The temporary key storage unit 270 of the encryption communication device 200 stores the temporary key acquired by the temporary key acquisition unit 260 using the storage device 914.

In the temporary key generation data notification step S619, the temporary key generation data notification unit 150 of the management device 100 temporarily stores the temporary key notified to the encryption communication device 200 by the temporary key notification unit 170 in the temporary key notification step S618. Temporary key generation data used when the temporary key generation unit 160 generates in the key generation step S616 is notified to the encryption communication device 200.
In the temporary key generation data acquisition step S623, the temporary key generation data acquisition unit 220 of the cryptographic communication device 200 receives the temporary key notified by the temporary key generation data notification unit 150 of the management device 100 in the temporary key generation data notification step S619. Get key generation data. The temporary key generation data storage unit 230 of the encryption communication device 200 stores the temporary key generation data acquired by the temporary key generation data acquisition unit 220 using the storage device 914.

  FIG. 9 is a flowchart showing an example of the flow of the cryptographic communication processing S604 in this embodiment.

In the cryptographic communication process S604, the cryptographic communication device 200 executes, for example, a temporary key generation data notification step S624 and a cryptographic communication step S625.
Further, in the cryptographic communication process S604, the cryptographic communication device 300 executes, for example, a temporary key generation data acquisition step S635, a temporary key generation data verification step S636, a temporary key generation step S637, and a cryptographic communication step S638. To do.

In the temporary key generation data notification step S624, the temporary key generation data notification unit 250 of the cryptographic communication apparatus 200 notifies the cryptographic communication apparatus 300 of the temporary key generation data stored in the temporary key generation data storage unit 230. To do.
In the temporary key generation data acquisition step S635, the temporary key generation data acquisition unit 320 of the cryptographic communication device 300 notifies the temporary key generation data notification unit 250 of the cryptographic communication device 200 in the temporary key generation data notification step S624. Get temporary key generation data.

  Note that the cryptographic communication device 200 includes not only temporary key generation data but also information necessary for starting cryptographic communication with the cryptographic communication device 300 such as identification data and authentication information for identifying the cryptographic communication device 200. The encryption communication device 300 may be notified.

In the temporary key generation data verification step S636, the temporary key generation data verification unit 350 of the cryptographic communication device 300 uses the processing device 911 to verify the verification data stored in the verification data storage unit 330 and the temporary key generation data. Based on the temporary key generation data acquired by the data acquisition unit 320, it is determined whether or not the temporary key generation data is valid.
If the temporary key generation data verification unit 350 determines that the temporary key generation data is not valid, the cryptographic communication apparatus 300 does not execute the subsequent steps and ends the cryptographic communication process S604.
When the temporary key generation data verification unit 350 determines that the temporary key generation data is valid, the verification data storage unit 330 uses the storage device 914 to replace the verification data stored so far. The temporary key generation data determined by the temporary key generation data verification unit 350 as valid is stored as new verification data. Thereby, the management apparatus 100 and the encryption communication apparatus 300 are gently synchronized.

  The encryption communication device 300 may be configured to notify the verification result to the encryption communication device 200. Also, the cryptographic communication device 300 transmits not only the verification result but also information necessary for starting cryptographic communication with the cryptographic communication device 200 such as identification data for identifying the cryptographic communication device 300 and authentication information. 200 may be configured to transmit to 200.

  In the temporary key generation step S637, the temporary key generation unit 360 of the cryptographic communication device 300 uses the processing device 911 and the master key stored in the master key storage unit 310, and the temporary key generation data verification unit 350 that is valid. A temporary key is generated based on the temporary key generation data determined by.

In the cryptographic communication step S625, the cryptographic communication unit 290 of the cryptographic communication device 200 performs cryptographic communication with the cryptographic communication device 300 using the temporary key stored in the temporary key storage unit 270.
In the cryptographic communication step S638, the cryptographic communication unit 390 of the cryptographic communication device 300 performs cryptographic communication with the cryptographic communication device 200 using the temporary key generated by the temporary key generation unit 360 in the temporary key generation step S637.
For example, the cryptographic communication unit 290 of the cryptographic communication device 200 uses the processing device 911 to generate a ciphertext using the temporary key stored in the temporary key storage unit 270 and uses the communication device 915 to generate the ciphertext generated. Is transmitted to the cryptographic communication apparatus 300. The encryption communication unit 390 of the encryption communication device 300 receives the ciphertext transmitted by the encryption communication device 200 using the communication device 915, and uses the temporary key generated by the temporary key generation unit 360 using the processing device 911. To decrypt the ciphertext. Also, the cryptographic communication unit 390 of the cryptographic communication device 300 uses the processing device 911 to generate a ciphertext using the temporary key generated by the temporary key generation unit 360 and uses the communication device 915 to generate the ciphertext generated. Is transmitted to the cryptographic communication apparatus 200. The encryption communication unit 290 of the encryption communication device 200 receives the ciphertext transmitted by the encryption communication device 300 using the communication device 915 and uses the temporary key stored in the temporary key storage unit 270 using the processing device 911. And decrypts the received ciphertext.

  Instead of starting the encryption communication immediately, the information necessary for starting the encryption communication is encrypted using the agreed temporary key between the encryption communication device 200 and the encryption communication device 300. The structure which communicates may be sufficient. For example, the cryptographic communication device 200 and the cryptographic communication device 300 perform mutual authentication based on the exchanged information. Alternatively, the encryption communication device 200 and the encryption communication device 300 agree on a key to be used for encryption communication based on the exchanged information, and perform encryption communication using the agreed key.

  As described above, by determining the validity of the temporary key generation data, it is possible to prevent the cryptographic communication device 200 and the cryptographic communication device 300 from performing cryptographic communication using the old temporary key.

  For example, when the cryptographic communication device 200 is small and portable, there is a possibility that a legitimate user of the cryptographic communication device 200 loses the cryptographic communication device 200 and a third party picks up the cryptographic communication device 200 and misuses it. is there. If the temporary key stored in the cryptographic communication device 200 picked up by the third party becomes old due to the update of the verification data, the cryptographic communication device 200 performs cryptographic communication with the cryptographic communication device 300. I can't. For this reason, it is possible to prevent information from leaking from the encryption communication device 300. The cryptographic communication apparatus 200 stores a temporary key and temporary key generation data, but does not store a master key. Since the master key cannot be estimated from the temporary key and the temporary key generation data, even if a third party who picks up the cryptographic communication device 200 extracts the temporary key or temporary key generation data from the cryptographic communication device 200 The master key will not be leaked.

Embodiment 2. FIG.
The second embodiment will be described.
In addition, about the part which is common in Embodiment 1, the same code | symbol is attached | subjected and description is abbreviate | omitted.

  Since the overall configuration of the cryptographic communication system 800 and the hardware configuration and block configuration of the management device 100 and the cryptographic communication devices 200 and 300 in this embodiment are the same as those in the first embodiment, only different parts will be described.

  In the cryptographic communication apparatus 300, the temporary key generation data verification unit 350 determines that the temporary key generation data acquired by the temporary key generation data acquisition unit 320 is valid, and the verification data storage unit 330 determines that the temporary key generation data is valid. When the generation data is stored as verification data, the verification data update unit 340 resets the elapsed time from the previous update. That is, the verification data update unit 340 includes a verification data storage unit when an elapsed time after the verification data storage unit 330 stores the temporary key generation data as verification data reaches a predetermined update period. The verification data stored in 330 is updated.

  When the clock of the cryptographic communication device 300 is not accurate and the clock of the cryptographic communication device 300 advances faster than the clock of the management device 100, the numerical value represented by the verification data stored in the verification data storage unit 330 increases. Is faster than the speed at which the numerical value represented by the temporary key generation data stored in the temporary key generation data storage unit 130 of the management apparatus 100 increases. As it is, in any case, the numerical value represented by the verification data stored in the verification data storage unit 330 is larger than the numerical value represented by the temporary key generation data stored in the temporary key generation data storage unit 130 of the management apparatus 100. Thus, even with the latest temporary key generation data, it is determined that the temporary key generation data verification unit 350 is not valid, so that encrypted communication between the encrypted communication device 200 and the encrypted communication device 300 cannot be performed.

  When the temporary key generation data verification unit 350 determines that the temporary key generation data notified from the encryption communication device 200 to the encryption communication device 300 is valid, the management device 100 stores the temporary key generation data storage unit. A certain amount of time has already passed since the temporary key generation data update unit 140 updates the temporary key generation data stored in 130. Therefore, in the cryptographic communication apparatus 300, if the verification data update unit 340 measures the elapsed time from that time, the next update of the verification data is slower than the update of the temporary key generation data in the management apparatus 100. Therefore, if the encryption communication device 200 and the encryption communication device 300 communicate with each other on a regular basis, even if the clock of the encryption communication device 300 advances faster than the clock of the management device 100, the verification data storage unit The speed at which the numerical value represented by the verification data stored in 330 is increased can be prevented from becoming faster than the speed at which the numerical value represented by the temporary key generation data stored in the temporary key generation data storage unit 130 is increased.

Embodiment 3 FIG.
The third embodiment will be described with reference to FIGS.
Note that portions common to Embodiment 1 or Embodiment 2 are denoted by the same reference numerals and description thereof is omitted.

  FIG. 10 is a diagram showing an example of the overall configuration of the automatic meter reading system 801 in this embodiment.

The automatic meter reading system 801 (encryption communication system) includes, for example, a management server 101, a portable terminal 201, and a meter reading meter 301.
The meter-reading meter 301 and the portable terminal 201 communicate using the wireless network 802. The portable terminal 201 and the management server 101 communicate using the public network 803. The communication between the portable terminal 201 and the management server 101 uses a secure communication path such as SSL (Secure Socket Layer). Wireless communication and public network communication are not necessarily performed simultaneously.
Note that there are usually a plurality of portable terminals 201 and meter-reading meters 301.

  The hardware configuration of the management server 101, the portable terminal 201, and the meter-reading meter 301 is the same as, for example, the management device 100, the encryption communication device 200, and the encryption communication device 300 described in the first embodiment.

  FIG. 11 is a diagram showing an example of functional blocks of the management server 101 in this embodiment.

  The management server 101 (management device) includes, for example, a master key storage unit 111, a generation number counter 131, and a key information management unit 161.

  The master key storage unit 111 stores a master key 411 (first master key). The master key 411 is a key used in common key encryption, and the meter-reading meter 301 has the same key. When there are a plurality of meter-reading meters 301, a configuration in which a plurality of meter-reading meters 301 use a common master key may be used, or a configuration in which a different master key is used for each meter-reading meter 301 may be used.

  The generation number counter 131 (temporary key generation data storage unit) stores a generation number 412 (temporary key generation data). The generation number counter 131 (temporary key generation data update unit) increments the generation number 412 in synchronization with the date. Alternatively, the generation number counter 131 may be configured to increment the generation number 412 every time a certain period (for example, 24 hours) elapses.

  The key information management unit 161 receives the temporary key issue request 421 from the portable terminal 201. The key information management unit 161 receives the generation number 412 from the generation number counter 131. The key information management unit 161 receives the master key 411 from the master key storage unit 111. The key information management unit 161 (temporary key generation unit) generates a temporary key 413 (first temporary key) from the master key 411 and the generation number 412. The key information management unit 161 (temporary key notification unit / temporary key generation data notification unit) sends the temporary key 413 and the generation number 412 to the portable terminal 201.

  FIG. 12 is a diagram showing an example of functional blocks of the mobile terminal 201 in this embodiment.

  The portable terminal 201 (first encryption communication device) includes, for example, a management server communication unit 221, a message generation unit 281, and a meter reading meter communication unit 291.

The management server communication unit 221 sends a temporary key issue request 421 to the key information management unit 161 of the management server 101. The management server communication unit 221 may be configured to send a password, biometrics such as a fingerprint, and other authentication information as part of the temporary key issue request 421. Also, the management server communication unit 221 sends the key type information 422 as a temporary key issue request 421. The key type information 422 indicates the type of key to be used. Thereby, when a master key differs for every meter-reading meter 301 etc., a some key can be used properly according to a use.
The management server communication unit 221 (temporary key acquisition unit / temporary key generation data acquisition unit) receives the temporary key 413 and the generation number 412 from the management server 101. The pair management server communication unit 221 passes the received temporary key 413 and the generation number 412 to the pair meter reading meter communication unit 291.

  The message generation unit 281 generates a message 423 for the meter-reading meter 301.

The meter reading meter communication unit 291 communicates with the meter reading meter 301.
For example, the meter reading meter communication unit 291 receives the message 423 generated by the message generation unit 281. The meter reading meter communication unit 291 encrypts the message 423 with the temporary key 413. The meter reading meter communication unit 291 generates a message identifier. The meter reading meter communication unit 291 generates an encrypted message 424 by concatenating the ciphertext obtained by encrypting the message 423, the message identifier, and the generation number 412. The meter reading meter communication unit 291 (temporary key generation data notifying unit / encrypted communication unit) sends an encrypted message 424 to the meter reading meter 301.
Further, the meter reading meter communication unit 291 (encrypted communication unit) receives the encrypted response 434 from the meter reading meter 301. The meter reading meter communication unit 291 decrypts the encrypted response 434 with the temporary key 413.

  FIG. 13 is a diagram showing an example of functional blocks of the meter-reading meter 301 in this embodiment.

  The meter-reading meter 301 (second encryption communication device) includes, for example, a master key storage unit 311, a generation number counter 331, a message processing unit 381, and a portable terminal communication unit 391.

  The master key storage unit 311 stores a master key 431 (second master key).

  The generation number counter 331 (verification data storage unit) stores a generation number 432 (verification data). The generation number counter 331 (verification data update unit) increments the generation number 432 in synchronization with the date. Alternatively, the generation number counter 331 may be configured to increment the generation number 432 every time a certain period (for example, 24 hours) elapses.

The mobile terminal communication unit 391 communicates with the mobile terminal 201.
For example, the mobile terminal communication unit 391 (temporary key generation data acquisition unit) receives the encrypted message 424. The mobile terminal communication unit 391 acquires the generation number 432 from the generation number counter 331. The mobile terminal communication unit 391 (temporary key generation data verification unit) compares the generation number 432 with the generation number 412 included in the encrypted message 424.
When the generation number 432 is newer than the generation number 412, the mobile terminal communication unit 391 discards the encrypted message 424 and sends an error message to the mobile terminal 201 as the encrypted response 434.
If the generation number 432 is the same as or older than the generation number 412, the mobile terminal communication unit 391 acquires the master key 431 from the master key storage unit 311. The mobile terminal communication unit 391 (temporary key generation unit) generates a temporary key (second temporary key) from the generation number 412 and the master key 431. The mobile terminal communication unit 391 generates the same key as the temporary key 413. The mobile terminal communication unit 391 (encryption communication unit) decrypts the encrypted message 424 with the generated temporary key and reproduces the message 423. The mobile terminal communication unit 391 verifies the reproduced message 423.
If the verification is successful, the mobile terminal communication unit 391 sends a message 423 to the message processing unit 381. When the generation number 432 is older than the generation number 412, the mobile terminal communication unit 391 overwrites the generation number 412 on the generation number counter 331.

  Alternatively, the mobile terminal communication unit 391 receives the response 433 generated by the message processing unit 381. The mobile terminal communication unit 391 acquires the generation number 432 from the generation number counter 331. The mobile terminal communication unit 391 acquires the master key 431 from the master key storage unit 311. The mobile terminal communication unit 391 (temporary key generation unit) generates a temporary key (second temporary key) from the generation number 432 and the master key 431. The mobile terminal communication unit 391 (encryption communication unit) encrypts the response 433. The mobile terminal communication unit 391 generates a message authenticator. The mobile terminal communication unit 391 generates an encryption response 434. The mobile terminal communication unit 391 sends the encryption response 434 to the meter reading meter communication unit 291 of the mobile terminal 201.

  The message processing unit 381 processes the message 423 decoded by the meter reading meter communication unit 291 and generates a response 433. The message processing unit 381 sends a response 433 to the mobile terminal communication unit 391.

  FIG. 14 is a diagram showing an example of detailed functional blocks of the key information management unit 161 in the management server 101 of this embodiment.

  The key information management unit 161 includes, for example, an authentication unit 162, a master key selection unit 163, a temporary key generation unit 164, and an output determination unit 171.

The authentication unit 162 receives the temporary key issue request 421 from the mobile terminal 201 (to the management server communication unit 221). The authentication unit 162 determines whether to process the temporary key issue request 421 based on the authentication information included in the temporary key issue request 421. For example, the authentication unit 162 authenticates the sender based on the authentication information. When it is determined not to process the temporary key issue request 421, the authentication unit 162 outputs an output determination signal 414 indicating that the key is not output to the output determination unit 171. When it is determined to process the temporary key issue request 421, the authentication unit 162 separates the key type information 422 from the temporary key issue request 421. The authentication unit 162 passes the key type information 422 to the master key selection unit 163.
If authentication is not performed, the authentication unit 162 may not be provided.

Based on the key type information 422, the authentication unit 162 selects the master key 411 used for temporary key generation from the plurality of master keys 411 stored in the master key storage unit 111 based on the key type information 422. When the master key 411 corresponding to the key type information 422 does not exist among the plurality of master keys 411 stored in the master key storage unit 111, the master key selection unit 163 outputs an output determination signal 414 indicating that no key is output. Is output to the output determination unit 171.
Note that when the master key 411 stored in the master key storage unit 111 is one type, the master key selection unit 163 may not be provided.

  The temporary key generation unit 164 acquires the master key 411 selected by the master key selection unit 163 and the generation number 412 stored by the generation number counter 131. The temporary key generation unit 164 generates a temporary key 413 based on the master key 411 and the generation number 412. For example, the temporary key generation unit 164 generates, as the temporary key 413, data obtained by encrypting the generation number 412 with the master key 411 by a predetermined encryption method. Alternatively, the temporary key generation unit 164 generates a hash value as a temporary key 413 using a keyed hash function with the generation number 412 and the master key 411 as inputs. Note that the key generation method used by the temporary key generation unit 164 to generate the temporary key 413 is that the temporary key 413 is uniquely generated from the generation number 412 and the master key 411, and that the temporary key 413 and the generation number 412 Therefore, it is necessary that the master key 411 is not estimated.

  The generation number counter 131 has a generation number 412. After a certain period (for example, one day), the generation number counter 131 increments the generation number 412 by one.

The output determination unit 171 (temporary key notification unit / temporary key generation data notification unit) determines whether to output the temporary key 413 and the generation number 412 generated by the temporary key generation unit 164.
When the output determination signal 414 indicating that the key is not output is received from the authentication unit 162 or the master key selection unit 163, the output determination unit 171 does not output the temporary key 413 and the generation number 412. Alternatively, the output determination unit 171 may be configured to output a predetermined error code to the mobile terminal 201 (to the management server communication unit 221) instead.
When the output determination signal 414 indicating that the key is not output is not received from the authentication unit 162 or the master key selection unit 163, the output determination unit 171 sends the temporary key 413 and the generation number 412 to the portable terminal 201 (to the management server communication unit). 221).

  FIG. 15 is a diagram illustrating an example of detailed functional blocks of the management server communication unit 221 in the portable terminal 201 according to this embodiment.

  The management server communication unit 221 includes, for example, a temporary key issue request generation unit 222 and a temporary key information acquisition unit 223.

For example, the temporary key issue request generation unit 222 receives key type information 422 and authentication information 425 from the input device 912. The input device 912 is a character string input device such as a keyboard, for example. Alternatively, the input device 912 is a device that acquires biometric information such as a fingerprint reader. The temporary key issue request generator 222 stores the key type information 422 in a predetermined storage area of the storage device 914.
The temporary key issue request generator 222 generates a temporary key issue request 421 based on the acquired authentication information 425 and key type information 422. The temporary key issue request 421 generated by the temporary key issue request generator 222 includes authentication information 425 and key type information 422.
The temporary key issue request generation unit 222 sends a temporary key issue request 421 to the management server 101 (key information management unit 161).
When the management server 101 does not perform user authentication, the temporary key issuance request generation unit 222 may be configured not to acquire the authentication information 425. In that case, the temporary key issue request 421 may be configured not to include the authentication information 425.
Further, when there is only one type of key to be used, the temporary key issue request generation unit 222 may be configured not to acquire the key type information 422 from the input device 912. In this case, the temporary key issue request generation unit 222 may be configured to generate the key type information 422 internally. Alternatively, the temporary key issue request 421 may be configured not to include the key type information 422.

  When a response to the temporary key issue request 421 is received from the management server 101, the temporary key issue request generation unit 222 sends the key type information 422 to the counter meter communication unit 291.

  The temporary key information acquisition unit 223 (temporary key acquisition unit / temporary key generation data acquisition unit) receives the temporary key 413 and the generation number 412 from the management server 101. The temporary key information acquisition unit 223 sends the temporary key 413 and the generation number 412 to the counter meter communication unit 291.

  FIG. 16 is a diagram illustrating an example of detailed functional blocks of the meter reading meter communication unit 291 in the mobile terminal 201 of this embodiment.

  The meter reading meter communication unit 291 includes, for example, an encryption unit 292, a multiplexing unit 293, a separation unit 294, a decryption unit 295, and a reception determination unit 296.

  The message generation unit 281 generates a message 423 to be transmitted to the mobile terminal 201. The message generation unit 281 sends the message 423 to the encryption unit 292.

The encryption unit 292 receives the temporary key 413 from the management server communication unit 221. The encryption unit 292 encrypts the message 423 with the temporary key 413. The encryption unit 292 generates a message authenticator. The encryption unit 292 generates the ciphertext 426. The ciphertext 426 includes a ciphertext body obtained by encrypting the message 423 and a message authenticator.
For example, the encryption unit 292 executes common key encryption such as AES (Advanced Encryption Standard) and TDES (Triple Data Encryption Standard) in a predetermined usage mode, and encrypts the message 423.
For example, the encryption unit 292 executes a common key encryption such as AES or TDES in a predetermined usage mode to generate a message authenticator. Alternatively, the encryption unit 292 executes a keyed cryptographic hash or the like to generate a message authenticator.

  The multiplexing unit 293 receives the key type information 422 and the key type information 422 from the management server communication unit 221. The multiplexing unit 293 generates the encrypted message 424 by multiplexing the key type information 422, the generation number 412 and the ciphertext 426. The multiplexing unit 293 (temporary key generation data notification unit, encryption communication unit) sends the encrypted message 424 to the portable terminal 201 (counter meter communication unit 291).

  The separation unit 294 receives the encrypted response 434 from the portable terminal 201 (the meter reading meter communication unit 291). The separation unit 294 separates the encrypted response 434 into the ciphertext 436 and the generation number 432.

The decryption unit 295 receives the temporary key 413 from the management server communication unit 221. The decryption unit 295 decrypts the ciphertext 436 using the temporary key 413 and generates a response 433. The decryption unit 295 decrypts the ciphertext 436 using a decryption method corresponding to the encryption method used by the portable terminal communication unit 391 in the meter-reading meter 301.
In addition, the decryption unit 295 performs message verification of the ciphertext 436 and generates a verification result 427. The decryption unit 295 verifies the ciphertext 436 using a verification method corresponding to the message authenticator generation method used by the portable terminal communication unit 391 in the meter-reading meter 301.
The decryption unit 295 outputs the response 433 and the verification result 427.

The reception determination unit 296 receives the generation number 412 from the management server communication unit 221. The reception determination unit 296 performs output determination based on the generation number 412, the generation number 432, and the verification result 427. Judgment criteria are as follows.
When the decryption unit 295 fails in message verification, the response 433 is not output.
If the generation number 432 is older than the generation number 412, the response 433 is not output.
If the decryption unit 295 succeeds in the message verification and the generation number 432 is the same as or newer than the generation number 412, a response 433 is output.
In the case of the determination result that the response 433 is output, the reception determination unit 296 outputs the response 433 to the message generation unit 281.

  FIG. 17 is a diagram illustrating an example of detailed functional blocks of the portable terminal communication unit 391 in the meter-reading meter 301 according to this embodiment.

  The mobile terminal communication unit 391 includes, for example, a master key selection unit 363, a temporary key generation unit 364, an encryption unit 392, a multiplexing unit 393, a separation unit 394, a decryption unit 395, and a reception determination unit 396. And have.

  The separation unit 394 receives the encrypted message 424 from the mobile terminal 201 (the meter reading meter communication unit 291). The separation unit 394 separates the encrypted message 424 into key type information 422, ciphertext 426, and generation number 412.

  Based on the key type information 422, the master key selection unit 363 selects the master key 431 used for generating the temporary key 435 from the plurality of master keys 431 stored in the master key storage unit 311.

  The temporary key generation unit 364 generates a temporary key 435 from the master key 431 selected by the master key selection unit 363 and the generation number 412. The temporary key generation unit 364 generates the temporary key 435 by the same temporary key generation method as the temporary key generation unit 164 of the key information management unit 161 in the management server 101.

The decryption unit 395 decrypts the ciphertext 426 using the temporary key 435 and generates a message 423. The decryption unit 395 decrypts the ciphertext 426 using a decryption method corresponding to the encryption method used by the encryption unit 292 of the meter reading meter communication unit 291 in the portable terminal 201.
In addition, the decryption unit 395 performs message verification of the ciphertext 426 and generates a verification result 437. The decryption unit 395 verifies the ciphertext 426 using a verification method corresponding to the message authenticator generation method used by the encryption unit 292 of the meter reading meter communication unit 291 in the portable terminal 201.
The decryption unit 395 outputs the ciphertext 426 and the verification result 437.

The reception determination unit 396 acquires the generation number 432 from the generation number counter 331. The reception determination unit 396 performs output determination based on the generation number 432, the generation number 412, and the verification result 437. Judgment criteria are as follows.
If the decryption unit 395 fails in message verification, the message 423 is not output.
If the generation number 412 is older than the generation number 432, the message 423 is not output.
When the decryption unit 395 succeeds in the message verification and the generation number 412 is the same as or newer than the generation number 432, the message 423 is output.
If it is determined that the message 423 is to be output, the reception determination unit 396 outputs the message 423 to the message processing unit 381.
If the message verification is successful and the generation number 412 is newer than the generation number 432, the reception determination unit 396 rewrites the value stored in the generation number counter 331 to the generation number 412.

  The generation number counter 331 increases the generation number 432 held by one when a certain period (for example, one day) has elapsed since the generation number 432 to be held is changed.

  The encryption unit 392 receives the response 433 from the message processing unit 381. The encryption unit 392 encrypts the response 433 using the temporary key 435. Further, the encryption unit 392 generates a message authenticator. The encryption unit 392 generates the ciphertext 436. For example, the encryption unit 392 generates the ciphertext 436 using the same encryption method and message authenticator generation method as the encryption unit 292 of the meter reading meter communication unit 291 in the portable terminal 201.

  The multiplexing unit 393 multiplexes the key type information 422, the generation number 432, and the ciphertext 436 to generate an encryption response 434. The multiplexing unit 393 sends the encryption response 434 to the portable terminal 201 (counter meter communication unit 291).

  Next, the operation will be described.

  FIG. 18 is a flowchart showing an example of the flow of the temporary key notification processing S603 in this embodiment.

  The temporary key notification processing S603 includes, for example, a temporary key issue request generation step S641, an authentication step S642, a master key selection step S643, a temporary key generation step S644, an output step S645, and a temporary key information acquisition step S646. Have.

In the temporary key issue request generation step S <b> 641, the temporary key issue request generation unit 222 of the mobile terminal 201 generates a temporary key issue request 421. The temporary key issue request generation unit 222 transmits a temporary key issue request 421 to the management server 101 (key information management unit 161).
In the authentication step S642, the authentication unit 162 of the management server 101 receives the temporary key issue request 421. The authentication unit 162 verifies the temporary key issue request 421. If the verification fails, the authentication unit 162 ends the temporary key notification process S603. If the verification is successful, the authentication unit 162 separates the key type information 422 from the temporary key issuance request 421 and proceeds to the master key selection step S643.
In the master key selection step S643, the master key selection unit 163 of the management server 101 selects the master key 411 based on the key type information 422. If the key type information 422 is invalid, the master key selection unit 163 ends the temporary key notification process S603. If the key type information 422 is correct, the master key selection unit 163 advances the process to the temporary key generation step S644.
In the temporary key generation step S 644, the temporary key generation unit 164 of the management server 101 generates a temporary key 413 based on the master key 411 and the generation number 412.
In the output step S645, the output determination unit 171 of the management server 101 transmits the temporary key 413 and the generation number 412 to the mobile terminal 201 (to the management server communication unit 221).
In the temporary key information acquisition step S646, the temporary key information acquisition unit 223 of the mobile terminal 201 receives the temporary key 413 and the generation number 412. The temporary key information acquisition unit 223 outputs the temporary key 413 and the generation number 412 to the counter meter reading unit 291. The temporary key issue request generation unit 222 outputs the key type information 422 to the meter reading meter communication unit 291.
At this time, communication between the management server 101 and the mobile terminal 201 may be disconnected.

  FIG. 19 is a flowchart showing an example of the flow of the cryptographic communication process S604 in this embodiment.

  The encryption communication process S604 includes, for example, an encryption step S651, a multiplexing step S652, a separation step S653, a master key selection step S654, a temporary key generation step S655, a decryption step S656, and a reception determination step S657. A message processing step S660, a master key selection step S671, a temporary key generation step S672, an encryption step S673, a multiplexing step S674, a separation step S675, a decryption step S676, and a reception determination step S677.

In the encryption step S651, the encryption unit 292 of the mobile terminal 201 encrypts the message 423 using the temporary key 413 and generates a ciphertext 426.
In the multiplexing step S652, the multiplexing unit 293 of the mobile terminal 201 multiplexes the ciphertext 426, the generation number 412 and the key type information 422 to generate an encrypted message 424. The multiplexing unit 293 transmits the encrypted message 424 to the meter-reading meter 301 (for the portable terminal communication unit 391).
In the separation step S653, the separation unit 394 of the meter-reading meter 301 receives the encrypted message 424. The separation unit 394 separates the encrypted message 424 into a ciphertext 426, a generation number 412 and key type information 422.
In the master key selection step S654, the master key selection unit 363 of the meter-reading meter 301 selects the master key 431 based on the key type information 422. The master key selection unit 363 stores key type information 422.
In the temporary key generation step S655, the temporary key generation unit 364 of the meter-reading meter 301 generates a temporary key 435 based on the master key 431 and the generation number 412.
In the decryption step S656, the decryption unit 395 of the meter-reading meter 301 decrypts the ciphertext 426 using the temporary key 435, and generates a message 423 and a verification result 437.
In the reception determination step S657, the reception determination unit 396 of the meter-reading meter 301 determines whether to output the message 423 based on the generation number 412, the generation number 432, and the verification result 437. When it is determined that the message 423 is not output, the reception determination unit 396 ends the encryption communication process S604. When it is determined that the message 423 is output, the reception determination unit 396 outputs the message 423. The generation number counter 331 stores the generation number 412.
In the message processing step S660, the message processing unit 381 of the meter-reading meter 301 processes the message 423 and generates a response 433.
In the master key selection step S671, the master key selection unit 363 of the meter-reading meter 301 selects the master key 431 based on the stored key type information 422. The master key selection unit 363 outputs the selected master key 431 and key type information 422.
In the temporary key generation step S672, the temporary key generation unit 364 of the meter-reading meter 301 generates a temporary key 435 based on the master key 431 and the generation number 432. The temporary key 435 generated by the temporary key generation unit 364 in the temporary key generation step S672 is the same as the temporary key 435 generated by the temporary key generation unit 364 in the temporary key generation step S655.
In the encryption step S673, the encryption unit 392 of the meter-reading meter 301 encrypts the response 433 using the temporary key 435 generated by the temporary key generation unit 364 in the temporary key generation step S672, and generates a ciphertext 436. The encryption unit 392 may be configured to encrypt the response 433 using the temporary key 435 generated by the temporary key generation unit 364 in the temporary key generation step S655. In that case, the master key selection step S671 and the temporary key generation step S672 may be omitted.
In the multiplexing step S674, the multiplexing unit 393 of the meter-reading meter 301 multiplexes the ciphertext 436, the generation number 432, and the key type information 422, and generates an encrypted response 434. The multiplexing unit 393 transmits the encryption response 434 to the mobile terminal 201 (the meter reading meter communication unit 291).
In the separation step S675, the separation unit 294 of the mobile terminal 201 receives the encryption response 434. The separation unit 294 separates the encrypted response 434 into the ciphertext 436 and the generation number 432.
In the decryption step S676, the decryption unit 295 of the mobile terminal 201 decrypts the ciphertext 436 and generates a response 433 and a verification result 427.
In the reception determination step S677, the reception determination unit 296 of the mobile terminal 201 determines whether to output the response 433 based on the generation number 432, the generation number 412, and the verification result 427. When it is determined that the response 433 is output, the reception determination unit 296 outputs the response 433 to the message generation unit 281.

The communication device (portable terminal 201, meter-reading meter 301) in this embodiment communicates using the encryption key temporarily generated in the common key encryption communication.
The communication device holds a master key shared between the devices in advance and a counter that monotonously increases over a certain period, obtains a counter value from the counter, and generates a temporary key from the master key and the counter value The message authenticator is generated for a predetermined message using the temporary key, and the counter value, the message, and the message authenticator are transmitted.

  The communication device (mobile terminal 201) acquires the temporary key and the counter value from a predetermined server (management server 101) via a public network, generates a message authenticator for a predetermined message with the temporary key, The counter value, the message, and the message authenticator are transmitted.

  The communication device (portable terminal 201, meter-reading meter 301) encrypts the message with the temporary key.

The communication device (portable terminal 201, meter-reading meter 301) receives a message transmitted by another communication device.
The communication device holds a master key shared between devices in advance and a counter that monotonously increases in a certain period, generates a temporary key from the master key and the received counter value, performs verification of the received message, If the message verification is successful and the received counter value is the same or newer than the counter value acquired from the counter, the message is accepted.

  When the received counter value is newer than the counter value acquired from the counter, the communication device (meter reading meter 301) updates the value of the previous period counter to the received counter value.

  The automatic meter reading system 801 (encryption communication system) in this embodiment generates a temporary key from a master key and a generation number and uses it for encryption. Since the generation number is updated at regular intervals, the temporary key can also be updated. Therefore, even if the key leaks from the mobile terminal, it can be invalidated after a certain period.

  The mobile terminal communication unit on the receiving side compares the sent generation number with the generation number held by itself. Therefore, even if the temporary key is leaked, the temporary key cannot be used when the generation number corresponding to the temporary key becomes invalid.

  Further, the portable terminal communication unit in the meter-reading meter succeeds in the message verification, and if the generation number held by the portable terminal is older than the sent generation number, it synchronizes the generation number to rewrite its own generation number. be able to. Since message verification is performed, even if an attacker sends an arbitrary generation number, fraud can be detected.

Embodiment 4 FIG.
The fourth embodiment will be described with reference to FIGS.
In addition, about the part which is common in Embodiment 1- Embodiment 3, the same code | symbol is attached | subjected and description is abbreviate | omitted.

  FIG. 20 is a system configuration diagram showing an example of the overall configuration of the cryptographic communication system 800 in this embodiment.

The cryptographic communication system 800 includes a plurality of cryptographic communication devices 500. The plurality of cryptographic communication devices 500 perform cryptographic communication with each other.
The hardware configuration of the cryptographic communication device 500 is the same as, for example, the management device 100, the cryptographic communication device 200, and the cryptographic communication device 300 described in the first embodiment.

  FIG. 21 is a system configuration diagram showing an example of the overall configuration of the cryptographic communication device 500 according to this embodiment.

  The cryptographic communication device 500 includes, for example, a management unit 102, a communication unit 202, and a verification unit 302.

The management unit 102 (management device) manages a master key and temporary key generation data, and generates a temporary key.
The management unit 102 includes, for example, a master key storage unit 110, a temporary key generation data storage unit 130, a temporary key generation data update unit 140, and a temporary key generation unit 160.
The master key storage unit 110 uses the storage device 914 to store a master key. In the plurality of cryptographic communication devices 500, the master keys stored in the master key storage unit 110 are all the same.
The temporary key generation data storage unit 130 uses the storage device 914 to store temporary key generation data. In the plurality of cryptographic communication devices 500, the temporary key generation data stored in the temporary key generation data storage unit 130 is not necessarily the same.
Using the processing device 911, the temporary key generation data update unit 140 repeatedly updates the temporary key generation data stored in the temporary key generation data storage unit 130 every time a predetermined period elapses.
The temporary key generation unit 160 generates a temporary key using the processing device 911. The temporary key generation unit 160 generates a temporary key using the master key stored in the master key storage unit 110 and the temporary key generation data stored in the temporary key generation data storage unit 130.

The communication unit 202 (first cryptographic communication device) notifies the other cryptographic communication device 500 of temporary key generation data used by the management unit 102 to generate a temporary key, and the management unit 102 generates the temporary key generation data. Cryptographic communication is performed with another cryptographic communication device 500 using the temporary key.
The communication unit 202 includes, for example, a temporary key generation data notification unit 250 and an encryption communication unit 290.
The temporary key generation data notification unit 250 notifies the other encryption communication apparatus 500 of the temporary key generation data stored in the temporary key generation data storage unit 130. For example, the temporary key generation data notifying unit 250 transmits the temporary key generation data to the other encryption communication device 500 using the communication device 915.
The cryptographic communication unit 290 performs cryptographic communication with another cryptographic communication device 500 using the temporary key generated by the temporary key generation unit 160. For example, the cryptographic communication unit 290 uses the processing device 911 to generate a ciphertext that is encrypted using the temporary key generated by the temporary key generation unit 160, and uses the communication device 915 to generate another encrypted communication device 500. Send to. Alternatively, the cryptographic communication unit 290 receives the ciphertext transmitted by the other cryptographic communication device 500 using the communication device 915 and uses the temporary key generated by the temporary key generation unit 160 using the processing device 911. Decrypt the received ciphertext.

The verification unit 302 verifies the temporary key generation data notified from the other cryptographic communication device 500.
The verification unit 302 includes, for example, a temporary key generation data acquisition unit 320 and a temporary key generation data verification unit 350.
The temporary key generation data acquisition unit 320 acquires temporary key generation data notified from the other encryption communication device 500. For example, the temporary key generation data acquisition unit 320 uses the communication device 915 to receive temporary key generation data transmitted by another encryption communication device 500.
The temporary key generation data verification unit 350 uses the processing device 911 to determine whether or not the temporary key generation data acquired by the temporary key generation data acquisition unit 320 is valid. The temporary key generation data verification unit 350 uses the temporary key generation data (verification data) stored in the temporary key generation data storage unit 130 (verification data storage unit). It is determined whether the temporary key generation data acquired by is valid.

The temporary key generation data verification unit 350 compares the temporary key generation data stored in the temporary key generation data storage unit 130 with the temporary key generation data acquired by the temporary key generation data acquisition unit 320. Determine which is newer.
When the temporary key generation data acquired by the temporary key generation data acquisition unit 320 is older than the temporary key generation data stored in the temporary key generation data storage unit 130, the temporary key generation data verification unit 350 It is determined that the temporary key generation data acquired by the generation data acquisition unit 320 is not valid.
When the temporary key generation data acquired by the temporary key generation data acquisition unit 320 is newer than the temporary key generation data stored in the temporary key generation data storage unit 130, the temporary key generation data verification unit 350 It is determined that the temporary key generation data acquired by the generation data acquisition unit 320 is valid.
In addition, even when the temporary key generation data acquired by and the temporary key generation data stored in the temporary key generation data storage unit 130 are the same new, the temporary key generation data verification unit 350 It is determined that the temporary key generation data acquired by the generation data acquisition unit 320 is valid.

For example, the temporary key generation data is data representing a numerical value, and the temporary key generation data update unit 140 (verification data update unit) performs the temporary key generation data storage unit 130 every time a predetermined period elapses. Is calculated by adding a predetermined incremental value to the numerical value represented by the temporary key generation data stored. The temporary key generation data update unit 140 updates the temporary key generation data stored in the temporary key generation data storage unit 130 with data representing the calculated sum. The temporary key generation data storage unit 130 stores updated new temporary key generation data in place of the old temporary key generation data stored so far. In the plurality of cryptographic communication devices 500, if the speeds at which the numerical values represented by the temporary key generation data increase are substantially the same, the cycle or temporary key generation cycle in which the temporary key generation data update unit 140 updates the temporary key generation data The increment value added to the numerical value represented by the business data is not necessarily the same.
Temporary key generation data verification unit 350 includes a numerical value represented by temporary key generation data acquired by temporary key generation data acquisition unit 320 and a numerical value represented by temporary key generation data stored by temporary key generation data storage unit 130. And the larger value is judged to be newer.

When the temporary key generation data verification unit 350 determines that the temporary key generation data acquired by the temporary key generation data acquisition unit 320 is valid, the temporary key generation data storage unit 130 stores the data thus far. Instead of the old temporary key generation data, the temporary key generation data determined by the temporary key generation data verification unit 350 to be valid is stored.
The temporary key generation unit 160 generates a temporary key based on the updated temporary key generation data. The encryption communication unit 290 uses the temporary key generated by the temporary key generation unit 160 based on the updated temporary key generation data, and communicates with another encryption communication device 500 that has notified the temporary key generation data. Encrypt communication.

  Next, the operation will be described.

The processes in the cryptographic communication system 800 are roughly classified into an initialization process S601, an update process S602, and a cryptographic communication process S604.
In the initialization process S601, the cryptographic communication device 500 initializes a master key, temporary key generation data, and the like.
In the update process S602, the cryptographic communication device 500 periodically updates the temporary key generation data.
In cryptographic communication processing S604, the cryptographic communication device 500 agrees with another cryptographic communication device 500 on a temporary key used for cryptographic communication, and performs cryptographic communication.

  FIG. 22 is a flowchart showing an example of the flow of the initialization process S601 in this embodiment.

  In the initialization process S601, the cryptographic communication device 500 executes, for example, a master key storage step S611 and a temporary key generation data initialization step S612. Note that the timings at which the plurality of cryptographic communication devices 500 execute the initialization process S601 need not be the same.

  In the master key storage step S611, the master key storage unit 110 of the encryption communication device 500 acquires a master key. The master key storage unit 110 uses the storage device 914 to store the acquired master key.

  In the temporary key generation data initialization step S612, the temporary key generation data storage unit 130 of the cryptographic communication device 500 initializes the temporary key generation data.

  FIG. 23 is a flowchart showing an example of the flow of the update process S602 in this embodiment.

  In the update process S602, the cryptographic communication device 500 executes, for example, a period elapsed determination process S613 and a temporary key generation data update process S614.

In the cycle elapse determination step S613, the temporary key generation data update unit 140 of the cryptographic communication device 500 determines whether or not a predetermined update cycle has elapsed.
If it is determined that the update cycle has elapsed, the temporary key generation data update unit 140 proceeds to the temporary key generation data update step S614.

In the temporary key generation data update step S614, the temporary key generation data update unit 140 of the cryptographic communication device 500 updates the temporary key generation data.
Thereafter, the temporary key generation data update unit 140 returns the process to the cycle elapse determination step S613 and waits for the next update cycle to elapse.

  The temporary key generation data update unit 140 may be configured to determine whether or not the update cycle has elapsed from the previous update time by the temporary key generation data update unit 140. If the temporary key generation data storage unit 130 stores the temporary key generation data determined by the temporary key generation data verification unit 350 to be valid after the update, has the update cycle elapsed since that point? It may be configured to determine whether or not.

  FIG. 24 is a flowchart showing an example of the flow of the cryptographic communication processing S604 in this embodiment.

The cryptographic communication device 500 on the side that actively starts cryptographic communication (hereinafter referred to as “calling side”) includes a temporary key generation step S616, a temporary key generation data notification step S624, and a cryptographic communication process S604. A temporary key generation data acquisition step S635b, a temporary key generation data verification step S636b, a temporary key generation step S637b, and an encryption communication step S625 are executed.
In response to a request from the calling-side encryption communication device 500, the encryption communication device 500 on the side that passively performs encryption communication (hereinafter referred to as “incoming call side”) generates a temporary key in encryption communication processing S 604. A data acquisition step S635, a temporary key generation data verification step S636, a temporary key generation step S616b, a temporary key generation data notification step S624b, a temporary key generation step S637, and an encryption communication step S638 are executed.

  In the temporary key generation step S616, the temporary key generation unit 160 of the calling-side cryptographic communication device 500 generates the master key stored in the master key storage unit 110 and the temporary key generation data stored in the temporary key generation data storage unit 130. Based on the data, a temporary key is generated.

In the temporary key generation data notification step S624, the temporary key generation data notification unit 250 of the calling-side encryption communication device 500 is the temporary key used by the temporary key generation unit 160 to generate a temporary key in the temporary key generation step S616. The generation data is notified to the encryption communication device 500 on the called side.
In the temporary key generation data acquisition step S635, the temporary key generation data acquisition unit 320 of the called encryption communication device 500 acquires the temporary key notified from the calling encryption communication device 500.

In the temporary key generation data verification step S636, the temporary key generation data verification unit 350 of the called-side encryption communication device 500 temporarily stores the temporary key generation data stored in the temporary key generation data storage unit 130 based on the temporary key generation data. It is determined whether or not the temporary key generation data acquired by the temporary key generation data acquisition unit 320 in the key generation data acquisition step S635 is valid.
If the temporary key generation data verification unit 350 determines that the temporary key generation data is valid, the temporary key generation data storage unit 130 of the called-side encryption communication device 500 determines that the temporary key generation data is valid. The temporary key generation data determined by the data verification unit 350 is stored as new temporary key generation data. The called-side encryption communication device 500 proceeds to the temporary key generation step S637.
When the temporary key generation data verification unit 350 determines that the temporary key generation data is not valid, the called-side encryption communication device 500 updates the temporary key generation data stored in the temporary key generation data storage unit 130. Without proceeding, the process proceeds to the temporary key generation step S616b.

In the temporary key generation step S637, the temporary key generation unit 160 of the called-side encryption communication device 500 stores the master key stored in the master key storage unit 110 and the temporary key generation data verification step S636. The unit 130 generates a temporary key based on the temporary key generation data newly stored. The temporary key generated by the temporary key generation unit 160 of the called-side encryption communication device 500 in the temporary key generation step S637 is generated by the temporary key generation unit 160 of the calling-side encryption communication device 500 in the temporary key generation step S616. The temporary key is the same as or corresponding to the temporary key.
The called-side encryption communication device 500 proceeds to the encryption communication step S638.

  In the temporary key generation step S616b, the temporary key generation unit 160 of the called-side encryption communication device 500 includes the master key stored in the master key storage unit 110 and the temporary key originally stored in the temporary key generation data storage unit 130. A temporary key is generated based on the key generation data.

In the temporary key generation data notification step S624b, the temporary key generation data notification unit 250 of the called-side encryption communication device 500 uses the temporary key used by the temporary key generation unit 160 to generate a temporary key in the temporary key generation step S616b. The generation data is notified to the encryption communication device 500 on the calling side.
When the temporary key generation data is notified from the called-side encryption communication device 500, the calling-side encryption communication device 500 proceeds to the temporary key generation data acquisition step S635b.
In the temporary key generation data acquisition step S635b, the temporary key generation data acquisition unit 320 of the calling-side encryption communication device 500 acquires the temporary key generation data notified from the called-side encryption communication device 500.

In the temporary key generation data verification step S636b, the temporary key generation data verification unit 350 of the calling-side encryption communication device 500 performs a temporary key generation based on the temporary key generation data stored in the temporary key generation data storage unit 130. It is determined whether or not the temporary key generation data acquired by the temporary key generation data acquisition unit 320 in the key generation data acquisition step S635b is valid.
When the temporary key generation data verification unit 350 determines that the temporary key generation data is not valid, both the encryption communication devices 500 have determined that the other party's temporary key generation data is not valid, and thus the encryption communication is started. I can't. For this reason, encryption communication processing S604 is complete | finished.
When the temporary key generation data verification unit 350 determines that the temporary key generation data is valid, the temporary key generation data storage unit 130 of the calling-side encryption communication device 500 determines that the temporary key generation data is valid. The temporary key generation data determined by the data verification unit 350 is stored as new temporary key generation data.

  In the temporary key generation step S637b, the temporary key generation unit 160 of the calling-side encryption communication device 500 stores the master key stored in the master key storage unit 110 and the temporary key generation data storage in the temporary key generation data verification step S636b. The unit 130 generates a temporary key based on the temporary key generation data newly stored. The temporary key generated by the temporary key generation unit 160 of the calling-side encryption communication device 500 in the temporary key generation step S637b is generated by the temporary key generation unit 160 of the called-side encryption communication device 500 in the temporary key generation step S616. The temporary key is the same as or corresponding to the temporary key.

In the encryption communication step S625, the encryption communication unit 290 of the caller-side encryption communication device 500 uses the temporary key generated by the temporary key generation unit 160 in the temporary key generation step S616 (or temporary key generation step S637b) to receive the call. Cryptographic communication is performed with the cryptographic communication apparatus 500 on the call side.
In the encryption communication step S638, the encryption communication unit 290 of the called-side encryption communication device 500 uses the temporary key generated by the temporary key generation unit 160 in the temporary key generation step S637 (or temporary key generation step S616b). Cryptographic communication is performed with the cryptographic communication apparatus 500 on the call side.

  As described above, a single device (encrypted communication device 500) has the functions of the three devices (the management device 100, the encrypted communication device 200, and the encrypted communication device 300) described in the first embodiment. The devices 500 can perform cryptographic communication with each other. Note that the temporary key generation data in this embodiment has both a role as temporary key generation data and a role as verification data in the first embodiment. For this reason, the cryptographic communication apparatus 500 does not need to include the verification data storage unit 330 and the verification data update unit 340 described in the first embodiment.

If the time of the clock of the calling-side encryption communication device 500 is different from the way of the clock of the called-side encryption communication device 500, if the way of the calling-side clock is faster, Since the speed at which the numerical value represented by the temporary key generation data increases is faster than that of the called side, the incoming side temporary key generation data verification unit 350 determines that the temporary key generation data on the calling side is valid. , Temporary key generation data is unified to the calling side and encrypted communication is performed.
On the other hand, if the incoming side clock is faster, the incoming side temporary key generation data verification unit 350 may determine that the outgoing side temporary key generation data is not valid. In that case, the temporary key generation data is notified from the callee side to the caller side, and the temporary key generation data is unified to the callee side to perform encrypted communication.
In this way, every time the cryptographic communication devices 500 perform cryptographic communication, the temporary key generation data is unified so that the clock advances faster.

  The temporary key generation data verification unit 350 determines that the temporary key generation data acquired by the temporary key generation data acquisition unit 320 is older than the temporary key generation data stored in the temporary key generation data storage unit 130. However, when the difference is within a predetermined range, the configuration may be such that the temporary key generation data acquired by the temporary key generation data acquisition unit 320 is valid. In this case, the temporary key generation data storage unit 130 may be configured not to update the stored temporary key generation data.

Embodiment 5. FIG.
The fifth embodiment will be described with reference to FIGS.
In addition, about the part which is common in Embodiment 1- Embodiment 4, the same code | symbol is attached | subjected and description is abbreviate | omitted.

  FIG. 25 is a diagram showing an example of the overall configuration of the automatic meter reading system 801 in this embodiment.

The automatic meter reading system 801 includes a management server 101, a portable terminal 201, and a plurality of meter reading meters 301. A plurality of portable terminals 201 may exist.
The meter-reading meter 301 not only performs cryptographic communication with the portable terminal 201, but also performs cryptographic communication between the meter-reading meters 301 using the wireless network 802. At this time, the meter-reading meter 301 does not need to communicate with the management server 101.

  The hardware configuration of the management server 101, the portable terminal 201, and the meter-reading meter 301 and the block configuration of the management server 101 and the portable terminal 201 are the same as those in the third embodiment.

  FIG. 26 is a diagram showing an example of functional blocks of the meter-reading meter 301 in this embodiment.

  The meter-reading meter 301 further includes a counter-metering meter communication unit 371 in addition to the functional blocks described in the third embodiment. Note that the mobile terminal communication unit 391 is not shown.

The message processing unit 381 generates a message 423a for the other meter reading meter 301, sends it to the meter reading meter communication unit 371, and sends a response 433b from the other meter reading meter 301 generated by the meter reading meter communication unit 371. receive.
In addition, the message processing unit 381 processes the message 423b from the other meter reading meter 301 generated by the counter meter communication unit 371, generates a response 433a, and sends the response 433a to the meter reading unit 371.

The meter reading meter communication unit 371 receives the message 423a / response 433a from the message processing unit 381. The meter reading meter communication unit 371 receives the generation number 432a from the generation number counter 331. The meter reading meter communication unit 371 generates a temporary key using the master key 431 stored in the master key storage unit 311 and the generation number 432a. The meter reading meter communication unit 371 encrypts the message 423a / response 433a generated by the message processing unit 381 using the generated temporary key, and generates an encrypted message 424a / encrypted response 434a. The meter reading meter communication unit 371 sends the encrypted message 424a / encrypted response 434a to the other meter reading meter 301.
In addition, the meter reading meter communication unit 371 receives the encrypted message 424b / encrypted response 434b from the other meter reading meter 301. The meter reading meter communication unit 371 acquires the generation number 432a from the generation number counter 331. The meter reading meter communication unit 371 compares the generation number 432b included in the encrypted message 424b / encrypted response 434b with the generation number 432a. When the generation number 432b is the same as the generation number 432a or newer than the generation number 432a, the counter meter communication unit 371 generates a temporary key using the master key 431 stored in the master key storage unit 311 and the generation number 432b. To do. The meter reading meter communication unit 371 uses the generated temporary key to decrypt the encrypted message 424b / encrypted response 434b and generate a message 423b / response 433b. The meter reading meter communication unit 371 verifies the encrypted message 424b / encrypted response 434b.
When the verification is passed, the meter reading communication unit 371 receives the encrypted message 424b / encrypted response 434b and sends the generated message 423b / response 433b to the message processing unit 381. When the generation number 432b is newer than the generation number 432a, the counter meter communication unit 371 rewrites the value of the generation number counter 331 to the generation number 432b.

  Since the details of the operation of the meter reading meter communication unit 371 in this embodiment are the same as those of the meter reading meter 301 in the third embodiment, the detailed description is omitted.

  The automatic meter reading system 801 in this embodiment uses a temporary key for encrypted communication, and can invalidate the key for a certain period. Further, generation numbers can be synchronized between devices without communication with the management server.

Embodiment 6 FIG.
The sixth embodiment will be described with reference to FIGS.
In addition, about the part which is common in Embodiment 1- Embodiment 5, the same code | symbol is attached | subjected and description is abbreviate | omitted.

  The overall configuration of the cryptographic communication system 800 in this embodiment and the hardware configuration of the management device 100 and the cryptographic communication devices 200 and 300 are the same as those in the first embodiment.

  FIG. 27 is a block configuration diagram illustrating an example of functional blocks of the management apparatus 100 according to this embodiment.

  The management device 100 further includes an initialization command generation unit 165 and an initialization command notification unit 175 in addition to the functional blocks described in the first embodiment.

  The initialization command generation unit 165 uses the processing device 911 to generate an initialization command. The initialization command is for initializing the verification data stored in the verification data storage unit 330 of the encryption communication device 300.

The initialization command generated by the initialization command generation unit 165 has an expiration date.
For example, the initialization command includes expiration date information indicating the expiration date of the initialization command. The cryptographic communication device 300 determines whether the initialization command is valid based on the expiration date information included in the initialization command.
Alternatively, the initialization command includes generation time information indicating the date and time when the initialization command generation unit 165 generated the initialization command. The cryptographic communication apparatus 300, when a predetermined period (for example, one day) has elapsed since the initialization command generation unit 165 generated the initialization command based on the generation time information included in the initialization command, Is determined to be invalid.

  Further, the initialization command generated by the initialization command generation unit 165 may be configured to include information indicating an initial value for initializing the verification data. In this case, the temporary key generation data stored in the temporary key generation data storage unit 130 may be used as the initial value of the verification data.

In addition, the initialization command generated by the initialization command generation unit 165 has a format that can be verified by the encryption communication device 300 by proving that it is generated by the management device 100.
For example, the initialization command is encrypted using the master key stored in the master key storage unit 110. The encryption communication device 300 decrypts the initialization command using the master key stored in the master key storage unit 310. If the initialization command can be decrypted correctly, it can be determined that the encrypted initialization command knows the master key, and therefore it can be determined that the management apparatus 100 has generated the initialization command.
Alternatively, the initialization command may be configured to be encrypted using a temporary key generated using the master key stored in the master key storage unit 110 and predetermined temporary key generation data. If the cryptographic communication device 300 knows the temporary key generation data used to generate the temporary key used when encrypting the initialization command, the cryptographic communication device 300 stores the master key stored in the master key storage unit 310. And a temporary key generation data known in advance, a temporary key can be generated, and an initialization command can be decrypted using the generated temporary key.
Note that the temporary key generation data used to generate a temporary key used when encrypting the initialization command may not be predetermined data. For example, the initialization command generation unit 165 randomly generates temporary key generation data to generate a temporary key, encrypts the generated temporary key, and unencrypted temporary key generation data May be combined to form an initialization command. Alternatively, the initialization command generation unit 165 generates a temporary key using the initial value of the verification data as temporary key generation data, the encrypted part using the generated temporary key, and the unencrypted verification key A configuration in which the initial value of data is combined to form an initialization command may be used. If the initialization command includes unencrypted temporary key generation data and a portion encrypted with the temporary key generated using the temporary key generation data, the encrypted portion Data including data for temporary key generation may be encrypted.

  The initialization command notification unit 175 notifies the encryption communication device 200 of the initialization command generated by the initialization command generation unit 165. For example, the initialization command notification unit 175 transmits the initialization command generated by the initialization command generation unit 165 to the encryption communication device 200 using the communication device 915.

  FIG. 28 is a block configuration diagram illustrating an example of functional blocks of the cryptographic communication device 200 according to this embodiment.

  In addition to the functional blocks described in the first embodiment, the cryptographic communication apparatus 200 further includes an initialization command acquisition unit 265, an initialization command storage unit 275, and an initialization command notification unit 285.

The initialization command acquisition unit 265 acquires the initialization command notified from the initialization command notification unit 175 of the management apparatus 100. For example, the initialization command acquisition unit 265 receives the initialization command transmitted by the initialization command notification unit 175 using the communication device 915.
The initialization command storage unit 275 stores the initialization command acquired by the initialization command acquisition unit 265 using the storage device 914.

The initialization command notification unit 285 notifies the encryption communication device 300 of the initialization command stored in the initialization command storage unit 275. For example, the initialization command notification unit 285 transmits an initialization command to the encryption communication device 300 using the communication device 915.
The initialization command notification unit 285 notifies the encryption communication device 300 of the initialization command, for example, if the temporary key generation data notified by the temporary key generation data notification unit 250 is not valid. This is a case where the temporary key generation data verification unit 350 makes a determination and the encryption communication cannot be started. In this case, it is considered that the verification data stored in the verification data storage unit 330 of the encryption communication device 300 is out of order due to some abnormality. Therefore, the verification data stored in the verification data storage unit 330 of the cryptographic communication device 300 is initialized by notifying the cryptographic communication device 300 of an initialization command.

  FIG. 29 is a block configuration diagram illustrating an example of functional blocks of the cryptographic communication device 300 according to this embodiment.

  In addition to the functional blocks described in the first embodiment, the cryptographic communication apparatus 300 further includes an initialization command acquisition unit 365 and an initialization command verification unit 375.

  The initialization command acquisition unit 365 acquires the initialization command notified from the initialization command storage unit 275 of the encryption communication device 200. For example, the initialization command acquisition unit 365 receives the initialization command transmitted from the initialization command notification unit 285 using the communication device 915.

  The initialization command verification unit 375 uses the processing device 911 to verify whether or not the initialization command acquired by the initialization command acquisition unit 365 is valid. The initialization command verification unit 375 determines the validity of the initialization command from the two points that the initialization command is a valid one generated by the management apparatus 100 and that the expiration date has not expired. .

For example, the initialization command verification unit 375 generates a temporary key using the master key stored in the master key storage unit 310 and predetermined temporary key generation data. The initialization command verification unit 375 decrypts the initialization command acquired by the initialization command acquisition unit 365 using the generated temporary key. If the initialization command is correctly decoded, the initialization command verification unit 375 determines that the initialization command is valid.
Alternatively, the initialization command verification unit 375 separates the initialization command acquired by the initialization command acquisition unit 365 into an encrypted part and temporary key generation data, and stores the master key stored in the master key storage unit 310. A temporary key is generated using the separated temporary key generation data. The initialization command verification unit 375 decrypts the separated encrypted part using the generated temporary key. The initialization command verification unit 375 acquires temporary key generation data from the decrypted result. When the separated temporary key generation data matches the acquired temporary key generation data, the initialization command verification unit 375 determines that the initialization command is valid.

Further, for example, the initialization command verification unit 375 acquires the expiration date information from the initialization command acquired by the initialization command acquisition unit 365. The initialization command verification unit 375 compares the expiration date represented by the acquired expiration date information with the current time, and determines whether or not the expiration date has expired.
Alternatively, the initialization command verification unit 375 acquires generation time information indicating the date when the initialization command was generated from the initialization command acquired by the initialization command acquisition unit 365. The initialization command verification unit 375 calculates a date a predetermined number of days before the current date, and compares the calculated date with the date represented by the generation time information. If the date represented by the generation time information is equal to or newer than the calculated date, the initialization command verification unit 375 determines that the initialization command is within the expiration date.
Alternatively, the initialization command verification unit 375 acquires generation time information indicating the time when the initialization command is generated from the initialization command acquired by the initialization command acquisition unit 365. The initialization command verification unit 375 calculates the elapsed time since the initialization command was generated based on the current time and the time represented by the generated generation time information. When the calculated elapsed time is shorter than the predetermined valid period, the initialization command verification unit 375 determines that the initialization command is within the valid period.

When the initialization command verification unit 375 determines that the initialization command acquired by the initialization command acquisition unit 365 is valid, the verification data storage unit 330 initializes the stored verification data.
For example, the verification data storage unit 330 uses the storage device 914 to store a predetermined initial value as verification data.
Alternatively, the verification data storage unit 330 uses the processing device 911 to acquire the initial value of the verification data from the initialization command determined by the initialization command verification unit 375 to be valid, and the acquired initial value Store as verification data.

  FIG. 30 is a flowchart showing an example of the flow of the temporary key notification processing S603 in this embodiment.

In the temporary key notification process S603, the management apparatus 100 further executes an initialization command generation step S617 and an initialization command notification step S620 in addition to the steps described in the first embodiment.
In addition to the process described in the first embodiment, the cryptographic communication apparatus 200 further executes an initialization command acquisition process S628 in the temporary key notification process S603.

  In the initialization command generation step S617, the initialization command generation unit 165 of the management device 100 generates an initialization command. For example, the initialization command generation unit 165 generates an initialization command including the temporary key generation data used by the temporary key generation unit 160 for generating the temporary key in the temporary key generation step S616 as the initial value of the verification data. .

In the initialization command notification step S620, the initialization command notification unit 175 of the management device 100 notifies the encryption communication device 200 of the initialization command generated by the initialization command generation unit 165 in the initialization command generation step S617. The management apparatus 100 may be configured to transmit the initialization command together with the temporary key and temporary key generation data.
In the initialization command acquisition step S628, the initialization command acquisition unit 265 of the encryption communication device 200 acquires the initialization command notified by the initialization command notification unit 175 of the management device 100 in the initialization command notification step S620. The initialization command storage unit 275 stores the initialization command acquired by the initialization command acquisition unit 265 using the storage device 914.

  Note that the management apparatus 100 does not notify the encryption communication apparatus 200 of an initialization command together with the temporary key and temporary key generation data as a response to the temporary key request from the encryption communication apparatus 200, but instead of notifying the encryption communication apparatus 200. In addition to the temporary key request, an initialization command request for requesting an initialization command may be received, and the initialization command may be notified as a response thereto.

  FIG. 31 is a flowchart showing an example of the flow of the cryptographic communication processing S604 in this embodiment.

In addition to the steps described in the first embodiment, the cryptographic communication device 200 further executes a rejection acquisition step S626 and an initialization command notification step S629 in the cryptographic communication process S604.
In addition to the steps described in the first embodiment, the cryptographic communication device 300 further executes a rejection notification step S647, an initialization command acquisition step S648, and an initialization command verification step S649 in the cryptographic communication processing S604. .

  If the temporary key generation data acquired by the temporary key generation data acquisition unit 320 of the encryption communication device 300 in the temporary key generation data acquisition step S635 is not valid, the temporary communication of the encryption communication device 300 is temporarily performed in the temporary key generation data verification step S636. When the key generation data verification unit 350 determines, the temporary key generation data verification unit 350 proceeds to the rejection notification step S647.

In the rejection notification step S647, the temporary key generation data verification unit 350 of the cryptographic communication device 300 informs the cryptographic communication device 200 that the cryptographic communication with the temporary key generated using the notified temporary key generation data is rejected. To notify. For example, the temporary key generation data verification unit 350 uses the communication device 915 to transmit a rejection message indicating that to the encryption communication device 200.
In the rejection acquisition step S626, the temporary key generation data notification unit 250 of the cryptographic communication device 200 acquires the notification in the rejection notification step S647. For example, the temporary key generation data notification unit 250 uses the communication device 915 to receive the rejection message transmitted by the temporary key generation data verification unit 350 of the encryption communication device 300.

In the initialization command notification step S629, the initialization command notification unit 285 of the encryption communication device 200 notifies the encryption communication device 300 of the initialization command stored in the initialization command storage unit 275.
In the initialization command acquisition step S648, the initialization command acquisition unit 365 of the encryption communication device 300 acquires the initialization command notified by the initialization command notification unit 285 of the encryption communication device 200 in the initialization command notification step S629.

In the initialization command verification step S649, the initialization command verification unit 375 of the cryptographic communication device 300 determines whether the initialization command acquired by the initialization command acquisition unit 365 in the initialization command acquisition step S648 is valid. .
For example, the initialization command verification unit 375 determines whether or not the initialization command is valid.
If it is determined that the initialization command is not valid, the initialization command verification unit 375 determines that the initialization command is not valid, and ends the encryption communication process S604.
If it is determined that the initialization command is valid, the initialization command verification unit 375 determines whether the validity period of the initialization command has expired.
When it is determined that the validity period of the initialization command has expired, the initialization command verification unit 375 determines that the initialization command is not valid, and ends the encryption communication process S604.
When it is determined that the validity period of the initialization command has not expired, the initialization command verification unit 375 acquires the initial value of the verification data from the initialization command. When the initialization command verification unit 375 initializes the verification data stored in the verification data storage unit 330 with the initial value of the acquired verification data, the initialization command verification unit 375 generates the temporary key in the temporary key generation data acquisition step S635. The temporary key generation data verification unit 350 determines whether or not the temporary key generation data acquired by the data acquisition unit 320 is valid.
If the temporary key generation data is not valid even after the verification data is initialized, the initialization command verification unit 375 determines that the initialization command is not valid, and ends the cryptographic communication process S604.
If the temporary key generation data becomes valid if the verification data is initialized, the initialization command verification unit 375 determines that the initialization command is valid. The verification data storage unit 330 uses the storage device 914 to store the initial value included in the initialization command as verification data. The initialization command verification unit 375 advances the processing to the temporary key generation step S637.

  Note that the initialization command verification unit 375 has a valid initialization command and the expiration date has not expired regardless of whether or not the temporary key generation data becomes valid if the verification data is initialized. In such a case, it may be configured to determine that the initialization command is valid. In this case, after the verification data stored in the verification data storage unit 330 is initialized, the validity of the temporary key generation data acquired by the temporary key generation data acquisition unit 320 is expressed as the temporary key generation data verification unit 350. Determine again. Alternatively, the encryption communication processing S604 may be once terminated, and the encryption communication apparatus 200 may retransmit the temporary key generation data to the encryption communication apparatus 300.

  The management apparatus 100 gives the authority to initialize the verification data stored in the encryption communication apparatus 300 to the encryption communication apparatus 200 by notifying the encryption communication apparatus 200 of an initialization command. Thereby, the verification data stored in the cryptographic communication device 300 can be initialized by the cryptographic communication device 200. Therefore, even if the verification data becomes an abnormal value for some reason, the verification data is returned to the normal value, Cryptographic communication can be performed between the cryptographic communication device 200 and the cryptographic communication device 300.

  Since the initialization command has an expiration date, when the expiration date has passed, the verification data stored in the encryption communication device 300 cannot be initialized by the initialization command. Thereby, for example, even when the initialization command is leaked, such as when the encryption communication device 200 is lost and the third party picks up, the third party abuses the initialization command and the encryption communication device 300 stores the initialization command. It is possible to initialize the verification data being used and prevent information from leaking from the encryption communication device 300.

Embodiment 7 FIG.
The seventh embodiment will be described with reference to FIGS.
In addition, about the part which is common in Embodiment 1- Embodiment 6, the same code | symbol is attached | subjected and description is abbreviate | omitted.

  The overall configuration of the cryptographic communication system 800 and the hardware configuration of the management device 100 and the cryptographic communication devices 200 and 300 in this embodiment are the same as those in the sixth embodiment.

  FIG. 32 is a block configuration diagram illustrating an example of functional blocks of the cryptographic communication device 200 according to this embodiment.

The cryptographic communication apparatus 200 does not have the initialization command storage unit 275 among the functional blocks described in the sixth embodiment. That is, the encryption communication device 200 does not store the initialization command.
When the initialization command notification unit 285 needs to notify the encryption communication device 300 of an initialization command, the initialization command acquisition unit 265 communicates with the management device 100 to acquire the initialization command. The initialization command notification unit 285 notifies the encryption communication device 300 of the initialization command acquired by the initialization command acquisition unit 265.

  Since the block configurations of the management device 100 and the cryptographic communication device 300 are the same as those in the sixth embodiment, only different parts will be described.

In the cryptographic communication apparatus 300, the temporary key generation data verification unit 350 indicates that the numerical value represented by the temporary key generation data acquired by the temporary key generation data acquisition unit 320 is the verification data stored in the verification data storage unit 330. If it is greater than or equal to the numerical value to be represented, it is determined that the temporary key generation data is valid.
However, when the initialization command verification unit 375 determines that the initialization command acquired by the initialization command acquisition unit 365 is valid, and the verification data stored in the verification data storage unit 330 is initialized, the temporary key The data verification unit 350 for generation includes a numerical value represented by the temporary key generation data and a numerical value represented by the verification data until a predetermined period (for example, one day) elapses after the verification data is initialized. Only when they are equal, it is determined that the temporary key generation data is valid. When the numerical value represented by the temporary key generation data is larger than the numerical value represented by the verification data, the temporary key generation data verification unit 350 determines that the temporary key generation data is not valid.

  Next, the operation will be described.

  The steps in temporary key notification processing S603 are the same as those in the first embodiment. That is, in the temporary key notification process S603, the management apparatus 100 does not generate an initialization command and does not notify the encryption communication apparatus 200 of the initialization command.

  FIG. 33 is a flowchart showing an example of the flow of the cryptographic communication processing S604 in this embodiment.

In the cryptographic communication process S604, the cryptographic communication apparatus 200 further executes an initialization command request step S627 and an initialization command acquisition step S628 in addition to the steps described in the sixth embodiment.
Note that the steps executed by the management apparatus 100 are not shown. In the encryption communication process S604, the management apparatus 100 executes an initialization command request reception step, an initialization command generation step S617, and an initialization command notification step S620.

In the initialization command request step S627, the initialization command acquisition unit 265 of the cryptographic communication device 200 requests the management device 100 for an initialization command. For example, the initialization command acquisition unit 265 uses the communication device 915 to transmit an initialization command request message for requesting an initialization command to the management device 100. The initialization command request message includes authentication information for authenticating the user of the encryption communication device 200, such as a password input by the user of the encryption communication device 200, a fingerprint of the user of the encryption communication device 200, and other biometric information. .
In the initialization command request reception step, the initialization command notification unit 175 of the management device 100 receives a request from the encryption communication device 200. For example, the initialization command notification unit 175 receives the initialization command request message transmitted from the initialization command acquisition unit 265 of the cryptographic communication device 200 using the communication device 915. The initialization command notification unit 175 verifies the authentication information included in the initialization command request message and authenticates the user of the encryption communication device 200. When the authentication fails, the management apparatus 100 does not execute the subsequent steps.

  In the initialization command generation step S617, the initialization command generation unit 165 of the management apparatus 100 includes an initialization command that includes the temporary key generation data stored in the temporary key generation data storage unit 130 as the initial value of the authentication data. Generate.

In the initialization command notification step S620, the initialization command notification unit 175 of the management device 100 notifies the encryption communication device 200 of the initialization command generated by the initialization command generation unit 165 in the initialization command generation step S617.
In the initialization command acquisition step S628, the initialization command acquisition unit 265 of the encryption communication device 200 acquires the initialization command notified by the initialization command notification unit 175 of the management device 100 in the temporary key notification step S618.

  In the initialization command notification step S629, the initialization command notification unit 285 of the encryption communication device 200 notifies the encryption communication device 300 of the initialization command acquired by the initialization command acquisition unit 265 in the initialization command acquisition step S628. .

In the initialization command verification step S649, the initialization command verification unit 375 of the cryptographic communication apparatus 300 has a valid initialization command acquired by the initialization command acquisition unit 365 in the initialization command acquisition step S648 and has an expiration date. If it is determined that it has not expired, the initial value of the verification data included in the initialization command is acquired. The initialization command verification unit 375 compares the temporary key generation data acquired by the temporary key generation data acquisition unit 320 in the temporary key generation data acquisition step S635 with the initial value of the acquired verification data.
If the temporary key generation data does not match the initial value of the verification data, the initialization command verification unit 375 determines that the initialization command is not valid, and ends the cryptographic communication process S604.
If the temporary key generation data matches the initial value of the verification data, the initialization command verification unit 375 determines that the initialization command is valid.

For example, when the cryptographic communication device 200 is small and portable, there is a possibility that a legitimate user of the cryptographic communication device 200 loses the cryptographic communication device 200 and a third party can pick it up and misuse it. However, if the temporary key stored in the cryptographic communication device 200 picked up by a third party becomes old due to the update of the verification data, the cryptographic communication device 200 performs cryptographic communication with the cryptographic communication device 300. I can't.
Further, since the initialization command is not stored in the cryptographic communication device 200, a third party cannot initialize the verification data stored in the cryptographic communication device 300.
Suppose that a third party separately obtains an initialization command by some means. The third party notifies the encryption communication device 300 of an initialization command, and tries to initialize the verification data stored in the encryption communication device 300. However, the temporary key stored in the encryption communication device 200 acquired by the third party and the temporary key generation data used for generating the temporary key and the verification command included in the initialization command obtained separately from the third party If the initial value of the business data does not match, the encrypted communication device 200 cannot perform encrypted communication with the encrypted communication device 300.
For this reason, it is possible to prevent information from leaking from the encryption communication device 300.

Embodiment 8 FIG.
An eighth embodiment will be described with reference to FIGS.
In addition, about the part which is common in Embodiment 1- Embodiment 7, the same code | symbol is attached | subjected and description is abbreviate | omitted.

  The overall configuration of the automatic meter reading system 801 (encryption communication system) in this embodiment and the hardware configurations of the management server 101, the portable terminal 201, and the meter-reading meter 301 are the same as those in the third embodiment.

  FIG. 34 is a diagram showing an example of functional blocks of the management server 101 in this embodiment.

  The management server 101 (management apparatus) further includes a clock 156 and a reset packet generation unit 166 in addition to the configuration described in the third embodiment. The key information management unit 161 is not shown.

  The clock 156 measures the current time 418. For example, the clock 156 uses the communication device 915 to communicate with the time server, and measures the accurate current time 418 by synchronizing with the time server using a mechanism such as NTP (Network Time Protocol). The clock outputs the measured current time 418.

  The reset packet generation unit 166 (initialization command generation unit) receives the reset packet issue request 428 from the portable terminal 201. The reset packet generation unit 166 acquires the generation number 412 from the generation number counter 131. The reset packet generation unit 166 acquires the current time 418 from the clock 156. The reset packet generation unit 166 generates a reset packet 419 (initialization command) for resetting the generation number 432 of the meter-reading meter 301 to the generation number 412. The reset packet generation unit 166 sends the reset packet 419 to the mobile terminal 201.

  FIG. 35 is a diagram showing an example of functional blocks of the mobile terminal 201 in this embodiment.

  Since the block configuration of the portable terminal 201 is the same as that described in the third embodiment, only different points will be described. Note that the message generation unit 281 is not shown.

The management server communication unit 221 generates a reset packet issue request 428. The management server communication unit 221 sends a reset packet issue request 428 to the management server 101 (reset packet generation unit 166).
The management server communication unit 221 receives the reset packet 419 from the management server 101 (reset packet generation unit 166).

  The meter reading meter communication unit 291 receives the reset packet 419 from the pair management server communication unit 221. The meter reading meter communication unit 291 (initialization command notification unit) sends a reset packet 419 to the meter reading meter 301.

  FIG. 36 is a diagram showing an example of functional blocks of the meter-reading meter 301 in this embodiment.

  The meter-reading meter 301 has a clock 356 in addition to the functional blocks described in the third embodiment.

  The clock 356 measures the current time 438. For example, the clock 356 uses the communication device 915 to communicate with the time server, and synchronizes with the time server using a mechanism such as NTP, thereby measuring the accurate current time 438. The clock outputs the measured current time 438.

The mobile terminal communication unit 391 (initialization command verification unit) receives the reset packet 419 from the mobile terminal 201. The mobile terminal communication unit 391 acquires the current time 438 from the clock 356. The mobile terminal communication unit 391 verifies the reset packet 419 using the clock 356 and the master key 431 stored in the master key storage unit 311. When the verification is successful, the mobile terminal communication unit 391 acquires the generation number 412 from the reset packet 419. The mobile terminal communication unit 391 sends the generation number 412 to the message processing unit 381.
The mobile terminal communication unit 391 receives the response 433 from the generation number 412. The mobile terminal communication unit 391 encrypts the response 433 and generates a reset response 439 (encrypted response). The mobile terminal communication unit 391 sends a reset response 439 to the mobile terminal 201.

  The message processing unit 381 receives the generation number 412 from the mobile terminal communication unit 391. The message processing unit 381 rewrites the value of the generation number counter 331 to the generation number 412. The message processing unit 381 generates a response 433 representing the verification result. The message processing unit 381 sends the response 433 to the portable terminal communication unit 391 (vs. meter reading communication unit 291).

  FIG. 37 is a diagram illustrating an example of detailed functional blocks of the reset packet generation unit 166 in the management server 101 of this embodiment.

  The reset packet generation unit 166 includes, for example, an authentication unit 172, a master key selection unit 173, a temporary key generation unit 174, a packet generation unit 176, and an output determination unit 177. The authentication unit 172, the master key selection unit 173, the temporary key generation unit 174, and the output determination unit 177 are the authentication unit 162, the master key selection unit 163, the temporary key generation unit 164, and the output determination unit 171 of the key information management unit 161. May be shared with the key information management unit 161.

The authentication unit 172 receives the reset packet issue request 428 from the mobile terminal 201 (to the management server communication unit 221). The authentication unit 172 determines whether or not to process the reset packet issue request 428 based on the authentication information included in the reset packet issue request 428. For example, the authentication unit 172 authenticates the sender based on the authentication information. In addition, when not authenticating, the authentication part 172 does not need to be.
When it is determined not to process the reset packet issue request 428, the authentication unit 172 outputs an output determination signal 414 indicating that the reset packet 419 is not output to the output determination unit 177.

The master key selection unit 173 arbitrarily selects the master key 411 from among the plurality of master keys 411 stored in the master key storage unit 111. For example, the master key selection unit 173 selects the master key 411 at random.
The master key selection unit 173 generates key type information 422 corresponding to the selected master key 411.

  The temporary key generation unit 174 generates a temporary key 413 based on the master key 411 selected by the master key selection unit 173 and a predetermined constant. The temporary key generation unit 174 generates a temporary key 413 using a constant instead of the generation number 412. For example, the temporary key generation unit 174 generates, as the temporary key 413, data obtained by encrypting constants with the master key 411 by a predetermined encryption method. Alternatively, the temporary key generation unit 174 generates a hash value by using a hash function with a key in which a constant and a master key 411 are input as the temporary key 413. Note that the key generation method used by the temporary key generation unit 174 to generate the temporary key 413 is that the temporary key 413 is uniquely generated from the constant and the master key 411, and the master key 411 is generated from the temporary key 413 and the constant. Must not be estimated.

  For the constant used by the temporary key generation unit 174 to generate the temporary key 413, for example, the maximum value that can be input as the generation number 412 is set. For example, when the generation number 412 is expressed in a 16-bit binary number, the temporary key generation unit 174 generates a temporary key 413 using “FFFF” as a constant in hexadecimal expression. In addition, when the maximum value of the generation number 412 is determined separately, the structure using that value may be sufficient.

  The packet generation unit 176 acquires the generation number 412 from the generation number counter 131. The packet generation unit 176 acquires the current time 418 from the clock 156 as the generation time of the reset packet 419. The packet generation unit 176 generates a message verifier for the generation number 412, generation time, key type information 422, and the constant used by the master key selection unit 173 to generate the temporary key 413. The packet generation unit 176 generates a reset packet 419 including a generation number 412, a generation time, key type information 422, a constant, and a message verifier.

The output determination unit 177 determines whether or not to output the reset packet 419 generated by the packet generation unit 176.
When the output determination signal 414 indicating that the reset packet 419 is not output is received from the authentication unit 172, the output determination unit 177 determines that the reset packet 419 is not output. In that case, the output determination unit 177 may be configured to output a predetermined error code instead of the reset packet 419.
When the output determination signal 414 indicating that the reset packet 419 is not output is not received from the authentication unit 172, the output determination unit 177 determines to output the reset packet 419. The output determination unit 177 outputs the reset packet 419 to the mobile terminal 201.

  FIG. 38 is a diagram illustrating an example of detailed functional blocks of the management server communication unit 221 and the meter reading meter communication unit 291 in the portable terminal 201 of this embodiment.

  The management server communication unit 221 further includes a reset packet issue request generation unit 224 and a reset packet acquisition unit 225 in addition to the functional blocks described in the third embodiment. The temporary key issue request generation unit 222 and the temporary key information acquisition unit 223 are not shown.

The reset packet issue request generation unit 224 receives the authentication information 425 from the input device 912. The input device 912 is a character string input device such as a keyboard, for example. Alternatively, the input device 912 is a device that acquires biometric information such as a fingerprint reader.
The reset packet issue request generator 224 generates a reset packet issue request 428 based on the acquired authentication information 425. The reset packet issue request 428 generated by the reset packet issue request generation unit 224 includes authentication information 425.
The reset packet issue request generation unit 224 sends a reset packet issue request 428 to the management server 101 (reset packet generation unit 166).
When the management server 101 does not perform user authentication, the reset packet issue request generation unit 224 may be configured not to acquire the authentication information 425. In that case, the reset packet issue request 428 may be configured not to include the authentication information 425.

  The reset packet acquisition unit 225 receives the reset packet 419 from the management server 101. The reset packet acquisition unit 225 sends the reset packet 419 to the counter meter reading unit 291.

  The meter-reading meter communication unit 291 further includes a reset packet output unit 297 in addition to the functional blocks described in the third embodiment. Note that the encryption unit 292, the multiplexing unit 293, the separation unit 294, the decryption unit 295, and the reception determination unit 296 are not shown.

  The reset packet output unit 297 receives the reset packet 419 from the management server communication unit 221. The reset packet output unit 297 sends the received reset packet 419 as it is to the meter-reading meter 301 (for the portable terminal communication unit 391).

  FIG. 39 is a diagram showing an example of detailed functional blocks of the portable terminal communication unit 391 in the meter-reading meter 301 of this embodiment.

  The mobile terminal communication unit 391 further includes a response message generation unit 397 and a message verification unit 398 in addition to the configuration described in the third embodiment. Note that the encryption unit 392 and the decryption unit 395 are not shown.

  The separation unit 394 receives the reset packet 419 from the mobile terminal 201 (the meter reading meter communication unit 291). The separation unit 394 separates the key type information 422 and the constant 417 from the reset packet 419.

  Based on the key type information 422, the master key selection unit 363 selects the master key 431 from among the plurality of master keys 431 stored in the master key storage unit 311.

  The temporary key generation unit 364 generates a temporary key 435 from the master key 431 selected by the master key selection unit 363 and the constant 417. The temporary key generation unit 364 generates a temporary key 435 by the same temporary key generation method as the temporary key generation unit 174 of the key information management unit 161 in the management server 101.

  The message verifying unit 398 verifies the message of the reset packet 419 using the temporary key 435 and generates a verification result 437. The message verification unit 398 separates the generation number 412 and the generation time 416 from the reset packet 419. The message verification unit 398 verifies the reset packet 419 using a verification method corresponding to the message authenticator generation method used by the packet generation unit 176 in the management server 101.

The reception determination unit 396 acquires the current time 438 from the clock 356. The reception determination unit 396 performs output determination based on the current time 438, the generation time 416, and the verification result 437. Judgment criteria are as follows.
When the message verification unit 398 fails in the message verification, the generation number 412 is not output.
When the generation time 416 is older than the current time 438 by a certain amount (for example, one day or more), the generation number 412 is not output.
Generation number 412 when message verification unit 398 succeeds in message verification and generation time 416 is newer than current time 438 or the difference between generation time 416 and current time 438 is less than or equal to a certain value (for example, one day or less). Is output.
When it is determined that the generation number 412 is output, the reception determination unit 396 outputs the generation number 412 to the message processing unit 381.

The message processing unit 381 receives the generation number 412 from the reception determination unit 396. The message processing unit 381 rewrites the value of the generation number counter 331 to the generation number 412.
The message processing unit 381 generates a response 433. Note that the message determination unit 396 may generate the response 433 instead of the message processing unit 381 generating the response 433.

  When the message processing unit 381 accepts the reset packet 419 and rewrites the value of the generation number counter 331, the reception determination unit 396 rewrites the value of the generation number counter 331 for a certain period (for example, one day). May be configured to accept the encrypted message 424 and output the message 423 only when the generation number 412 and the generation number 432 match.

  The response message generation unit 397 receives the response 433 from the message processing unit 381. The response message generation unit 397 generates a message authenticator 440 from the response 433 using the temporary key 435. The response message generator 397 generates the message authenticator 440 using the same message authenticator generation method as the packet generator 176 of the reset packet generator 166 in the management server 101, for example.

  The multiplexing unit 393 generates the reset response 439 by multiplexing the key type information 422, the generation number 432, the response 433, and the message authenticator 440. The multiplexing unit 393 sends a reset response 439 to the mobile terminal 201 (antimeter reading unit 291).

  Next, the operation will be described.

  FIG. 40 is a flowchart showing an exemplary flow of the reset packet notification processing S605 in this embodiment.

  The reset packet notification processing S605 includes, for example, a reset packet issue request generation step S681, an authentication step S682, a master key selection step S683, a temporary key generation step S684, a packet generation step S685, an output step S686, and a reset packet. Acquisition step S687.

In the reset packet issue request generation step S681, the reset packet issue request generation unit 224 of the mobile terminal 201 generates a reset packet issue request 428. The reset packet issue request generation unit 224 transmits a reset packet issue request 428 to the management server 101 (reset packet generation unit 166).
In the authentication step S682, the authentication unit 172 of the management server 101 receives the reset packet issue request 428. The authentication unit 172 verifies the reset packet issue request 428. If the verification fails, the authentication unit 172 ends the reset packet notification process S605. If the verification is successful, the authentication unit 172 advances the process to the master key selection step S683.
In the master key selection step S683, the master key selection unit 173 of the management server 101 arbitrarily selects the master key 411. The master key selection unit 173 generates key type information 422 corresponding to the selected master key 411.
In the temporary key generation step S684, the temporary key generation unit 174 of the management server 101 generates a temporary key 413 based on the master key 411 and the constant 417.
In the packet generation step S685, the packet generation unit 176 of the management server 101 generates the reset packet 419 from the key type information 422, the constant 417, the generation number 412 and the current time 418 using the temporary key 413. .
In the output step S686, the output determination unit 177 of the management server 101 transmits a reset packet 419 to the mobile terminal 201 (to the management server communication unit 221).
In the reset packet acquisition step S687, the reset packet acquisition unit 225 of the mobile terminal 201 receives the reset packet 419. The reset packet acquisition unit 225 outputs the reset packet 419 to the counter meter communication unit 291.

  FIG. 41 is a flowchart showing an exemplary flow of the generation number reset process S606 in this embodiment.

  The generation number reset processing S606 includes, for example, a reset packet output step S691, a separation step S692, a master key selection step S693, a temporary key generation step S694, a message verification step S695, a reception determination step S696, and a generation number reset. The process includes a step S697, a master key selection step S701, a temporary key generation step S702, a response message generation step S703, a multiplexing step S704, and a reset response acquisition step S705.

In the reset packet output step S691, the reset packet output unit 297 of the mobile terminal 201 transmits a reset packet 419 to the meter-reading meter 301 (for the mobile terminal communication unit 391).
In the separation step S692, the separation unit 394 of the meter-reading meter 301 receives the reset packet 419. The separation unit 394 separates the key type information 422 and the constant 417 from the reset packet 419.
In the master key selection step S693, the master key selection unit 363 of the meter-reading meter 301 selects the master key 431 based on the key type information 422. The master key selection unit 363 stores key type information 422.
In the temporary key generation step S694, the temporary key generation unit 364 of the meter-reading meter 301 generates a temporary key 435 based on the master key 431 and the constant 417.
In the message verification step S695, the response message generation unit 397 of the meter-reading meter 301 verifies the reset packet 419 using the temporary key 435, and generates a generation number 412, a generation time 416, and a verification result 437.
In the reception determination step S696, the reception determination unit 396 of the meter-reading meter 301 determines whether to output the generation number 412 based on the generation time 416, the current time 438, and the verification result 437. If it is determined that the generation number 412 is not output, the reception determination unit 396 ends the generation number reset process S606. When it is determined that the generation number 412 is output, the reception determination unit 396 outputs the generation number 412.
In the generation number reset step S697, the message processing unit 381 of the meter-reading meter 301 rewrites the generation number 432 stored in the generation number counter 331 with the generation number 412. The generation number counter 331 stores the generation number 412. The message processing unit 381 generates a response 433.
In the master key selection step S701, the master key selection unit 363 of the meter-reading meter 301 selects the master key 431 based on the stored key type information 422. The master key selection unit 363 outputs the selected master key 431 and key type information 422.
In the temporary key generation step S702, the temporary key generation unit 364 of the meter-reading meter 301 generates a temporary key 435 based on the master key 431 and the generation number 432. The temporary key 435 generated by the temporary key generation unit 364 in the temporary key generation step S702 is the same as the temporary key 435 generated by the temporary key generation unit 364 in the temporary key generation step S694.
In response message generation step S703, the response message generation unit 397 of the meter-reading meter 301 generates a message authenticator 440 using the temporary key 435 generated by the temporary key generation unit 364 in the temporary key generation step S672. Note that the response message generation unit 397 may be configured to generate the message authenticator 440 using the temporary key 435 generated by the temporary key generation unit 364 in the temporary key generation step S655. In that case, the master key selection step S671 and the temporary key generation step S672 may be omitted.
In the multiplexing step S704, the multiplexing unit 393 of the meter-reading meter 301 multiplexes the response 433, the message authenticator 440, the generation number 432, and the key type information 422 to generate a reset response 439. The multiplexing unit 393 transmits a reset response 439 to the portable terminal 201 (counter meter communication unit 291).
In the reset response acquisition step S705, the meter reading meter communication unit 291 of the mobile terminal 201 receives the reset response 439.

  Note that the management server 101 and the meter-reading meter 301 may directly communicate with each other, and the management server 101 may directly transmit the reset packet 419 to the meter-reading meter 301.

  The communication device (meter reading meter 301) in this embodiment receives a signal for resetting the counter value generated by the management server (101), and updates the value of the previous period counter to the counter value included in the reset signal.

The management server (101) generates a signal for resetting the counter value.
The management server generates a temporary key from a master key shared in advance and a predetermined constant, generates a message verifier for at least the counter value after correction and the generation date and time of the signal, The counter value, the signal generation date and time, and the message verifier are transmitted as a reset signal.

The communication device (meter meter 301) receives a reset signal transmitted from the management server (101).
After performing message authentication for at least the corrected counter value and signal generation date and time, the communication device compares the current time of its own clock with the generation date and time included in the reset signal, and the generation date and time is the current time. If it is newer or the difference is less than a certain value, the counter value of its own is updated to the corrected counter value.

  The automatic meter reading system 801 (encryption communication system) in this embodiment can match the generation number of the management server even if the generation number of the meter reading meter (301) is advanced from the management server (101). Further, since the date is put in the reset packet, it is possible to invalidate the old reset packet or the illegally acquired reset packet by providing the meter with a clock. Furthermore, by receiving only the same number as the generation number updated with the reset packet as a message acceptance condition for a certain period (for example, 1 day) after receiving the reset packet, it is overwritten even in the generation number updating process. Without fail, and can be synchronized reliably.

Summary.
As described above, the configuration described in each embodiment is an example, and another configuration may be used. For example, the structure which combined the structure demonstrated in different embodiment may be sufficient, and the structure which replaced the structure of the non-essential part with the other structure may be sufficient.

The encryption communication system (encryption communication system 800, automatic meter reading system 801) described above includes a management device (100, encryption communication device 500, management server 101) and a first encryption communication device (encryption communication devices 200 and 500, portable terminal). 201) and a second encryption communication device (encryption communication devices 300 and 500, meter-reading meter 301).
The management apparatus includes a master key storage unit (110, 111) and a temporary key generation unit (160, 164).
The master key storage unit of the management device stores a first master key (master key 411).
The temporary key generation unit of the management device uses the first master key stored in the master key storage unit of the management device and the temporary key generation data (generation number 412) to generate a first temporary key. (Temporary key 413) is generated.
The first cipher communication device includes a temporary key generation data notifying unit (250, meter reading meter communication unit 291) and a cipher communication unit (290, meter reading meter communication unit 291).
The temporary key generation data notifying unit of the first encryption communication device is configured to transfer the temporary key generation data used by the temporary key generation unit of the management device to generate the first temporary key to the second encryption Notify the communication device.
The cryptographic communication unit of the first cryptographic communication device performs cryptographic communication with the second cryptographic communication device using the first temporary key generated by the temporary key generation unit of the management device.
The second encryption communication device includes a master key storage unit (310, 311), a temporary key generation data verification unit (350, reception determination unit 396), a temporary key generation unit (360, 364), and an encryption communication unit. (390, portable terminal communication unit 391).
The master key storage unit of the second encryption communication device is the same as the first master key stored in the master key storage unit of the management device or corresponds to the first master key. (Master key 431) is stored.
The temporary key generation data verification unit of the second encryption communication device determines whether the temporary key generation data notified from the temporary key generation data notification unit of the first encryption communication device is valid. judge.
When the temporary key generation data notified from the temporary key generation data notifying unit of the first cryptographic communication device is valid, the temporary key generation unit of the second cryptographic communication device is valid. When the temporary key generation data verification unit determines, the second master key stored in the master key storage unit of the second encryption communication device and the temporary key generation data of the second encryption communication device The first temporary key that is the same as the first temporary key generated by the temporary key generation unit of the management device using the temporary key generation data determined to be valid by the verification unit or the first temporary key A second temporary key (temporary key 435) corresponding to is generated.
The cryptographic communication unit of the second cryptographic communication device uses the second temporary key generated by the temporary key generation unit of the second cryptographic communication device to perform cryptographic communication with the first cryptographic communication device. do.

  Since the second cryptographic communication apparatus generates a temporary key using the temporary key generation data notified from the first cryptographic communication apparatus, the first cryptographic communication apparatus and the second cryptographic communication apparatus are the same or correspond to each other. You can use the temporary key for encrypted communication.

The management device (100, encryption communication device 500, management server 101) further includes a temporary key generation data storage unit (130, generation number counter 131) and a temporary key generation data update unit (140, generation number counter 131). ).
The temporary key generation data storage unit of the management device includes temporary key generation data (temporary key generation data (160, 164) used by the management device for generating the first temporary key (temporary key 413)). The generation number 412) is stored.
The temporary key generation data update unit of the management device repeatedly updates the temporary key generation data stored in the temporary key generation data storage unit of the management device every time a predetermined period elapses.
The second encryption communication device (encryption communication devices 300 and 500, meter-reading meter 301) further includes a verification data storage unit (330, temporary key generation data storage unit 130, generation number counter 331), and verification data update. (340, temporary key generation data update unit 140, generation number counter 331).
The verification data storage unit of the second encryption communication device stores verification data (temporary key generation data, generation number 432).
The verification data update unit of the second cryptographic communication device repeatedly updates the verification data stored in the verification data storage unit of the second cryptographic communication device every time a predetermined period elapses.
The temporary key generation data verification unit of the second cryptographic communication device uses the verification data stored in the verification data storage unit of the second cryptographic communication device to use the temporary data of the first cryptographic communication device. It is determined whether or not the temporary key generation data notified from the key generation data notification unit is valid.

  Since the management device repeatedly updates the temporary key generation data and the second encryption communication device repeatedly updates the verification data accordingly, the temporary key generated from the old temporary key generation data may be invalidated. it can. Thereby, even if the first temporary key is leaked from the first cryptographic communication device, it is possible to prevent a third party from performing cryptographic communication with the second cryptographic communication device. Further, since the first cryptographic communication device does not know the first master key, the first master key is not leaked from the first cryptographic communication device. For this reason, even if information leaks from the first encryption communication device, a third party cannot generate a first temporary key that can be encrypted with the second encryption communication device.

The temporary key generation data (generation number 412) stored in the temporary key generation data storage unit (130, generation number counter 131) of the management device (100, encryption communication device 500, management server 101); The verification data (temporary) stored in the verification data storage unit (330, temporary key generation data storage unit 130, generation number counter 331) of the second encryption communication device (encryption communication device 300, 500, meter-reading meter 301). The key generation data (generation number 432) is data representing a numerical value.
The temporary key generation data update unit (140, generation number counter 131) of the management device sets a predetermined value to the numerical value represented by the temporary key generation data stored in the temporary key generation data storage unit of the management device. Is added, and the temporary key generation data stored in the temporary key generation data storage unit of the management device is updated with data representing the calculated sum.
The verification data update unit (340, temporary key generation data update unit 140, generation number counter 331) of the second cryptographic communication device is used by the temporary key generation data update unit of the management device for the temporary key generation. The verification data stored in the verification data storage unit of the second encryption communication device is stored every time a cycle approximately n times (n is a positive real number) of the predetermined cycle for updating data elapses. A sum obtained by adding an increment value n times the predetermined increment value used by the temporary key generation data updating unit of the management device to update the temporary key generation data to the numerical value to be expressed; The verification data stored in the verification data storage unit of the encryption communication device is updated with data representing the calculated sum.
The temporary key generation data verification unit (350, reception determination unit 396) of the second encryption communication device is the temporary key generation data of the first encryption communication device (encryption communication devices 200, 500, portable terminal 201). The numerical value represented by the temporary key generation data notified from the notification unit (250, counter meter communication unit 291) is represented by the verification data stored in the verification data storage unit of the second encryption communication device. If it is greater than or equal to the numerical value, it is determined that the temporary key generation data notified from the temporary key generation data notification unit of the first encryption communication device is valid.

  Thereby, it is possible to easily determine whether or not the temporary key generation data is valid.

  The verification data storage unit (330, temporary key generation data storage unit 130, generation number counter 331) of the second encryption communication device (encryption communication device 300, 500, meter-reading meter 301) is the first encryption communication device. The temporary key generation data (generation number 412) notified from the temporary key generation data notification unit (250, counter meter communication unit 291) of (encryption communication devices 200, 500, portable terminal 201) is valid. And the temporary key generation data verification unit (350, reception determination unit 396) of the second encryption communication device determines that the temporary key generation data verification unit of the second encryption communication device is valid. The determined temporary key generation data is stored as the verification data (temporary key generation data, generation number 432).

  Thereby, the temporary key generation data of the management device and the verification data of the second encryption communication device can be easily synchronized.

The management apparatus (100, management server 101) further includes an initialization command generation unit (165, reset packet generation unit 166).
The initialization command generation unit of the management device includes verification data (330, generation number counter 331) stored in the verification data storage unit (330, generation number counter 331) of the second encryption communication device (encryption communication device 300, meter-reading meter 301). An initialization command (reset packet 419) for initializing the generation number 432) is generated.
The first encryption communication device (encryption communication device 200, portable terminal 201) further includes an initialization command notification unit (285, reset packet output unit 297).
The initialization command notification unit of the first encryption communication device notifies the second encryption communication device of the initialization command generated by the initialization command generation unit of the management device.
The second cryptographic communication apparatus further includes an initialization command verification unit (375, reception determination unit 396).
The initialization command verification unit of the second encryption communication device determines whether the initialization command notified from the initialization command notification unit of the first encryption communication device is valid.
The verification data storage unit of the second cryptographic communication device may be configured such that the initialization command of the second cryptographic communication device is valid when the initialization command notified from the initialization command notification unit of the first cryptographic communication device is valid. If the verification command verification unit determines, the stored verification data is initialized.

  As a result, even if the verification data becomes an abnormal value due to some cause, the verification data can be initialized and returned to the normal value.

  The initialization command verification unit (375, reception determination unit 396) of the second encryption communication device (encryption communication device 300, meter-reading meter 301) is the same as the first encryption communication device (encryption communication device 200, portable terminal 201). The first encryption communication device when the predetermined period has not elapsed since the initialization command (reset packet 419) notified from the initialization command notification unit (285, reset packet output unit 297) has been generated It is determined that the initialization command notified from the initialization command notification unit is valid.

  This makes it possible to invalidate the old initialization command, so that even if the initialization command is leaked, a third party can misuse the initialization command to perform encrypted communication with the second encryption communication device. Can be prevented.

The initialization command (reset packet 419) generated by the initialization command generation unit (165, reset packet generation unit 166) of the management apparatus (100, management server 101) indicates the date when the initialization command was generated. Contains information to represent.
The initialization command verification unit (375, reception determination unit 396) of the second encryption communication device (encryption communication device 300, meter-reading meter 301) is the same as the first encryption communication device (encryption communication device 200, portable terminal 201). When the date represented by the information included in the initialization command notified from the initialization command notification unit (285, reset packet output unit 297) is after a predetermined number of days before the current date, It determines with the said initialization command notified from the said initialization command notification part of a 1st encryption communication apparatus being effective.

  This makes it possible to invalidate an initialization command that has passed a predetermined number of days since it was generated.

The initialization command (reset packet 419) generated by the initialization command generation unit (165, reset packet generation unit 166) of the management device (100, management server 101) is the temporary key generation data of the management device. It includes information representing the temporary key generation data (generation number 412) stored in the storage unit (130, generation number counter 131).
If the verification data storage unit (330, generation number counter 331) of the second encryption communication device (encryption communication device 300, meter-reading meter 301) is valid, the initialization command verification unit of the second encryption communication device. By storing the temporary key generation data represented by the information included in the initialization command determined by (375, reception determination unit 396) as the verification data (generation number 432), the verification data is stored. initialize.

  As a result, the temporary key generation data of the management device and the verification data of the second encryption communication device can be synchronized.

  The temporary key generation data verification unit (350, reception determination unit 396) of the second encryption communication device (encryption communication device 300, meter-reading meter 301) is the verification data storage unit (330) of the second encryption communication device. , The generation number counter 331) initializes the verification data (generation number 432) until a predetermined period elapses, the first encryption communication device (encryption communication device 200, portable terminal 201) described above. The numerical value represented by the temporary key generation data (generation number 412) notified from the temporary key generation data notification unit (250, counter meter communication unit 291) is the verification data storage of the second encryption communication device. When the first encryption communication device is equal to the numerical value represented by the verification data (generation number 432) stored in the unit (330, generation number counter 331) It is determined that the temporary key generation data notified from the generation data notification unit is valid, and the verification data storage unit of the second cryptographic communication device initializes the verification data, and After a predetermined period has elapsed since the verification data storage unit of the second cryptographic communication device has initialized the verification data, the temporary key generation data notification unit of the first cryptographic communication device is notified. When the numerical value represented by the temporary key generation data is equal to or greater than the numerical value represented by the verification data stored in the verification data storage unit of the second cryptographic communication device, the first cryptographic communication device It is determined that the temporary key generation data notified from the temporary key generation data notification unit is valid.

  As a result, only the temporary key generation data equal to the initialized verification data is accepted until the predetermined period elapses after the verification data is initialized, so that the initialization command and the temporary key are leaked. Even in this case, it is possible to prevent a third party from performing cryptographic communication with the second cryptographic communication device.

The initialization command (reset packet 419) generated by the initialization command generation unit (165, reset packet generation unit 166) of the management device (100, management server 101) is the master key storage unit ( 110, 111) includes information encrypted using the first master key (master key 411) stored.
The initialization command verification unit (375, message verification unit 398) of the second cryptographic communication device (cryptographic communication device 300, meter-reading meter 301) is the same as the first cryptographic communication device (cryptographic communication device 200, portable terminal 201). Information included in the initialization command notified from the initialization command notification unit (285, reset packet output unit 297) is stored in the master key storage unit (310, 311) of the second encryption communication device. Decrypt using the second master key (master key 431).

  Thereby, it can be verified that the person who knows the first master key has generated the initialization command.

The first encryption communication device (encryption communication device 200, portable terminal 201) is a device that is physically separated from the management device.
The management apparatus (100, management server 101) further includes a temporary key notification unit (170, output determination unit 171) and a temporary key generation data notification unit (150, output determination unit 171).
The temporary key notification unit of the management device uses the first temporary key (temporary key 413) generated by the temporary key generation unit (160, temporary key generation unit 164) of the management device as the first cryptographic communication. Notify the device.
The temporary key generation data notifying unit of the management device uses the temporary key generation data (generation number 412) used by the temporary key generation unit of the management device to generate the first temporary key. One encryption communication apparatus is notified.
The first cryptographic communication apparatus further includes a temporary key storage unit (270) and a temporary key generation data storage unit (230).
The temporary key storage unit of the first encryption communication device stores the first temporary key notified from the temporary key notification unit of the management device.
The temporary key generation data storage unit of the first encryption communication device stores the temporary key generation data notified from the temporary key generation data notification unit of the management device.
The temporary key generation data notifying unit (250, meter reading meter communication unit 291) of the first cryptographic communication device is configured to generate the temporary key stored in the temporary key generation data storage unit of the first cryptographic communication device. The data is notified to the second encryption communication device (300, meter-reading meter 301).

  Since the first encryption communication device acquires and stores the temporary key and temporary key generation data in advance, the number of times of communication with the management device can be reduced. In addition, since the first cryptographic communication device does not know the first master key, even if information leaks from the first cryptographic communication device, a third party generates a temporary key that can be encrypted with the second cryptographic communication device. Can be prevented.

  The first encryption communication device (encryption communication device 200, portable terminal 201) is portable.

  Since the first cryptographic communication device is portable, the user of the first cryptographic communication device loses the first cryptographic communication device and the information stored by the first cryptographic communication device can be leaked by a third party. There is sex. However, since the first cryptographic communication device does not know the first master key, it is possible to prevent a third party from generating a temporary key that can be cryptographically communicated with the second cryptographic communication device.

The cryptographic processing apparatus (the management apparatus 100, the cryptographic communication apparatuses 200, 300, 500, the management server 101, the portable terminal 201, and the meter-reading meter 301) described above includes a master key storage unit (110, 310, 111, 311) and a temporary And a key generation unit (160, 360, 164, 364).
The master key storage unit stores master keys (411, 431).
The temporary key generation unit generates a temporary key (413, 435) using the master key stored in the master key storage unit and the temporary key generation data (generation numbers 412 and 432).

  Since the temporary key is generated from the master key and the temporary key generation data, the temporary key used for encryption communication can be easily changed.

The cryptographic processing devices (cryptographic communication devices 300 and 500, meter-reading meter 301) further include a temporary key generation data verification unit (350, reception determination unit 396) and a cryptographic communication unit (390, portable terminal communication unit 391). And have.
In the temporary key generation data verification unit, temporary key generation data (generation numbers 412 and 432) notified from other cryptographic processing devices (encryption communication devices 200 and 500, portable terminal 201, meter-reading meter 301) are valid. It is determined whether or not there is.
When the temporary key generation data verification unit determines that the temporary key generation data notified from the other cryptographic processing device is valid, the temporary key generation unit (110, 110, 310, 111, 311) stored in the master key (411, 431) and the temporary key generation data determined by the temporary key generation data verification unit as valid, the temporary key (435) Is generated.
The cryptographic communication unit (390, mobile terminal communication unit 391) performs cryptographic communication with the other cryptographic processing device using the temporary key generated by the temporary key generation unit.

  Since the validity of the temporary key generation data notified from other cryptographic processing devices is determined and encrypted communication is performed using the temporary key generated using the temporary key generation data determined to be valid, it is easy. A temporary key used for cryptographic communication can be agreed.

The cryptographic processing devices (cryptographic communication devices 300 and 500, meter-reading meter 301) further include a temporary key generation data storage unit (130, verification data storage unit 330, generation number counter 331), and temporary key generation data update. (140, verification data update unit 340, generation number counter 331).
The temporary key generation data storage unit stores temporary key generation data (generation number 432) used by the temporary key generation unit (160, 360, 364) to generate the temporary key (413, 435).
The temporary key generation data update unit repeatedly updates the temporary key generation data stored in the temporary key generation data storage unit every time a predetermined period elapses.
The temporary key generation data verification unit (350, reception determination unit 396) uses the temporary key generation data stored in the temporary key generation data storage unit to use the other encryption processing device (encryption communication device 200). , 500, portable terminal 201, meter-reading meter 301), it is determined whether or not the temporary key generation data (generation numbers 412 and 432) is valid.

  Since the old temporary key generation data can be invalidated, even if the temporary key is leaked, it is possible to prevent a third party from performing cryptographic communication with the cryptographic processing device.

The temporary key generation data (generation number 432) stored in the temporary key generation data storage unit (130, verification data storage unit 330, generation number counter 331) is data representing a numerical value.
The temporary key generation data update unit (140, verification data update unit 340, generation number counter 331) sets a predetermined value to the numerical value represented by the temporary key generation data stored in the temporary key generation data storage unit. A sum obtained by adding the increment values is calculated, and the temporary key generation data stored in the temporary key generation data storage unit is updated with data representing the calculated sum.
The temporary key generation data verification unit (350, reception determination unit 396) receives the temporary key generation data notified from the other cryptographic processing devices (encryption communication devices 200 and 500, portable terminal 201, meter-reading meter 301). When the numerical value represented by (generation number 412) is greater than or equal to the numerical value represented by the temporary key generation data stored in the temporary key generation data storage unit, the temporary information notified from the other cryptographic processing device. It is determined that the key generation data is valid.

  Thereby, the validity of the temporary key generation data can be easily determined.

  The temporary key generation data storage unit (130, verification data storage unit 330, generation number counter 331) is notified from the other encryption processing devices (encryption communication devices 200 and 500, portable terminal 201, meter-reading meter 301). If the temporary key generation data verification unit (350, reception determination unit 396) determines that the temporary key generation data (generation numbers 412 and 432) is valid, the temporary key generation data is valid. The temporary key generation data determined by the data verification unit is stored.

  Thereby, the temporary key generation data can be easily synchronized between the cryptographic processing devices.

The cryptographic processing device (cryptographic communication device 300, meter-reading meter 301) further includes an initialization command verification unit (initialization command verification unit 375, reception determination unit 396).
The initialization command verification unit determines whether the initialization command (reset packet 419) notified from the other cryptographic processing device (encrypted communication device 200, portable terminal 201, management server 101) is valid. .
In the temporary key generation data storage unit (verification data storage unit 330, generation number counter 331), the initialization command verification unit determines that the initialization command notified from the other cryptographic processing device is valid. In this case, the stored temporary key generation data (generation number 432) is initialized.

  Thereby, even if the temporary key generation data becomes an abnormal value for some reason, the temporary key generation data can be returned to the normal value.

The cryptographic processing devices (the cryptographic communication devices 200 and 500, the portable terminal 201, and the meter-reading meter 301) further include a temporary key generation data notification unit (250, the counter-metering meter communication unit 291) and a cryptographic communication unit (290, paired meter). Meter reading meter communication units 291 and 371).
The temporary key generation data notifying unit includes the temporary key generation data (generation numbers 412 and 432) used by the temporary key generation unit (160, 164, 364) to generate the temporary key (temporary keys 413, 435). ) To other cryptographic processing devices (cryptographic communication devices 300 and 500, meter-reading meter 301).
The encryption communication unit performs encryption communication with the other encryption communication device using the temporary key generated by the temporary key generation unit.

  Since the cryptographic communication is performed using the temporary key generated using the temporary key generation data notified to the other cryptographic processing device, it is possible to easily agree the temporary key used for the cryptographic communication.

Management device (100, encryption communication device 500, management server 101), first encryption communication device (encryption communication devices 200, 500, portable terminal 201), second encryption communication device (encryption communication devices 300, 500, meter reading) described above Meter 301) and cryptographic processing device (management device 100, cryptographic communication devices 200, 300, 500, management server 101, portable terminal 201, meter-reading meter 301) can be realized by a computer executing a computer program.
According to a computer program that causes a computer to function as a management device, a first cryptographic communication device, a second cryptographic communication device, or a cryptographic processing device, it is possible to easily realize a cryptographic communication system or a cryptographic processing device that exhibits the effects described above. it can.

  For example, in the automatic meter reading system (801), the meter reading meter (301) communicates with an external device (mobile terminal 201) to communicate power information and control information. At this time, the wireless section may be communicated, and it is necessary to protect these from illegal acts such as eavesdropping. In order to protect information from fraudulent acts such as eavesdropping and tampering, an encryption communication system is used in which information is encrypted and transmitted, and decrypted and used on the receiving side.

  In an encryption communication system, it is necessary to share a key used for encryption between a sender and a receiver. In particular, when using a cipher called a common key cipher, it is necessary to prevent the shared key from leaking to the outside.

  According to the cryptographic communication system described above, the key used for encryption can be easily changed. Moreover, even if a portable terminal is lost and an unauthorized person acquires the terminal, meter reading information for all meter meters cannot be acquired.

  In addition, the counter can be easily synchronized between the client and the server. Even when the counter deviates, the deviation can be corrected, so that communication is possible even when the deviation exceeds a certain range.

  Even if the temporary key is leaked, the temporary key can be automatically invalidated after a certain period of time.

  Further, it is not necessary to completely synchronize the clock of the meter reading meter and the clock of the portable terminal. For this reason, it is not necessary to ensure the accuracy and authenticity of the time synchronization information.

According to the cryptographic communication system described above, it is possible to provide a communication device that realizes key invalidation and key synchronization while using a temporary key.
In addition, the encryption communication system demonstrated above is applicable not only to communication between the meter-reading meter and portable terminal in an automatic meter-reading system but to encryption communication of arbitrary apparatuses.

  100 management device, 101 management server, 102 management unit, 110, 111, 310, 311 master key storage unit, 130, 230 temporary key generation data storage unit, 131, 331 generation number counter, 140 temporary key generation data update unit 150, 250 Temporary key generation data notification unit, 156, 356 Clock, 160, 164, 174, 360, 364 Temporary key generation unit, 161 Key information management unit, 162, 172 Authentication unit, 163, 173, 363 Master key Selection unit, 165 Initialization command generation unit, 166 Reset packet generation unit, 170 Temporary key notification unit, 171, 177 Output determination unit, 175, 285 Initialization command notification unit, 176 packet generation unit, 200, 300, 500 Cryptographic communication Apparatus, 201 portable terminal, 202 communication unit, 220, 320 Temporary key generation data acquisition unit, 221 to management server communication unit, 222 Temporary key issue request generation unit, 223 Temporary key information acquisition unit, 224 Reset packet issue request generation unit, 225 Reset packet acquisition unit, 260 Temporary key acquisition unit, 265, 365 Initialization command acquisition unit, 270 Temporary key storage unit, 275 Initialization command storage unit, 281 Message generation unit, 290, 390 Encryption communication unit, 291, 371 Counter meter communication unit, 292, 392 Encryption unit, 293, 393 Multiplexing unit, 294, 394 Separation unit, 295, 395 Decoding unit, 296, 396 Reception determination unit, 297 Reset packet output unit, 301 Meter reading meter, 302 verification unit, 330 Verification data storage unit, 340 For verification Data update unit, 350 Temporary key generation data verification unit, 375 Initial Command verification unit, 381 message processing unit, 391 to mobile terminal communication unit, 397 response message generation unit, 398 message verification unit, 411, 431 master key, 412, 432 generation number, 413, 435 temporary key, 414 output determination signal, 416 generation time, 417 constant, 418, 438 current time, 419 reset packet, 421 temporary key issue request, 422 key type information, 423 message, 424 encrypted message, 425 authentication information, 426, 436 ciphertext, 427, 437 verification Result 428 Reset packet issue request, 433 response, 434 encryption response, 439 reset response, 440 message authenticator, 800 cryptographic communication system, 801 automatic meter reading system, 802 wireless network, 803 public network, 911 processing device, 12 input device, 913 output device, 914 storage device, 915 communication device, S601 initialization processing, S602 update processing, S603 temporary key notification processing, S604 encryption communication processing, S605 reset packet notification processing, S606 generation number reset processing, S611 S631 Master key storage step, S612 Temporary key generation data initialization step, S613, S633 Period elapsed determination step, S614 Temporary key generation data update step, S615 Temporary key request reception step, S616, S637, S644, S655, S672 S684, S694, S702 Temporary key generation step, S617 Initialization command generation step, S618 Temporary key notification step, S619, S624 Temporary key generation data notification step, S620, S629 Initialization command notification step, S621 Temporary Request Step, S622 Temporary Key Acquisition Step, S623, S635 Temporary Key Generation Data Acquisition Step, S625, S638 Encryption Communication Step, S626 Rejection Acquisition Step, S627 Initialization Command Request Step, S628, S648 Initialization Command Acquisition Step, S632 Verification Data initialization process, S634 verification data update process, S636 temporary key generation data verification process, S641 temporary key issue request generation process, S642, S682 authentication process, S643, S654, S671, S683, S693, S701 Master key selection Step, S645, S686 Output step, S646 Temporary key information acquisition step, S647 Rejection notification step, S649 Initialization command verification step, S651, S673 Encryption step, S652, S674, S704 Multiplex step, S653, S675 , S692 separation step, S656, S676 decoding step, S657, S677, S696 reception determination step, S660 message processing step, S681 reset packet issue request generation step, S685 packet generation step, S687 reset packet acquisition step, S691 reset packet output step, S695 message verification step, S697 generation number reset step, S703 response message generation step, S705 reset response acquisition step.

Claims (19)

In a cryptographic communication system comprising a management device, a first cryptographic communication device, and a second cryptographic communication device,
The management device includes a master key storage unit and a temporary key generation unit,
The master key storage unit of the management device stores a first master key,
The temporary key generation unit of the management device generates a first temporary key using the first master key stored in the master key storage unit of the management device and the temporary key generation data,
The first encryption communication device includes a temporary key generation data notification unit and an encryption communication unit,
The temporary key generation data notifying unit of the first encryption communication device is configured to transfer the temporary key generation data used by the temporary key generation unit of the management device to generate the first temporary key to the second encryption Notify the communication device,
The cryptographic communication unit of the first cryptographic communication device performs cryptographic communication with the second cryptographic communication device using the first temporary key generated by the temporary key generation unit of the management device,
The second cryptographic communication device includes a master key storage unit, a temporary key generation data verification unit, a temporary key generation unit, and an encryption communication unit,
The master key storage unit of the second encryption communication device is the same as the first master key stored in the master key storage unit of the management device or corresponds to the first master key. Remember
The temporary key generation data verification unit of the second encryption communication device determines whether the temporary key generation data notified from the temporary key generation data notification unit of the first encryption communication device is valid. Judgment,
When the temporary key generation data notified from the temporary key generation data notifying unit of the first cryptographic communication device is valid, the temporary key generation unit of the second cryptographic communication device is valid. When the temporary key generation data verification unit determines, the second master key stored in the master key storage unit of the second encryption communication device and the temporary key generation data of the second encryption communication device The first temporary key that is the same as the first temporary key generated by the temporary key generation unit of the management device using the temporary key generation data determined to be valid by the verification unit or the first temporary key Generate a second temporary key corresponding to
The cryptographic communication unit of the second cryptographic communication device uses the second temporary key generated by the temporary key generation unit of the second cryptographic communication device to perform cryptographic communication with the first cryptographic communication device. A cryptographic communication system characterized by: The management device further includes a temporary key generation data storage unit and a temporary key generation data update unit,
The temporary key generation data storage unit of the management device stores temporary key generation data used by the temporary key generation unit of the management device to generate the first temporary key,
The temporary key generation data updating unit of the management device repeatedly updates the temporary key generation data stored in the temporary key generation data storage unit of the management device every time the first period elapses. ,
The second encryption communication device further includes a verification data storage unit and a verification data update unit,
The verification data storage unit of the second encryption communication device stores verification data,
The verification data update unit of the second cryptographic communication device repeatedly updates the verification data stored in the verification data storage unit of the second cryptographic communication device every time the second period elapses. ,
The temporary key generation data verification unit of the second cryptographic communication device uses the verification data stored in the verification data storage unit of the second cryptographic communication device to use the temporary data of the first cryptographic communication device. 2. The cryptographic communication system according to claim 1, wherein it is determined whether or not the temporary key generation data notified from the key generation data notification unit is valid. The temporary key generation data stored in the temporary key generation data storage unit of the management device and the verification data stored in the verification data storage unit of the second encryption communication device are data representing numerical values. And
The temporary key generation data update unit of the management device calculates a sum obtained by adding an increment value to the numerical value represented by the temporary key generation data stored in the temporary key generation data storage unit of the management device. , Updating the temporary key generation data stored in the temporary key generation data storage unit of the management device with data representing the calculated sum,
The verification data update unit of the second cryptographic communication device has a period n times longer than the second cycle in which the temporary key generation data update unit of the management device updates the temporary key generation data. For each time, the temporary key generation data update unit of the management device updates the temporary key generation data to the numerical value represented by the verification data stored in the verification data storage unit of the second encryption communication device. The sum obtained by adding the increment value n times the increment value used in the above is calculated, and the verification data stored in the verification data storage unit of the second encryption communication device is updated with data representing the calculated sum And
The temporary key generation data verification unit of the second cryptographic communication device is configured such that the numerical value represented by the temporary key generation data notified from the temporary key generation data notification unit of the first cryptographic communication device is the first key. The temporary key notified from the temporary key generation data notifying unit of the first cryptographic communication device when the verification data stored in the verification data storage unit of the second cryptographic communication device is greater than or equal to the numerical value represented by the verification data The cryptographic communication system according to claim 2, wherein the generation data is determined to be valid.   The verification data storage unit of the second cryptographic communication device is configured to receive the second cryptographic communication when the temporary key generation data notified from the temporary key generation data notification unit of the first cryptographic communication device is valid. When the temporary key generation data verification unit of the apparatus determines, the temporary key generation data determined to be valid by the temporary key generation data verification unit of the second encryption communication device is used as the verification data. The cryptographic communication system according to claim 2, wherein the cryptographic communication system is stored as The second encryption communication device further includes a verification data storage unit,
The verification data storage unit of the second encryption communication device stores verification data,
The temporary key generation data verification unit of the second cryptographic communication device uses the verification data stored in the verification data storage unit of the second cryptographic communication device to use the temporary data of the first cryptographic communication device. Determine whether the temporary key generation data notified from the key generation data notification unit is valid,
The management apparatus further includes an initialization command generation unit,
The initialization command generation unit of the management device generates an initialization command for initializing the verification data stored in the verification data storage unit of the second encryption communication device,
The first encryption communication device further includes an initialization command notification unit,
The initialization command notification unit of the first encryption communication device notifies the initialization command generated by the initialization command generation unit of the management device to the second encryption communication device,
The second cryptographic communication device further includes an initialization command verification unit,
The initialization command verification unit of the second encryption communication device determines whether the initialization command notified from the initialization command notification unit of the first encryption communication device is valid,
The verification data storage unit of the second cryptographic communication device may be configured such that the initialization command of the second cryptographic communication device is valid when the initialization command notified from the initialization command notification unit of the first cryptographic communication device is valid. 5. The cryptographic communication system according to claim 1, wherein the verification data stored is initialized when the verification command verification unit makes a determination. The initialization command verification unit of the second encryption communication device has not passed the first period since the initialization command notified from the initialization command notification unit of the first encryption communication device is generated. In this case, it is determined that the initialization command notified from the initialization command notification unit of the first encryption communication device is valid. The initialization command generated by the initialization command generation unit of the management device includes information representing a date on which the initialization command is generated,
The initialization command verification unit of the second encryption communication device is configured such that the date represented by the information included in the initialization command notified from the initialization command notification unit of the first encryption communication device is a current date. And determining that the initialization command notified from the initialization command notifying unit of the first encryption communication device is valid when the time is after the first number of days before. The cryptographic communication system described. The management device further includes a temporary key generation data storage unit and a temporary key generation data update unit,
The temporary key generation data storage unit of the management device stores temporary key generation data used by the temporary key generation unit of the management device to generate the first temporary key,
The temporary key generation data updating unit of the management device repeatedly updates the temporary key generation data stored in the temporary key generation data storage unit of the management device every time the first period elapses. ,
The second encryption communication device further includes a verification data update unit,
The verification data update unit of the second cryptographic communication device repeatedly updates the verification data stored in the verification data storage unit of the second cryptographic communication device every time the second period elapses. ,
The initialization command generated by the initialization command generation unit of the management device includes information representing the temporary key generation data stored in the temporary key generation data storage unit of the management device,
The temporary key generation represented by the information included in the initialization command determined by the initialization command verification unit of the second cryptographic communication apparatus is valid for the verification data storage unit of the second cryptographic communication apparatus 6. The cryptographic communication system according to claim 5, wherein the verification data is initialized by storing the verification data as the verification data. The temporary key generation data stored in the temporary key generation data storage unit of the management device and the verification data stored in the verification data storage unit of the second encryption communication device are data representing numerical values. And
The temporary key generation data update unit of the management device calculates a sum obtained by adding an increment value to the numerical value represented by the temporary key generation data stored in the temporary key generation data storage unit of the management device. , Updating the temporary key generation data stored in the temporary key generation data storage unit of the management device with data representing the calculated sum,
The verification data update unit of the second cryptographic communication device has a period n times longer than the first cycle in which the temporary key generation data update unit of the management device updates the temporary key generation data. For each time, the temporary key generation data update unit of the management device updates the temporary key generation data to the numerical value represented by the verification data stored in the verification data storage unit of the second encryption communication device. The sum obtained by adding the increment value n times the increment value used in the above is calculated, and the verification data stored in the verification data storage unit of the second encryption communication device is updated with data representing the calculated sum And
The temporary key generation data verification unit of the second cryptographic communication device is a period from when the verification data storage unit of the second cryptographic communication device initializes the verification data until a second period elapses. Is the numerical value represented by the temporary key generation data notified from the temporary key generation data notification unit of the first encryption communication device stored in the verification data storage unit of the second encryption communication device If the verification data is equal to the numerical value represented by the verification data, it is determined that the temporary key generation data notified from the temporary key generation data notification unit of the first cryptographic communication device is valid, and the second cryptographic communication Before the verification data storage unit of the device initializes the verification data, and after the verification data storage unit of the second encryption communication device initializes the verification data, the second period Passed Is the numerical value represented by the temporary key generation data notified from the temporary key generation data notification unit of the first encryption communication device stored in the verification data storage unit of the second encryption communication device And determining that the temporary key generation data notified from the temporary key generation data notifying unit of the first encryption communication device is valid when the verification data is equal to or greater than the numerical value represented by the verification data. The cryptographic communication system according to claim 8. The initialization command generated by the initialization command generation unit of the management device includes information encrypted using the first master key stored by the master key storage unit of the management device,
The initialization command verification unit of the second cryptographic communication device is configured to change the information included in the initialization command notified from the initialization command notification unit of the first cryptographic communication device to the information of the second cryptographic communication device. 6. The encryption communication system according to claim 5, wherein decryption is performed using the second master key stored in the master key storage unit. The first encryption communication device is a device that is physically separated from the management device,
The management device further includes a temporary key notification unit and a temporary key generation data notification unit,
The temporary key notification unit of the management device notifies the first encryption communication device of the first temporary key generated by the temporary key generation unit of the management device,
The temporary key generation data notifying unit of the management device sends the temporary key generation data used by the temporary key generation unit of the management device to generate the first temporary key to the first encryption communication device. Notification to
The first encryption communication device further includes a temporary key storage unit and a temporary key generation data storage unit,
The temporary key storage unit of the first cryptographic communication device stores the first temporary key notified from the temporary key notification unit of the management device,
The temporary key generation data storage unit of the first encryption communication device stores the temporary key generation data notified from the temporary key generation data notification unit of the management device,
The temporary key generation data notifying unit of the first encryption communication device sends the temporary key generation data stored in the temporary key generation data storage unit of the first encryption communication device to the second encryption communication device. The encryption communication system according to any one of claims 1 to 4, characterized in that notification is made.   The cryptographic communication system according to claim 11, wherein the first cryptographic communication device is a mobile terminal. A master key storage unit for storing the master key;
A temporary key generation data verification unit that determines whether or not the temporary key generation data notified from another cryptographic processing device is valid;
When it is determined the other the temporary key generation data verification unit and the temporary key generation data notified from the encryption processing apparatus is valid, and the master key in which the master key storage unit stores, the other use of the notified the temporary key generation data from the encryption processing apparatus, the temporary key generation unit for generating a temporary key,
An encryption processing device comprising: an encryption communication unit that performs encryption communication with the other encryption processing device using the temporary key generated by the temporary key generation unit. The cryptographic processing apparatus further includes a temporary key generation data storage unit and a temporary key generation data update unit,
The temporary key generation data storage unit stores temporary key generation data used by the temporary key generation unit to generate the temporary key;
The temporary key generation data update unit repeatedly updates the temporary key generation data stored in the temporary key generation data storage unit every time the first period elapses,
The temporary key generation data verification unit uses the temporary key generation data stored in the temporary key generation data storage unit and the temporary key generation data notified from the other cryptographic processing device is valid. 14. The cryptographic processing apparatus according to claim 13 , wherein it is determined whether or not there is any. The temporary key generation data stored in the temporary key generation data storage unit is data representing a numerical value,
The temporary key generation data update unit calculates a sum obtained by adding an increment value to the numerical value represented by the temporary key generation data stored in the temporary key generation data storage unit, and stores the temporary key generation data storage Update the temporary key generation data stored by the unit with data representing the calculated sum,
The temporary key generation data verification unit is configured such that the numerical value represented by the temporary key generation data notified from the other cryptographic processing device is the temporary key generation data stored in the temporary key generation data storage unit. 15. The cryptographic processing apparatus according to claim 14 , wherein, when the numeric value is greater than or equal to the numerical value to be expressed, it is determined that the temporary key generation data notified from the other cryptographic processing apparatus is valid. The temporary key generation data storage unit is valid when the temporary key generation data verification unit determines that the temporary key generation data notified from the other cryptographic processing device is valid. The cryptographic processing apparatus according to claim 15 , wherein the temporary key generation data determined by the temporary key generation data verification unit is stored. The cryptographic processing apparatus further includes an initialization command verification unit,
The initialization command verification unit determines whether the initialization command notified from the other cryptographic processing device is valid,
The temporary key generation data storage unit stores the stored temporary key generation data when the initialization command verification unit determines that the initialization command notified from the other cryptographic processing device is valid. cryptographic processing apparatus according to claims 14, wherein the initializing to claim 16. A temporary key generation data verification unit for performing temporary key generation data verification processing for determining whether or not the temporary key generation data notified from another cryptographic processing device is valid;
When the temporary key generation data verification unit determined that the temporary key generation data notified from the other cryptographic processing device is valid, using the master key and the temporary key generation data, A temporary key generation unit for performing a temporary key generation process for generating a temporary key;
A cryptographic communication unit that performs cryptographic communication processing for cryptographic communication with the other cryptographic processing device using the temporary key generated by the temporary key generation processing
A computer program that causes a computer to function as. In a cryptographic communication method in a cryptographic communication system comprising a management device, a first cryptographic communication device, and a second cryptographic communication device,
The management device stores a first master key,
The second encryption communication device stores a second master key that is the same as or corresponds to the first master key stored by the management device,
The management device generates the first temporary key using the first master key stored by the management device and the temporary key generation data,
The second encryption communication device determines whether the temporary key generation data notified from the first encryption communication device is valid,
The second encryption communication device stores the second encryption communication device when the second encryption communication device determines that the temporary key generation data notified from the first encryption communication device is valid. The same as the first temporary key generated by the management device using the second master key and the temporary key generation data determined that the second encryption communication device is valid, or Generate a second temporary key corresponding to the first temporary key,
The first encryption communication device notifies the second encryption communication device of the temporary key generation data used by the management device to generate the first temporary key,
The first cryptographic communication device performs cryptographic communication with the second cryptographic communication device using the first temporary key generated by the management device,
The cryptographic communication method, wherein the second cryptographic communication device performs cryptographic communication with the first cryptographic communication device using the second temporary key generated by the second cryptographic communication device.

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