JP6047933B2 - Information processing apparatus, information processing method, and information processing system - Google Patents

Description

  The present invention relates to an information processing apparatus, an information processing method, and an information processing system.

  Conventionally, a communication method and encryption technology between an IC card and a terminal device are defined by the EMV standard, which is an international de facto standard, and the specifications of secure messaging (Secure Messaging) are also defined (Non-patent Document 1). .

EMV v4.3 Book2 Security and Key Management (November 2011)

In the communication between the IC card and the terminal device described above, when the key stored in the IC card is updated to a new key, the following problem occurs.
When the terminal device transmits a new key as it is to the IC card using the key update command, there is a possibility that the new key is eavesdropped and leaked by a third party. As a countermeasure against such eavesdropping, there is a secure messaging system that encrypts information between a terminal device and an IC card.

  In the secure messaging system, it is necessary to exchange keys for secure messaging in advance, and a key for secure messaging needs to be set in the IC card in advance separately from the key to be updated. For this reason, in order to update the key stored in the IC card, there is a problem that complicated processing must be performed in advance.

  In addition, there is a method in which a terminal device encrypts a new key using a key encryption key separately stored in the IC card and transmits it to the IC card. However, even in this method, it is necessary to previously set an encryption key different from the new key in the IC card.

  Further, in this method, when there are a plurality of keys in the IC card, all the keys are encrypted and updated with the same key. For this reason, when the encryption key is leaked to a third party, there is a problem that communication between the terminal device and the IC card is eavesdropped and all keys are leaked.

  Also, a method of encrypting and updating a plurality of keys with different encryption keys can be considered. However, in this method, it is necessary to prepare encryption keys for the number of keys to be updated.

  The present invention has been proposed in view of such a situation, and an information processing apparatus and an information processing method capable of updating a key while preventing eavesdropping by a third party without performing complicated processing And it aims at providing an information processing system.

The information processing apparatus according to the present invention includes a storage unit that stores a first key and data obtained by encrypting a second key using the same key as the first key stored in the storage unit. Receiving means for receiving certain encrypted data; decrypting means for decrypting encrypted data received by the receiving means into the second key using a first key stored in the storage means; and the storage Control means for performing a key update process for rewriting the first key stored in the means to the second key decrypted by the decryption means , wherein the control means performs the key update process. The first key stored in the first area where the key to be used is stored in the storage means is written in the second area of the storage means, and the second key decrypted by the decryption means is Write to the first area and from the first area to the second key It is determined whether the read and read second key corresponds to the decrypted second key, and in the case of correspondence, the first key in the second area is used as the second key in the first area. In the case where it does not correspond, control is performed to overwrite the second key in the first area with the second key in the first area .

  In the present invention, the receiving means further receives a check code calculated based on the encrypted data, and the decrypting means calculates a check code based on the encrypted data received by the receiving means. When the calculated check code corresponds to the check code received by the receiving unit, the encrypted data received by the receiving unit is decrypted.

The information processing method according to the present invention receives encrypted data, which is data obtained by encrypting the second key using the same key as the first key stored in the storage unit, and receives the received A key for decrypting encrypted data into the second key using the first key stored in the storage unit, and rewriting the first key stored in the storage unit with the decrypted second key When the key update process is performed, the first key stored in the first area where the key to be used is stored in the storage unit is written in the second area of the storage unit. And whether the decrypted second key is written in the first area, the second key is read from the first area, and the read second key corresponds to the decrypted second key. And if it corresponds, the first key of the second area is set to the second key of the first area. Overwriting is not performed, not correspond is characterized by overwriting the first key of the second region to the second key of the first region.

An information processing system according to the present invention encrypts a second key using a first key to generate encrypted data, and transmits to transmit the encrypted data generated by the encryption means Means for storing the first key, storage means for storing the first key, receiving means for receiving the encrypted data transmitted from the information terminal apparatus, and encrypted data received by the receiving means Decrypting means to decrypt the second key using the first key stored in the storage means, and a second key decrypted by the decrypting means from the first key stored in the storage means A control means for performing an update process of the key to be rewritten , wherein the control means, when performing the key update process, includes a first area stored in a first area in which a key to be used is stored. Write the key in the second area of the storage means And writing the second key decrypted by the decryption means into the first area, reading the second key from the first area, and reading the second key and the decrypted second key; If so, the first key in the second area is not overwritten on the second key in the first area. If not, the first key in the second area is not overwritten. And an information processing apparatus having control means for performing control to overwrite the second key in the first area with the second key in the first area .

In the information processing method according to the present invention, the information terminal device encrypts the second key using the first key to generate encrypted data, transmits the generated encrypted data to the information processing device, The information processing device receives encrypted data transmitted from the information terminal device, and decrypts the received encrypted data into the second key using a first key stored in a storage unit. , when the first key stored in the storage unit have a row update processing key rewritten in the second key that is the decoded, performs update processing of the key, the key used among the storage unit Is written in the second area of the storage unit, and the decrypted second key is written in the first area, from the first area to the first area. 2 key is read, and the read second key corresponds to the decrypted second key. If it corresponds, the first key in the second area is not overwritten on the second key in the first area. If not, the first key in the second area is not overwritten. The second key in the first area is overwritten .

  According to the present invention, the key of the information processing apparatus can be updated while preventing the key from leaking to a third party without performing complicated processing in advance.

It is a block diagram which shows the structure of an information processing system. It is a flowchart which shows the encryption process routine by CPU of the information terminal device in 1st Embodiment, and the decoding process routine by CPU of IC card. It is a flowchart which shows the encryption process routine by CPU of the information terminal device in 2nd Embodiment, and the decoding process routine by CPU of IC card. It is a flowchart which shows the encryption processing routine by CPU of the information terminal device in 3rd Embodiment, and the decoding processing routine by CPU of IC card. It is a figure explaining the process of step S51-S55.

Embodiments of the present invention will be described below.
[First Embodiment]
FIG. 1 is a block diagram showing the configuration of the information processing system. The information processing system 1 includes an information terminal device 10 and an IC card 30.

  The information terminal device 10 includes a CPU (Central Processing Unit) 11, a ROM 12 (Read Only Memory), a RAM (Random Access Memory) 13, a bus 14, an interface (I / F) 15, a reader / writer (R / W) 16, an input. Unit 17, display 18, and magnetic disk 19.

  The CPU 11, ROM 12, RAM 13, and interface 15 are connected to each other by a bus 14. The R / W 16, the input unit 17, the display 18, and the magnetic disk 19 are connected to each other by an interface 15. The ROM 12 is a nonvolatile read-only memory. The ROM 12 stores basic software such as an operating system (hereinafter referred to as “OS”).

  The CPU 11 executes various processes in accordance with the OS stored in the ROM 12 and the program (application program) read from the magnetic disk 19 and developed in the RAM 13. The RAM 13 is a volatile memory capable of rewriting stored data, and stores programs necessary for the CPU 11 to execute various processes.

  The interface 15 manages input / output of information among the R / W 16, the input unit 17, the display 18 and the magnetic disk 19. The interface 15 is connected to the CPU 11, ROM 12, and RAM 13 via the bus 14. The R / W 16 is in electrical contact with the contact terminal of the IC card 30 and mediates communication between the CPU 11 and the IC card 30.

  The input unit 17 is, for example, a keyboard or a pointing device, and inputs various commands from the user, other necessary information, and the like according to user operations. The display 18 is an LCD (Liquid Crystal Display), for example, and displays various information such as characters and images. The magnetic disk 19 stores an encryption / decryption application program (for example, an encryption processing routine), a key Kn, a key Ko, attribute information of each key, and data necessary for executing the program.

  The IC card 30 is inserted into the R / W 16 of the information terminal device 10 and can communicate with the information terminal device 10. The IC card 30 includes a communication unit 31 that receives power supply from the R / W 16 and performs contact communication, a CPU 32 connected to the communication unit 31, a RAM 33 connected to the CPU 32, a ROM 34, and a nonvolatile memory 35. Yes.

  In the ROM 34, for example, a control program (for example, a decoding processing routine) of the CPU 32 is stored. The nonvolatile memory 35 includes a program executed by the CPU 32, data necessary for executing the program, a plurality of files, a key Ko for authentication or secure messaging (SM), and attribute information thereof (an encryption algorithm and a key size of the key Ko). Etc.) are stored.

The IC card 30 uses the key Ko stored in the nonvolatile memory 35 to authenticate, for example, a file access request or perform encrypted communication by secure messaging. Here, it is desirable from the viewpoint of security that the key Ko is periodically updated to a new key Kn rather than continuously using the same key Ko.
Therefore, when updating the key Ko to a new key, the information processing system 1 executes the following process so that the key is not leaked due to eavesdropping by a third party.

  FIG. 2 is a flowchart showing an encryption processing routine by the CPU 11 of the information terminal device 10 and a decryption processing routine by the CPU 32 of the IC card 30 in the first embodiment.

  In step S11, the CPU 11 of the information terminal device 10 encrypts the key Kn stored in the magnetic disk 19 based on the key Ko and the attribute information of the key Ko, and generates encrypted data E (K n, Ko). To do. The encryption algorithm for encryption follows the attribute information of the key Ko. Then, the process proceeds to step S12.

  In step S12, the CPU 11 sets the encrypted data E (Kn, Ko) together with the key update command via the R / W 16, and transmits it to the IC card 30. Then, the process proceeds to step S13.

On the other hand, when the CPU 32 of the IC card 30 receives the key update command and the encrypted data E (Kn, Ko) transmitted from the information terminal device 10 via the communication unit 31 in step S31, the process proceeds to step S32.
In step S32, the CPU 32 decrypts the encrypted data E (Kn, Ko) received by the communication unit 31 according to the key Ko and the attribute information of the key Ko stored in the nonvolatile memory 35, and obtains the key Kn. When a new key Kn is extracted, the process proceeds to step S33.

In step S33, the CPU 32 updates the key Ko stored in the nonvolatile memory 35 to a new key Kn, and proceeds to step S34.
In step S <b> 34, the CPU 32 generates a normal end code indicating that the key Ko has been updated to the new key Kn, and transmits this normal end code to the information terminal device 10 via the communication unit 31. Then, the decoding process routine of the CPU 32 ends.

  On the other hand, in the information terminal device 10, in step S13, the CPU 11 receives the normal end code transmitted from the IC card 30 in step S34, and recognizes the state of the IC card 30. Then, the encryption processing routine of the CPU 11 ends.

  As described above, in the information processing system 1 according to the first embodiment, the information terminal device 10 is obtained by encrypting the new key Kn using the same key Ko as the key Ko stored in the IC card 30. The encrypted data E (Kn, Ko) to be transmitted is transmitted to the IC card 30. On the other hand, when receiving the encrypted data E (Kn, Ko) transmitted from the information terminal device 10, the IC card 30 decrypts the encrypted data E (Kn, Ko) using the key Ko stored in itself. The key Kn is obtained and the key Ko is updated to a new key Kn.

  As a result, the information processing system 1 does not need to prepare keys for encrypting the new key Kn in the information terminal device 10 and the IC card 30, respectively, so that the IC card 30 can be prevented while preventing eavesdropping and key leakage. The key Ko can be updated to a new key Kn.

  Further, since the information processing system 1 updates the key Ko of the IC card 30 without using secure messaging (SM), it is not necessary to store an SM key different from the key Ko in the IC card 30, and it is easy. The key Ko can be updated by simple processing. Further, since the information processing system 1 does not need to store the key encryption key in the IC card 30, it is possible to update the key Ko without increasing the memory capacity of the IC card 30.

  Although the case where one key is stored in the IC card 30 has been described in the first embodiment, the same applies to the case where a plurality of keys are stored in the IC card 30. That is, the information terminal device 10 encrypts new keys respectively corresponding to a plurality of old keys (keys currently used) with the old keys, and transmits each encrypted data to the IC card 30. The IC card 30 may decrypt each encrypted data into a new key using the corresponding old key.

  For this reason, when there are a plurality of keys to be updated in the IC card 30, the information terminal device 10 generates encrypted data using different keys for each new key, and sends the encrypted data to the IC card 30. Send. For this reason, even if one key is leaked from the IC card 30, the other keys are not affected, so that safety is ensured even when there are many keys.

[Second Embodiment]
Next, a second embodiment of the present invention will be described. In this embodiment, the same parts and processing steps as those in the first embodiment are denoted by the same reference numerals, overlapping description is omitted, and different points are mainly described.

  The information processing system 1 according to the second embodiment is configured similarly to the first embodiment. Then, the information processing system 1 executes the following process to decrypt the key Kn using the encrypted data E (Kn, Ko) that is not affected by noise or falsification of the communication path.

FIG. 3 is a flowchart showing an encryption processing routine by the CPU 11 of the information terminal device 10 and a decryption processing routine by the CPU 32 of the IC card 30 in the second embodiment.
In step S21, the CPU 11 of the information terminal device 10 encrypts the key Kn stored in the magnetic disk 19 based on the key Ko and the attribute information of the key Ko, and generates encrypted data E (Kn, Ko). Then, the process proceeds to step S22.

In step S22, the CPU 11 calculates a check code (Cc) (redundancy check code) for the encrypted data E (Kn, Ko), and proceeds to step S23. Note that the CPU 11 of the information terminal device 10 and the CPU 32 of the IC card 30 calculate a check code (Cc) according to the same check code calculation algorithm.
In step S23, the CPU 11 transmits the encrypted data E (Kn, Ko) and the check code (Cc) to the IC card 30 via the R / W 16 together with the key update command. Then, the process proceeds to step S24.

On the other hand, in the IC card 30, in step S41, the CPU 32 receives the encrypted data E (Kn, Ko) and the check code (Cc) together with the key update command via the communication unit 31, and proceeds to step S42. .
In step S42, the CPU 32 calculates a check code (Cc) for the received encrypted data E (Kn, Ko), and proceeds to step S43.

In step S43, the CPU 32 determines whether or not the check code (Cc) received by the communication unit 31 in step S41 matches the check code (Cc) calculated in step S42. If YES in step S45, the flow advances to step S45.
In step S44, the CPU 32 does not perform a key update process, generates an error code indicating that the received check code (Cc) and the calculated check code (Cc) do not match, and transmits this error code to the communication unit. The information is transmitted to the information terminal device 10 via 31. Then, this routine ends.

On the other hand, in step S45, the CPU 32 decrypts the encrypted data E (Kn, Ko) received by the communication unit 31 according to the key Ko stored in the nonvolatile memory 35 and the attribute information of the key Ko to obtain the key Kn. The process proceeds to step S46.
In step S46, the CPU 32 updates the key Ko stored in the nonvolatile memory 35 to a new key Kn, and proceeds to step S47.
In step S <b> 47, the CPU 32 generates a normal end code indicating that the key Ko has been updated to the new key Kn, and transmits this normal end code to the information terminal device 10 via the communication unit 31. Then, the decoding process routine of the CPU 32 ends.

  On the other hand, in the information terminal device 10, in step S24, the CPU 11 receives the error code transmitted from the IC card 30 in step S44 or the normal end code transmitted in step S47, and recognizes the state of the IC card 30. . Then, the encryption processing routine of the CPU 11 ends.

  As described above, in the information processing system 1 according to the second embodiment, the information terminal device 10 calculates the check code (Cc) of the encrypted data E (Kn, Ko) and the encrypted data E (Kn). , Ko) and the check code (Cc) are transmitted to the IC card 30. On the other hand, the IC card 30 calculates the check code (Cc) of the received encrypted data E (Kn, Ko) and determines whether the received check code (Cc) corresponds to the calculated check code (Cc). In the case of correspondence (for example, coincidence), the encrypted data E (Kn, Ko) is decrypted to the key Kn. Thereby, the IC card 30 can update the key Ko to the new key Kn by using the encrypted data E (Kn, Ko) that is not affected by the noise of the communication path or the tampering.

[Third Embodiment]
Next, a third embodiment of the present invention will be described. In addition, the same code | symbol is attached | subjected to the same site | part and processing step as embodiment mentioned above, and while overlapping description is abbreviate | omitted, a different point is mainly demonstrated.

  An information processing system 1 according to the third embodiment is configured similarly to the first embodiment. The information processing system 1 executes the following process in order to confirm whether the new key Kn is correctly stored in the IC card 30.

  FIG. 4 is a flowchart showing an encryption processing routine by the CPU 11 of the information terminal device 10 and a decryption processing routine by the CPU 32 of the IC card 30 in the third embodiment. Note that steps S21a to S24a and steps S41a to S45a in FIG. 4 are the same as the corresponding steps (steps S21 to S24 and steps S41 to S45) in FIG. For this reason, FIG. 4 demonstrates mainly step S51-S55.

When the CPU 32 of the IC card 30 decrypts the encrypted data E (Kn, Ko) and extracts the key Kn, the process proceeds to the next step S51.
FIG. 5 is a diagram for explaining the processing of steps S51 to S55.
In step S51, the CPU 32 copies the old key Ko stored in the non-volatile memory 35 to a sub area (for example, the RAM 33), temporarily stores it, and stores the key Kn extracted by decryption in the main area (for example, the non-volatile memory 35). And proceed to step S52. Here, the main area refers to an area in which used keys are always stored. The sub area is a storage area for temporarily saving the old key Ko during the key update process, and is an area different from the main area.

  In steps S52 and S53, the CPU 32 reads the key Kn from the main area and determines whether the key Kn extracted in step S45 matches the key Kn read from the main area. If they match, the process proceeds to step S55, and if they do not match, the process proceeds to step S54.

In step S54, the CPU 32 reads the key Ko from the sub area, overwrites the key Ko with the key Kn stored in the main area, and sends an error code indicating that the key Ko update process has failed to the information terminal device 10. Send. Then, this routine ends.
On the other hand, in step S55, the CPU 32 transmits to the information terminal device 10 a normal end code indicating that the update process of the key Ko has ended normally. Then, this routine ends.

  As described above, in the information processing system 1 according to the third embodiment, the IC card 30 decrypts the encrypted data E (Kn, Ko) to obtain the key Kn, and writes this key Kn into the main area. After that, the data is read again from the main area, and it is compared whether the read key Kn matches the decrypted key Kn. As a result, the IC card 30 can confirm whether the new key Kn has been correctly written in the main area, and can prevent a key update failure due to a writing error.

  In addition, this invention is not limited to embodiment mentioned above, It can apply also to what was changed in the design within the range of the matter described in the claim. For example, in the third embodiment, the main area and the sub area are not limited to the nonvolatile memory 35 and the RAM 33, respectively, and may be other different storage media or the same storage medium. Also good. Further, the IC card 30 is not limited to a contact type card and a non-contact type card, but can also be applied to a hybrid card or a two-way access card combining them.

Further, the program for realizing the functions of the information terminal device 10 or the IC card 30 in FIG. 1 is recorded on a computer-readable recording medium, and the program recorded on the recording medium is read into a computer system and executed. By doing so, key update management may be performed. Here, the “computer system” includes an OS and hardware such as peripheral devices.
Further, the “computer system” includes a homepage providing environment (or display environment) if a WWW system is used.
The “computer-readable recording medium” refers to a storage device such as a flexible medium, a magneto-optical disk, a portable medium such as a ROM and a CD-ROM, and a hard disk incorporated in a computer system. Further, the “computer-readable recording medium” refers to a volatile memory (RAM) in a computer system that becomes a server or a client when a program is transmitted via a network such as the Internet or a communication line such as a telephone line. In addition, those holding programs for a certain period of time are also included. The program may be a program for realizing a part of the functions described above, and may be a program capable of realizing the functions described above in combination with a program already recorded in a computer system.

1 Information Processing System 10 Information Terminal Device 11 CPU
16 R / W
30 IC card 31 communication unit 32 CPU
33 RAM
34 ROM
35 Nonvolatile memory

Claims (5)

Storage means for storing a first key;
Receiving means for receiving encrypted data, which is data obtained by encrypting the second key using the same key as the first key stored in the storage means;
Decryption means for decrypting encrypted data received by the receiving means into the second key using a first key stored in the storage means;
Control means for performing a key update process for rewriting the first key stored in the storage means with the second key decrypted by the decryption means;
Equipped with a,
The control means writes the first key stored in the first area where the key to be used among the storage means is stored in the second area of the storage means when performing the key update process. The second key decrypted by the decryption means is written to the first area, the second key is read from the first area, and the read second key corresponds to the decrypted second key. If it corresponds, the first key in the second area is not overwritten with the second key in the first area. If not, the first key in the second area is not overwritten. The information processing apparatus is characterized by performing control to overwrite the second key in the first area. The receiving means further receives a check code calculated based on the encrypted data,
The decrypting means calculates a check code based on the encrypted data received by the receiving means, and when the calculated check code corresponds to the check code received by the receiving means, the receiving means The information processing apparatus according to claim 1, wherein the received encrypted data is decrypted. Receiving encrypted data that is data obtained by encrypting the second key using the same key as the first key stored in the storage unit;
Decrypting the received encrypted data into the second key using a first key stored in the storage unit;
There row update processing key rewrite the first key stored in the storage unit to the second key that is the decoded,
When performing the key update process, the first key stored in the first area where the key to be used is stored in the storage unit is written in the second area of the storage unit and the decrypted Write a second key to the first area, read the second key from the first area, determine whether the read second key corresponds to the decrypted second key, and respond In this case, the first key in the second area is not overwritten on the second key in the first area. If not, the first key in the second area is set to the second key in the first area. An information processing method characterized by overwriting the key. An information terminal device comprising: encryption means for encrypting the second key using the first key to generate encrypted data; and transmission means for transmitting the encrypted data generated by the encryption means; ,
Storage means for storing the first key; reception means for receiving encrypted data transmitted from the information terminal apparatus; and first data stored in the storage means for receiving encrypted data received by the receiving means. Decrypting means for decrypting the second key using the key, and control means for performing key update processing for rewriting the first key stored in the storage means to the second key decrypted by the decrypting means When the key updating process is performed, the control unit stores the first key stored in the first area in the storage unit in which the key to be used is stored in the second area of the storage unit. Writing, writing the second key decrypted by the decryption means into the first area, reading the second key from the first area, and reading the second key and the decrypted second key; in the case but that it is determined whether the corresponding, corresponding The overwrite the first key in the second region to the second key of the first region is not performed, if not supported the first key of the second region to the second key of the first region An information processing apparatus having control means for performing overwriting control;
An information processing system comprising: The information terminal device generates encrypted data by encrypting the second key using the first key, transmits the generated encrypted data to the information processing device,
The information processing device receives encrypted data transmitted from the information terminal device, and decrypts the received encrypted data into the second key using a first key stored in a storage unit. , when the first key stored in the storage unit have a row update processing key rewritten in the second key that is the decoded, performs update processing of the key, the key used among the storage unit Is written in the second area of the storage unit, and the decrypted second key is written in the first area, from the first area to the first area. 2 is read, and it is determined whether the read second key and the decrypted second key correspond to each other. If they correspond, the first key of the second area is overwriting for the second key is not performed, if not supported the first key of the second region The information processing method characterized by overwriting the second key 1 region.

Images