JP2018082362A - Communication system, communication device, server device, communication method, and computer program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the security of a communication device, such as an IoT device, included in a communication system, such as an IoT system.SOLUTION: A communication method includes: a key storage step, by a second computation processing device, of storing a first key and a second key used for communication between a communication device and a server device; an authentication processing step, by the second computation processing device, of performing an authentication process with the server device with the first key; a key transmission and reception step, by the second computation processing device, of transmitting or receiving a third key to/from the server device by encryption communication using the second key; and a communication step, by a first computation processing device, of performing encryption communication with the server device with the third key.SELECTED DRAWING: Figure 10

Description

  The present invention relates to a communication system, a communication device, a server device, a communication method, and a computer program.

Embedded devices for specific purposes such as traffic lights and weather sensors are installed throughout society. IoT devices mounted on these embedded devices are connected to the Internet and can send and receive information. In the Internet of Things (IoT) world, the IoT system includes a wide variety of powerless IoT devices. When the server included in the IoT system acquires the information transmitted by the IoT device, the server processes the information.
A public key cryptosystem is known as one technique for concealing communication data. In the public key cryptosystem, a public key (public key certificate) is generally exchanged using PKI (Public Key Infrastructure) (for example, see Non-Patent Document 1).

ITpro, "Introduction to Information Security-PKI (Part 2) --- X.509 Certificate and PKI Mechanism", [November 15, 2016 search], Internet <URL: http://itpro.nikkeibp.co. jp / article / COLUMN / 20060725/244233 / ＞

It is assumed that a fake IoT device is connected to the Internet and erroneous information is transmitted from the fake IoT device to the server. In this case, the result processed by the server is incorrect. However, it is difficult to determine whether the IoT device connected to the Internet is a true IoT device or a fake IoT device.
In addition, the security of the IoT device may be violated. However, it is difficult to add a sophisticated security countermeasure function to a weak IoT device.
The present invention has been made to solve the above problems, and an object thereof is to improve the security of a communication apparatus such as an IoT device included in a communication system such as an IoT system.

(1) One embodiment of the present invention is a communication system that performs communication between a communication device and a server device, the server device, a first arithmetic processing device mounted on the communication device, and the communication device. A second arithmetic processing unit, which is a secure element to be mounted, and the second arithmetic processing unit stores a first key and a second key used for communication between the communication device and the server device. Between the communication device key storage unit, the communication device authentication processing unit that performs authentication processing with the server device using the first key, and the server device by encrypted communication using the second key. A communication device key transmission / reception unit for transmitting or receiving the third key in the communication device communication, wherein the first arithmetic processing device performs cryptographic communication with the server device using the third key. The server device is the same as the communication device. A server key processing unit that stores the first key and the second key, and a server authentication processing unit that performs an authentication process with the communication device authentication processing unit of the communication device using the first key; A server key transmission / reception unit that transmits or receives the third key to / from the communication device key transmission / reception unit of the communication device by encrypted communication using the second key, and using the third key, A server communication unit that performs cryptographic communication with the communication device communication unit of the communication device.

(2) One embodiment of the present invention is a communication system that performs communication between a communication device and a server device. The server device, a first arithmetic processing device mounted on the communication device, and the communication device A second arithmetic processing unit, which is a secure element to be mounted, and the second arithmetic processing unit stores a first key used for communication between the communication device and the server device A key storage unit, and a communication device authentication processing unit that performs authentication processing with the server device using the first key, wherein the first arithmetic processing device includes the communication device and the server device. Communication for transmitting or receiving a third key between the first communication device key storage unit for storing the second key used for communication between the server device and the server device by encrypted communication using the second key. The device key transmission / reception unit and the third key are used to A communication device communication unit that performs encrypted communication with the communication device, and the server device stores the first key and the second key that are the same as the communication device, and the first A server authentication processing unit that performs authentication processing with the communication device authentication processing unit of the communication device using a key, and the communication device key transmission / reception unit of the communication device by encrypted communication using the second key. A server key transmission / reception unit that transmits or receives the third key to / from the server, and a server communication unit that performs cryptographic communication with the communication device communication unit of the communication device using the third key; It is a communication system provided with.

(3) According to one aspect of the present invention, in the communication system according to (1) or (2), the second arithmetic processing unit includes a communication device master key storage unit that stores a master key, and the master key. And a communication device key generation unit that generates the first key and the second key using a communication device correspondence identifier corresponding to the communication device.
(4) According to one aspect of the present invention, in the communication system according to any one of (1) to (3), the server device stores a server master key storage unit that stores the same master key as the communication device, and the master A communication system further comprising: a server key generation unit that generates the first key and the second key using a key and a communication device correspondence identifier corresponding to the communication device.
(5) According to one aspect of the present invention, in the communication system according to any one of (3) and (4), the first arithmetic processing device uses the communication device correspondence identifier as the second arithmetic processing device and the server device. The communication device further includes a communication device corresponding identifier notification unit that notifies the communication device.

(6) One embodiment of the present invention is a communication device that communicates with a server device, and includes a first arithmetic processing device and a second arithmetic processing device that is a secure element, and the second arithmetic processing device includes: A communication device key storage unit for storing a first key and a second key used for communication between the communication device and the server device, and an authentication process between the server device using the first key. A communication device authentication processing unit to perform, and a communication device key transmission / reception unit that transmits or receives a third key to or from the server device by encrypted communication using the second key. Is a communication device including a communication device communication unit that performs encrypted communication with the server device using the third key.

(7) One embodiment of the present invention is a communication device that communicates with a server device, and includes a first arithmetic processing device and a second arithmetic processing device that is a secure element, and the second arithmetic processing device includes: Communication that performs authentication processing between the second communication device key storage unit that stores the first key used for communication between the communication device and the server device, and the server device using the first key A device authentication processing unit, wherein the first arithmetic processing unit includes a first communication device key storage unit that stores a second key used for communication between the communication device and the server device; A communication device key transmission / reception unit that transmits or receives a third key to / from the server device by encryption communication using two keys, and performs encryption communication to / from the server device using the third key. And a communication device communication unit for performing communication.

(8) One aspect of the present invention is a server device that communicates with a communication device, using a server key storage unit that stores the same first key and second key as the communication device, and the first key. A server authentication processing unit that performs authentication processing with a communication device authentication processing unit of a second arithmetic processing device that is a secure element of the communication device, and a communication device of the communication device by encrypted communication using the second key A server key transmission / reception unit that transmits or receives a third key to / from the key transmission / reception unit, and a server communication unit that performs cryptographic communication with the communication device communication unit of the communication device using the third key; Are server devices.

(9) One aspect of the present invention is a communication method between a communication device and a server device, and the communication device includes a first arithmetic processing device and a second arithmetic processing device that is a secure element, A key storage step in which the second arithmetic processing unit stores a first key and a second key used for communication between the communication device and the server device; and the second arithmetic processing unit includes the first key. An authentication processing step for performing an authentication process with the server device using the second processing unit, and the second arithmetic processing device obtains a third key with the server device by encrypted communication using the second key. A key transmission / reception step for transmitting or receiving; and a communication step in which the first arithmetic processing device performs cryptographic communication with the server device using the third key.

(10) One aspect of the present invention is a communication method between a communication device and a server device, and the communication device includes a first arithmetic processing device and a second arithmetic processing device that is a secure element, A first key storage step in which a second arithmetic processing unit stores a first key used for communication between the communication device and the server device; and the second arithmetic processing unit uses the first key. And an authentication processing step for performing an authentication process with the server device, and a second key in which the first arithmetic processing device stores a second key used for communication between the communication device and the server device. A key storing step, a key sending / receiving step in which the first arithmetic processing device transmits or receives a third key to / from the server device by encrypted communication using the second key, and the first arithmetic processing device. Using the third key, the server device A communication step of performing encrypted communication with a communication method comprising.

(11) According to one aspect of the present invention, a second key, which is a secure element, provided in a communication device that communicates with a server device, a first key used for communication between the communication device and the server device, and A communication device key storage function for storing a second key, a communication device authentication processing function for performing authentication processing with the server device using the first key, and encryption communication using the second key, A communication device key transmission / reception function for transmitting or receiving a third key to / from the server device, and the first computer provided in the communication device uses the third key to communicate with the server device. It is a computer program for realizing a communication device communication function for performing encrypted communication between the two.

(12) According to one aspect of the present invention, a second key that is a secure element provided in a communication device that communicates with a server device is provided with a first key used for communication between the communication device and the server device. A second communication device key storage function to be stored and a communication device authentication processing function for performing authentication processing with the server device using the first key are realized, and the first computer provided in the communication device The first communication device key storage function for storing a second key used for communication between the communication device and the server device, and the server device by encrypted communication using the second key. A computer program for realizing a communication device key transmission / reception function for transmitting or receiving a third key and a communication device communication function for performing cryptographic communication with the server device using the third key. .

(13) One embodiment of the present invention uses a server key storage function for storing the same first key and second key as the communication device in a computer of the server device that communicates with the communication device, and the first key. The communication device communicates with the server authentication processing function for performing authentication processing with the communication device authentication processing unit of the second arithmetic processing device, which is a secure element of the communication device, and encrypted communication using the second key. A server key transmission / reception function for transmitting or receiving a third key to / from the device key transmission / reception unit, and a server communication function for performing cryptographic communication with the communication device communication unit of the communication device using the third key And a computer program for realizing the above.

  ADVANTAGE OF THE INVENTION According to this invention, the security of communication apparatuses, such as an IoT device contained in communication systems, such as an IoT system, can be improved.

It is a figure which shows the structural example 1 (communication system 1) of the communication system which concerns on one Embodiment. It is a block diagram which shows the structural example of the server apparatus 2000 which concerns on one Embodiment. It is a block diagram which shows the hardware structural example of the IoT device 1040 which concerns on one Embodiment. It is a block diagram which shows the hardware structural example of the communication module 1051 which concerns on one Embodiment. It is a figure which shows the structural example 2 (communication system 2) of the communication system which concerns on one Embodiment. It is a block diagram which shows the hardware structural example of the communication gateway apparatus 1050 which concerns on one Embodiment. It is a figure which shows the structural example 3 (communication system 3) of the communication system which concerns on one Embodiment. It is a figure which shows the function structural example of the 1st arithmetic processing unit 500 which concerns on one Embodiment. It is a figure which shows the function structural example of the 2nd arithmetic processing unit 600 which concerns on one Embodiment. It is a sequence chart which shows Example 1 of the communication method which concerns on one Embodiment. It is a sequence chart which shows Example 2 of the communication method which concerns on one Embodiment. It is a sequence chart which shows Example 3 of the communication method which concerns on one Embodiment. It is a sequence chart which shows Example 4 of the communication method which concerns on one Embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[Configuration example of communication system]
A configuration example of the communication system according to the present embodiment will be described.

(Configuration example 1 of communication system)
FIG. 1 is a diagram showing a configuration example 1 (communication system 1) of a communication system according to the present embodiment. In FIG. 1, the communication system 1 includes a server device 2000 and an IoT device 1040. The server apparatus 2000 and the IoT device 1040 are connected via a communication network 3000 such as the Internet.

  The IoT device 1040 is a communication device. The IoT device 1040 includes a communication module 1051. The communication module 1051 performs wireless communication using a wireless communication network. The communication module 1051 includes a SIM (Subscriber Identity Module) 1052. The SIM 1052 is a SIM in which information for using the wireless communication network is written. The communication module 1051 can use the SIM 1052 to connect to the wireless communication network and perform wireless communication. Note that an eSIM (Embedded Subscriber Identity Module) may be used as the SIM 1052. SIM and eSIM are examples of secure elements (SE). SIM and eSIM have tamper resistant properties.

  FIG. 2 is a block diagram illustrating a configuration example of the server apparatus 2000 according to the present embodiment. In FIG. 2, the server device 2000 includes a communication unit 11, a storage unit 12, a key generation unit 15, a key transmission / reception unit 16, and an authentication processing unit 18. The communication unit 11 communicates with other devices via a communication line. The storage unit 12 stores data. The key generation unit 15 generates a key. The key transmission / reception unit 16 transmits or receives a key to or from another communication device. The authentication processing unit 18 performs authentication processing with other communication devices.

  The functions of the server device 2000 are realized by a CPU (Central Processing Unit) included in the server device 2000 executing a computer program. Note that the server device 2000 may be configured using a general-purpose computer device, or may be configured as a dedicated hardware device.

  FIG. 3 is a block diagram illustrating a hardware configuration example of the IoT device 1040 according to the present embodiment. In FIG. 3, the IoT device 1040 includes a CPU 110, a storage unit 112, an interface unit 116, and a communication module 1051. These units are configured to exchange data.

  The CPU 110 controls the IoT device 1040. This control function is realized by the CPU 110 executing a computer program. The storage unit 112 stores a computer program executed by the CPU 110 and various data. The storage unit 112 stores a computer program for realizing various functions of the IoT device 1040. Various functions of the IoT device 1040 are realized by the CPU 110 executing the computer program.

  The interface unit 116 transmits / receives data to / from an external device of the local IoT device 1040. The interface unit 116 includes a wireless device that performs wireless communication using a wireless communication technology such as Bluetooth (registered trademark), WiFi (registered trademark), or near field communication (NFC). Also good. The interface unit 116 may include a wireless or wired communication interface connected to the communication network 3000.

  The communication module 1051 includes a SIM 1052. The communication module 1051 can use the SIM 1052 to connect to a wireless communication network corresponding to the SIM 1052 and perform wireless communication. The IoT device 1040 uses the communication module 1051 to communicate with an external device. For example, the IoT device 1040 may communicate with the server apparatus 2000 using the communication module 1051.

  Note that the IoT device 1040 may include a device such as a sensor device not shown in FIG. 3 as necessary.

  FIG. 4 is a block diagram illustrating a hardware configuration example of the communication module 1051 according to the present embodiment. In FIG. 4, the communication module 1051 includes a CPU 1053, a storage unit 1054, an interface unit 1055, and a SIM 1052. These units are configured to exchange data. The communication module 1051 is a communication device.

  The CPU 1053 controls the communication module 1051. This control function is realized by the CPU 1053 executing a computer program. The storage unit 1054 stores a computer program executed by the CPU 1053 and various data. The storage unit 1054 stores a computer program for realizing various functions of the communication module 1051. Various functions of the communication module 1051 are realized by the CPU 1053 executing the computer program.

  The interface unit 1055 transmits / receives data to / from an external device of the own communication module 1051. The SIM 1052 implements various functions of the SIM 1052 by executing computer programs for realizing various functions of the SIM 1052 itself.

(Configuration example 2 of communication system)
FIG. 5 is a diagram showing a configuration example 2 (communication system 2) of the communication system according to the present embodiment. In FIG. 5, parts corresponding to those in FIG. The communication system 2 illustrated in FIG. 5 includes a server device 2000, an IoT device 1040, and a communication gateway device 1050. Server device 2000 and communication gateway device 1050 are connected via communication network 3000. Communication gateway apparatus 1050 and IoT device 1040 are connected via communication network 3000. The communication gateway device 1050 monitors communication performed by the IoT device 1040 with an external device via the communication network 3000. The communication gateway device 1050 is a communication device. The communication gateway device 1050 includes a communication module 1051. The communication module 1051 includes a SIM 1052.

  FIG. 6 is a block diagram illustrating a hardware configuration example of the communication gateway device 1050 according to the present embodiment. In FIG. 6, the communication gateway device 1050 includes a CPU 210, a storage unit 212, an interface unit 216, and a communication module 1051. These units are configured to exchange data. The communication module 1051 includes a SIM 1052.

  The CPU 210 controls the communication gateway device 1050. This control function is realized by the CPU 210 executing a computer program. The storage unit 212 stores a computer program executed by the CPU 210 and various data. The storage unit 212 stores a computer program for realizing various functions of the communication gateway device 1050. Various functions of the communication gateway device 1050 are realized by the CPU 210 executing the computer program.

  The interface unit 216 transmits / receives data to / from an external device of the self-communication gateway device 1050. The interface unit 216 may include a wireless or wired communication interface connected to the communication network 3000. The communication module 1051 and the SIM 1052 are as described above.

(Configuration example 3 of communication system)
FIG. 7 is a diagram showing a configuration example 3 (communication system 3) of the communication system according to the present embodiment. In FIG. 7, parts corresponding to those in FIGS. 1 and 5 are given the same reference numerals. The communication system 3 illustrated in FIG. 7 includes a server device 2000, an IoT device 1040, and a communication gateway device 1050. Server device 2000 and communication gateway device 1050 are connected via communication network 3000. Communication gateway apparatus 1050 and IoT device 1040 are connected via communication path 3010. The communication path 3010 is a communication path independent of the communication network 3000. The communication path 3010 may be a wireless communication path or a wired communication path. The communication path 3010 may be a wireless or wired LAN (Local Area Network).

  The IoT device 1040 communicates with a device such as the server device 2000 connected to the communication network 3000 via the communication gateway device 1050. The communication gateway device 1050 monitors communication performed by the IoT device 1040 with an external device via the communication network 3000. The communication gateway device 1050 includes a communication module 1051. The communication module 1051 includes a SIM 1052.

  The above is the description of the configuration example of the communication system according to the present embodiment.

  FIG. 8 is a diagram illustrating a functional configuration example of the first arithmetic processing device 500 according to the present embodiment. In FIG. 8, the first arithmetic processing device 500 includes a communication unit 501, a storage unit 502, a key transmission / reception unit 503, and an identifier notification unit 504. The communication unit 501 communicates with a device outside the first arithmetic processing device 500. The storage unit 502 stores data. The key transmission / reception unit 503 transmits or receives a key to or from the server device 2000. The identifier notifying unit 504 notifies the communication device corresponding identifier.

  In the present embodiment, the IoT device 1040 or the communication module 1051 of the communication system 1 may have the function of the first arithmetic processing device 500. Alternatively, the communication gateway device 1050 or the communication module 1051 of the communication system 2 may have the function of the first arithmetic processing device 500. Alternatively, the communication gateway device 1050 or the communication module 1051 of the communication system 3 may have the function of the first arithmetic processing device 500.

  FIG. 9 is a diagram illustrating a functional configuration example of the second arithmetic processing device 600 according to the present embodiment. In FIG. 9, the second arithmetic processing device 600 includes a key generation unit 601, a storage unit 602, a key transmission / reception unit 603, and an authentication processing unit 604. The key generation unit 601 generates a key. The storage unit 602 stores data. The key transmission / reception unit 603 transmits or receives a key to or from the server device 2000. The authentication processing unit 604 performs authentication processing with the server device 2000.

  The second arithmetic processing unit 600 is a secure element. The second processing unit 600 may be a semiconductor product having tamper resistance. For example, the second arithmetic processing unit 600 may be configured using a SIM, eSIM, or IC (Integrated Circuit) chip.

  In the present embodiment, the SIM 1052 of the communication module 1051 of the IoT device 1040 of the communication system 1 may have the function of the second arithmetic processing device 600. Alternatively, the SIM 1052 of the communication module 1051 of the communication gateway device 1050 of the communication system 2 may have the function of the second arithmetic processing device 600. Alternatively, the SIM 1052 of the communication module 1051 of the communication gateway device 1050 of the communication system 3 may have the function of the second arithmetic processing device 600. The SIM 1052 is a secure element. The SIM 1052 has tamper resistance. Alternatively, the IoT device 1040 or the communication gateway device 1050 of the communication systems 1, 2, and 3 may include an IC chip that is a secure element and has tamper resistance, and the IC chip may have the function of the second arithmetic processing device 600. .

[Configuration example of first arithmetic processing device and second arithmetic processing device]
A configuration example of the first arithmetic processing device and the second arithmetic processing device according to the present embodiment will be described.

(Configuration example 1 of the first arithmetic processing device and the second arithmetic processing device)
In the first configuration example of the first arithmetic processing device and the second arithmetic processing device, in the communication system 1, the IoT device 1040 as an example of the first arithmetic processing device 500 has the function of the first arithmetic processing device 500, and the second arithmetic processing device 500 As an example of the processing device 600, the SIM 1052 of the communication module 1051 of the IoT device 1040 has the function of the second arithmetic processing device 600. When the CPU 110 of the IoT device 1040 executes a computer program for realizing the functions of the first arithmetic processing device 500, the functions of the first arithmetic processing device 500 are realized. When the SIM 1052 of the communication module 1051 of the IoT device 1040 executes a computer program for realizing the function of the second arithmetic processing device 600, the function of the second arithmetic processing device 600 is realized.

(Configuration example 2 of the first arithmetic processing device and the second arithmetic processing device)
In the configuration example 2 of the first arithmetic processing device and the second arithmetic processing device, the communication gateway device 1050 includes the function of the first arithmetic processing device 500 as an example of the first arithmetic processing device 500 in the communication systems 2 and 3. As an example of the second arithmetic processing device 600, the SIM 1052 of the communication module 1051 of the communication gateway device 1050 has the function of the second arithmetic processing device 600. When the CPU 210 of the communication gateway device 1050 executes a computer program for realizing the function of the first arithmetic processing device 500, the function of the first arithmetic processing device 500 is realized. When the SIM 1052 of the communication module 1051 of the communication gateway apparatus 1050 executes a computer program for realizing the function of the second arithmetic processing apparatus 600, the function of the second arithmetic processing apparatus 600 is realized.

(Configuration example 3 of the first arithmetic processing device and the second arithmetic processing device)
In the configuration example 3 of the first arithmetic processing device and the second arithmetic processing device, in the communication systems 1, 2, and 3, the communication module 1051 as an example of the first arithmetic processing device 500 has the function of the first arithmetic processing device 500. As an example of the second arithmetic processing unit 600, the SIM 1052 of the communication module 1051 has the function of the second arithmetic processing unit 600. When the CPU 1053 of the communication module 1051 executes a computer program for realizing the function of the first arithmetic processing device 500, the function of the first arithmetic processing device 500 is realized. When the SIM 1052 of the communication module 1051 executes a computer program for realizing the function of the second arithmetic processing device 600, the function of the second arithmetic processing device 600 is realized.

[Configuration example of identifier for communication device]
A configuration example of the communication device correspondence identifier according to the present embodiment will be described. The communication device correspondence identifier is an identifier corresponding to the communication device.

(Configuration example 1 of communication device correspondence identifier)
In the configuration example 1 of the communication device correspondence identifier, the communication device correspondence identifier is configured using the identification information (communication device identification information) of the communication device. The communication device identification number may be a communication device manufacturing number or serial number. As the communication device identification information used for the communication device correspondence identifier, for example, the communication device identification information of the communication device such as the identification information of the IoT device 1040, the identification information of the communication module 1051, and the identification information of the communication gateway device 1050 can be applied. Moreover, you may comprise a communication apparatus corresponding | compatible identifier using one or some communication apparatus identification information among the communication apparatus identification information of each of these communication apparatuses. The communication device correspondence identifier may be communication device identification information, or may be information composed of communication device identification information and other information.

(Configuration example 2 of communication device correspondence identifier)
In the configuration example 2 of the communication device correspondence identifier, the communication device correspondence identifier is configured using IMSI (International Mobile Subscriber Identity) or ICCID (Integrated Circuit Card ID) stored in the SIM 1052 mounted on the communication device. The communication device correspondence identifier may be IMSI, or may be information composed of IMSI and other information. Alternatively, the communication device correspondence identifier may be ICCID, or may be information composed of ICCID and other information. For example, the communication device correspondence identifier may be information including a plurality of IMSI, ICCID, and communication device identification information.

[Example of key generation method]
An example of a key generation method according to this embodiment will be described. In the present embodiment, a MAC key K_mac_gen and an ENC key K_enc_gen are generated as examples of keys. The MAC key K_mac_gen is a key used for authentication processing. The ENC key K_enc_gen is a key used for encryption communication in key transmission or reception. In the present embodiment, the MAC key K_mac_gen corresponds to the first key, and the ENC key K_enc_gen corresponds to the second key.

  In the present embodiment, a common key is generated using a predetermined key generation function. An example of the key generation function will be described below.

(Key generation function example 1)
Common key = digest (Master_Secret, UNID, Key_ID (Nk))
However, Master_Secret is a master key. The UNID is a communication device corresponding identifier. Key_ID (Nk) is a key type identifier. Nk is a variable representing the type of key. The digest (Master_Secret, UNID, Key_ID (Nk)) is a digest value generated from the master key Master_Secret, the communication device corresponding identifier UNID, and the key type identifier Key_ID (Nk). Examples of the digest value include a value calculated by a hash function or a value calculated by an exclusive OR operation. For example, the common key is a hash function value calculated using the master key Master_Secret, the communication device corresponding identifier UNID, and the key type identifier Key_ID (Nk) as input values.

If the value of the key type identifier Key_ID (Nk) is different, the digest value is different. By changing the value of the key type identifier Key_ID (Nk), different common keys can be generated from the same master key Master_Secret and the communication device corresponding identifier UNID. For example, the key type identifier of the MAC key is Key_ID (mac), and the key type identifier of the ENC key is Key_ID (enc). In this case, using the master key Master_Secret, the communication device corresponding identifier UNID, and the key type identifier Key_ID (mac), Key_ID (enc),
MAC key K_mac_gen = digest (Master_Secret, UNID, Key_ID (mac)),
ENC key K_enc_gen = digest (Master_Secret, UNID, Key_ID (enc)),
Thus, the MAC key K_mac_gen and the ENC key K_enc_gen can be generated as different keys.

(Example 2 of key generation function)
In example 2 of the key generation function, a CMAC (Cipher-based Message Authentication Code) is generated as a common key.
Common key = CMAC (Master_Secret; UNID, Key_ID (Nk))
However, in CMAC (A; B), key A is a key used to generate CMAC, and data B is data to be generated by CMAC. Thus, in the second example of the key generation function, the common key is “CMAC of data B” generated using the key A. In CMAC (Master_Secret; UNID, Key_ID (Nk)), the master key Master_Secret is a key used for generation of CMAC, and the concatenated data of the communication device correspondence identifier UNID and key type identifier Key_ID (Nk) is the target of CMAC generation It is data of. Thus, in the second example of the key generation function, the common key is “CMAC of the concatenated data of the communication device correspondence identifier UNID and the key type identifier Key_ID (Nk)” generated using the master key Master_Secret.

  In the example 2 of the key generation function, the CMAC is different if the value of the key type identifier Key_ID (Nk) is different. For this reason, in the second example of the key generation function, similarly to the first example of the key generation function, by changing the value of the key type identifier Key_ID (Nk), it differs from the same master key Master_Secret and the communication device corresponding identifier UNID. A common key can be generated.

[Example of communication method]
Next, an example of a communication method according to the present embodiment will be described with reference to FIGS. 10, 11, 12, and 13. 10, 11, 12, and 13, the communication device 1001 includes a first arithmetic processing device 500 and a second arithmetic processing device 600.

  Further, an encrypted communication path may be used as a communication path between the server apparatus 2000 and the first arithmetic processing apparatus 500. For example, the server device 2000 and the first arithmetic processing device 500 may perform https (hypertext transfer protocol secure) communication as an example of an encrypted communication path. In addition, the server device 2000 and the first arithmetic processing device 500 may perform communication using a dedicated line such as a VPN (Virtual Private Network) line. For example, the server apparatus 2000 and the communication module 1051 may be connected by a dedicated line such as a VPN line, and data may be transmitted / received through the dedicated line. For example, a dedicated line such as a VPN line may be provided by a wireless communication network corresponding to the SIM 1052.

<Example 1 of communication method>
An example 1 of the communication method according to the present embodiment will be described with reference to FIG. FIG. 10 is a sequence chart showing Example 1 of the communication method according to the present embodiment.

  In FIG. 10, the server device 2000 stores the master key Master_Secret in the storage unit 12 in advance. The second arithmetic processing device 600 stores the master key Master_Secret in the storage unit 602 in advance. The master key Master_Secret stored in the storage unit 12 by the server apparatus 2000 is the same as the master key Master_Secret stored in the storage unit 602 by the second arithmetic processing apparatus 600. The storage unit 12 corresponds to a server master key storage unit. The storage unit 602 corresponds to a communication device master key storage unit.

  In the SIM 1052 as an example of the second arithmetic processing unit 600, for example, a master key Master_Secret is stored in the SIM 1052 at the manufacturing factory of the SIM 1052. Alternatively, the master key Master_Secret may be stored in the SIM 1052 at a communication module 1051 or a manufacturing factory of a communication device in which the communication module 1051 is mounted.

  The communication method example 1 includes a production or installation stage (production installation phase) of the communication apparatus 1001 and a general operation stage (market operation phase) of the communication apparatus 1001.

(Production installation phase)
The production installation phase of communication method example 1 will be described. The production installation phase is performed when the communication device 1001 is produced or when the communication device 1001 is installed.

(Step S1) The first arithmetic processing unit 500 acquires the communication device correspondence identifier UNID of the communication device 1001. The communication device correspondence identifier UNID of the communication device 1001 may be stored in the first arithmetic processing device 500 in advance, or the communication device correspondence identifier UNID may be notified to the first arithmetic processing device 500 from the outside at a predetermined opportunity. Good.

  For example, the first arithmetic processing device 500 may acquire the communication device correspondence identifier UNID held by the communication device 1001.

  Alternatively, the communication device correspondence identifier UNID of the communication device 1001 may be supplied to the first arithmetic processing device 500, for example, the communication device correspondence identifier UNID managed by the manufacturer or the dealer of the communication device 1001. For example, the manufacturer of the communication device 1001 may include a communication device correspondence identifier database, and the first arithmetic processing device 500 may be notified of the communication device correspondence identifier UNID of the communication device 1001 by communication from the database.

(Step S2) The identifier notification unit 504 of the first arithmetic processing device 500 notifies the second arithmetic processing device 600 of the communication device corresponding identifier UNID of the communication device 1001.

(Step S3) The key generation unit 601 of the second arithmetic processing device 600 includes the master key Master_Secret stored in the storage unit 602, the communication device corresponding identifier UNID of the communication device 1001 notified from the first arithmetic processing device 500, the key A MAC key K_mac_gen and an ENC key K_enc_gen are generated using the type identifiers Key_ID (mac) and Key_ID (enc). The example of the key generation method mentioned above is applied to this key generation method. The key generation function is set in the key generation unit 601 in advance. The key type identifiers Key_ID (mac) and Key_ID (enc) are set in the key generation unit 601 in advance. The key generation unit 601 corresponds to a communication device key generation unit.

The key generation unit 601 uses a key generation function example 1 “Common Key = Digest (Master_Secret, UNID, Key_ID (Nk))” as an example of a key generation function,
MAC key K_mac_gen = digest (Master_Secret, UNID, Key_ID (mac)),
ENC key K_enc_gen = digest (Master_Secret, UNID, Key_ID (enc)),
Thus, the MAC key K_mac_gen and the ENC key K_enc_gen are generated. Here, the digest value is, for example, a value calculated by a hash function.

  The storage unit 602 stores a MAC key K_mac_gen and an ENC key K_enc_gen. In the communication method example 1, the storage unit 602 corresponds to a communication device key storage unit.

  Note that the second arithmetic processing unit 600 may delete the master key Master_Secret from the storage unit 602 after generating the MAC key K_mac_gen and the ENC key K_enc_gen. Thereby, the possibility that the master key Master_Secret is leaked can be reduced.

  The above is the description of the production installation phase of the communication method example 1.

(Market operation phase)
The market operation phase of communication method example 1 will be described. The market operation phase is performed at the general operation stage of the communication apparatus 1001, for example, when the communication apparatus 1001 is turned on, or when communication between the communication apparatus 1001 and the server apparatus 2000 is started.

(Step S11) The first arithmetic processing unit 500 transmits the communication device corresponding identifier UNID and the challenge (random number c) of the communication device 1001 to the server device 2000. The first arithmetic processing unit 500 generates a random number c and uses the random number c for a challenge. The first arithmetic processing unit 500 holds the challenge (random number c).

(Step S12) The key generation unit 15 of the server device 2000 includes the master key Master_Secret stored in the storage unit 12, the communication device correspondence identifier UNID of the communication device 1001 received from the first arithmetic processing device 500, and the key type identifier Key_ID ( mac), Key_ID (enc), and generates a MAC key K_mac_gen and an ENC key K_enc_gen. This key generation method is the same as the key generation method of the key generation unit 601 of the second arithmetic processing device 600 in step S3 described above. The key generation function is set in the key generation unit 15 in advance. The key type identifiers Key_ID (mac) and Key_ID (enc) are set in the key generation unit 15 in advance. The key generation unit 15 corresponds to a server key generation unit.

  The storage unit 12 stores the MAC key K_mac_gen and the ENC key K_enc_gen in association with the communication device correspondence identifier UNID of the communication device 1001. The storage unit 12 corresponds to a server key storage unit.

(Step S <b> 13) The authentication processing unit 18 of the server device 2000 uses the MAC key K_mac_gen stored in the storage unit 12 and the challenge (random number c) received from the first arithmetic processing device 500, and uses the response K_mac_gen (random number). c) is generated. This response generation method is set in the authentication processing unit 18 in advance. The response K_mac_gen (random number c) is encrypted data obtained by encrypting the random number c with the MAC key K_mac_gen as an example according to the present embodiment.

  The response K_mac_gen (random number c) may be CMAC (K_mac_gen; random number c), that is, “CMAC of random number c” generated using the MAC key K_mac_gen, as an example according to the present embodiment.

(Step S14) The authentication processing unit 18 of the server device 2000 transmits a response K_mac_gen (random number c) and a challenge (random number s) to the first arithmetic processing device 500 of the communication device 1001. The authentication processing unit 18 generates a random number s and uses the random number s for a challenge. The authentication processing unit 18 holds the challenge (random number s).

(Step S15) The first arithmetic processing unit 500 receives the challenge (random number c) transmitted to the server device 2000, the response K_mac_gen (random number c) and the challenge (random number s) received from the server device 2000, as the second arithmetic processing unit. 600.

(Step S16) The authentication processing unit 604 of the second arithmetic processing device 600 verifies the response K_mac_gen (random number c) received from the first arithmetic processing device 500. As this response verification method, a method corresponding to the response generation method in the authentication processing unit 18 of the server apparatus 2000 is set in the authentication processing unit 604 in advance. In verifying the response K_mac_gen (random number c), the authentication processing unit 604 uses the challenge (random number c) received from the first arithmetic processing unit 500 and the MAC key K_mac_gen stored in the storage unit 602.

  For example, when the response K_mac_gen (random number c) is encrypted data of the random number c using the MAC key K_mac_gen, the authentication processing unit 604 uses the MAC key K_mac_gen stored in the storage unit 602 to use the first arithmetic processing unit 500. The challenge (random number c) received from is encrypted, and the encrypted data generated by the encryption is compared with the response K_mac_gen (random number c). As a result of this comparison, if the two match, the verification of the response K_mac_gen (random number c) is passed, and if the two do not match, the verification of the response K_mac_gen (random number c) fails.

  As another verification method when the response K_mac_gen (random number c) is encrypted data of the random number c by the MAC key K_mac_gen, the authentication processing unit 604 uses the MAC key K_mac_gen stored in the storage unit 602, The response K_mac_gen (random number c) received from the first arithmetic processing unit 500 may be decrypted, and the decryption result may be compared with the challenge (random number c) received from the first arithmetic processing unit 500. As a result of this comparison, if the two match, the verification of the response K_mac_gen (random number c) is passed, and if the two do not match, the verification of the response K_mac_gen (random number c) fails.

  For example, when the response K_mac_gen (random number c) is CMAC (K_mac_gen; random number c), the authentication processing unit 604 uses the MAC key K_mac_gen stored in the storage unit 602 to receive from the first arithmetic processing unit 500. A CMAC for the challenge (random number c) is generated, and the generated CMAC is compared with the response K_mac_gen (random number c). As a result of this comparison, if the two match, the verification of the response K_mac_gen (random number c) is passed, and if the two do not match, the verification of the response K_mac_gen (random number c) fails.

  When the verification of the response K_mac_gen (random number c) is successful, the process proceeds to step S17. On the other hand, if the verification of the response K_mac_gen (random number c) fails, the process of FIG. 10 ends. If the verification of the response K_mac_gen (random number c) fails, the second arithmetic processing unit 600 may execute a predetermined error process.

(Step S17) The authentication processing unit 604 of the second processing unit 600 uses the MAC key K_mac_gen stored in the storage unit 602 and the challenge (random number s) received from the first processing unit 500 to respond. K_mac_gen (random number s) is generated. This response generation method is set in the authentication processing unit 604 in advance. The response K_mac_gen (random number s) is encrypted data obtained by encrypting the random number s with the MAC key K_mac_gen as an example according to the present embodiment.

  The response K_mac_gen (random number s) may be CMAC (K_mac_gen; random number s), that is, “CMAC of random number s” generated using the MAC key K_mac_gen, as an example according to the present embodiment.

(Step S <b> 18) The authentication processing unit 604 of the second arithmetic processing device 600 transmits a response K_mac_gen (random number s) to the first arithmetic processing device 500.

(Step S19) The first arithmetic processing unit 500 transmits the response K_mac_gen (random number s) received from the second arithmetic processing unit 600 to the server apparatus 2000.

(Step S20) The authentication processing unit 18 of the server device 2000 verifies the response K_mac_gen (random number s) received from the first arithmetic processing device 500 of the communication device 1001. As this response verification method, a method corresponding to the response generation method in the authentication processing unit 604 of the second arithmetic processing device 600 of the communication device 1001 is set in the authentication processing unit 18 in advance. In verifying the response K_mac_gen (random number s), the authentication processing unit 18 uses the challenge (random number s) transmitted to the first arithmetic processing unit 500 of the communication device 1001 and the MAC key K_mac_gen stored in the storage unit 12. To do.

  For example, when the response K_mac_gen (random number s) is encrypted data of the random number s by the MAC key K_mac_gen, the authentication processing unit 18 uses the MAC key K_mac_gen stored in the storage unit 12 to perform the first processing of the communication device 1001. The challenge (random number s) transmitted to the arithmetic processing unit 500 is encrypted, and the encrypted data generated by the encryption is compared with the response K_mac_gen (random number s). As a result of the comparison, if the two match, the verification of the response K_mac_gen (random number s) is passed, and if the two do not match, the verification of the response K_mac_gen (random number s) fails.

  As another verification method when the response K_mac_gen (random number s) is encrypted data of the random number s by the MAC key K_mac_gen, the authentication processing unit 18 uses the MAC key K_mac_gen stored in the storage unit 12, The response K_mac_gen (random number s) received from the first arithmetic processing unit 500 of the communication device 1001 may be decrypted, and the decryption result may be compared with the challenge (random number s) transmitted to the first arithmetic processing unit 500. As a result of the comparison, if the two match, the verification of the response K_mac_gen (random number s) is passed, and if the two do not match, the verification of the response K_mac_gen (random number s) fails.

  For example, when the response K_mac_gen (random number s) is CMAC (K_mac_gen; random number s), the authentication processing unit 18 uses the MAC key K_mac_gen stored in the storage unit 12 to perform the first arithmetic processing unit of the communication device 1001. The CMAC of the challenge (random number s) transmitted to 500 is generated, and the generated CMAC is compared with the response K_mac_gen (random number s). As a result of the comparison, if the two match, the verification of the response K_mac_gen (random number s) is passed, and if the two do not match, the verification of the response K_mac_gen (random number s) fails.

  If the verification of the response K_mac_gen (random number s) is successful, the process proceeds to step S21. On the other hand, if the verification of the response K_mac_gen (random number s) fails, the process of FIG. If the verification of the response K_mac_gen (random number s) fails, the server apparatus 2000 may execute a predetermined error process.

  The authentication processing unit 18 of the server device 2000 corresponds to a server authentication processing unit. The authentication processing unit 604 of the second arithmetic processing device 600 of the communication device 1001 corresponds to the communication device authentication processing unit.

(Step S21) The key transmission / reception unit 16 of the server apparatus 2000 generates a session key K_com. For example, the key transmission / reception unit 16 may generate a random number and generate a session key K_com based on the random number. The storage unit 12 stores the session key K_com in association with the communication device correspondence identifier UNID of the communication device 1001. Session key K_com corresponds to the third key.

(Step S22) The key transmission / reception unit 16 of the server apparatus 2000 encrypts the session key K_com using the ENC key K_enc_gen stored in the storage unit 12, and generates an encrypted session key K_enc_gen (K_com). The key transmission / reception unit 16 transmits the encrypted session key K_enc_gen (K_com) to the first arithmetic processing device 500 of the communication device 1001.

(Step S23) The first arithmetic processing unit 500 transmits the encrypted session key K_enc_gen (K_com) received from the server apparatus 2000 to the second arithmetic processing unit 600.

(Step S24) The key transmission / reception unit 603 of the second arithmetic processing device 600 decrypts the encrypted session key K_enc_gen (K_com) received from the first arithmetic processing device 500 with the ENC key K_enc_gen stored in the storage unit 602. As a result of this decryption, a session key K_com is acquired. Thereby, the server apparatus 2000 and the communication apparatus 1001 hold the same session key K_com.

(Step S <b> 25) The key transmission / reception unit 603 of the second arithmetic processing device 600 transmits the session key K_com to the first arithmetic processing device 500. The storage unit 502 of the first arithmetic processing device 500 stores the session key K_com received from the second arithmetic processing device 600.

  In Example 1 of the communication method, the key transmission / reception unit 603 of the second arithmetic processing device 600 of the communication device 1001 corresponds to the communication device key transmission / reception unit. The key transmission / reception unit 16 of the server apparatus 2000 corresponds to the server key transmission / reception unit.

(Step S26) The communication unit 11 of the server device 2000 and the communication unit 501 of the first arithmetic processing device 500 of the communication device 1001 perform cryptographic communication using the session key K_com. In this encrypted communication, encrypted data K_com (data) obtained by encrypting data using the session key K_com is transmitted to the communication unit 11 of the server device 2000 and the communication unit 501 of the first arithmetic processing device 500 of the communication device 1001. To and from. Thereby, an encrypted communication path using the session key K_com is constructed between the communication unit 11 of the server device 2000 and the communication unit 501 of the first arithmetic processing device 500 of the communication device 1001.

  The communication unit 11 of the server device 2000 corresponds to the server communication unit. The communication unit 501 of the first arithmetic processing device 500 of the communication device 1001 corresponds to the communication device communication unit.

  Note that the key transmission / reception unit 603 of the second arithmetic processing device 600 of the communication device 1001 may generate the session key K_com and supply it to the server device 2000.

  The above is the description of the market operation phase of the communication method example 1.

  According to the communication method example 1 described above, the server device 2000 and the second arithmetic processing device 600 of the communication device 1001 perform the authentication process using the MAC key K_mac_gen (first key) and perform the ENC key K_enc_gen (first). The session key K_com (third key) is transmitted and received by encrypted communication using (two keys). This improves the security of the session key K_com (third key) used for encrypted communication between the server device 2000 and the first arithmetic processing device 500 of the communication device 1001. This has the effect of improving safety when the communication device 1001 communicates with the external server device 2000.

  Further, the MAC key K_mac_gen (first key) used for the authentication process between the server device 2000 and the communication device 1001 is stored in the second arithmetic processing device 600 that is a secure element in the communication device 1001. Thereby, the reliability of the authentication between the server apparatus 2000 and the communication apparatus 1001 can be improved.

<Example 2 of communication method>
Example 2 of the communication method according to the present embodiment will be described with reference to FIG. FIG. 11 is a sequence chart showing Example 2 of the communication method according to the present embodiment. In FIG. 11, parts corresponding to the respective steps in FIG. 10 are denoted by the same reference numerals.

  In FIG. 11, the server apparatus 2000 stores a master key Master_Secret in the storage unit 12 in advance. The second arithmetic processing device 600 stores the master key Master_Secret in the storage unit 602 in advance. The master key Master_Secret stored in the storage unit 12 by the server apparatus 2000 is the same as the master key Master_Secret stored in the storage unit 602 by the second arithmetic processing apparatus 600. The storage unit 12 corresponds to a server master key storage unit. In the communication method example 2, the storage unit 602 corresponds to a communication device master key storage unit and a second communication device key storage unit.

  In the SIM 1052 as an example of the second arithmetic processing unit 600, for example, a master key Master_Secret is stored in the SIM 1052 at the manufacturing factory of the SIM 1052. Alternatively, the master key Master_Secret may be stored in the SIM 1052 at a communication module 1051 or a manufacturing factory of a communication device in which the communication module 1051 is mounted.

  Similar to the communication method example 1, the communication method example 2 includes a production installation phase and a market operation phase.

(Production installation phase)
The production installation phase of communication method example 2 will be described. In the production installation phase of the communication method example 2, step S1, step S2, and step S3 are executed. Steps S1, S2, and S3 are the same as those in the communication method example 1. Step S4 is then executed.

(Step S4) The second arithmetic processing unit 600 transmits the ENC key K_enc_gen to the first arithmetic processing unit 500. The storage unit 502 of the first arithmetic processing device 500 stores the ENC key K_enc_gen received from the second arithmetic processing device 600. In communication method example 2, the storage unit 502 corresponds to a first communication device key storage unit.

  The above is the description of the production installation phase of the communication method example 2.

(Market operation phase)
The market operation phase of the communication method example 2 will be described. In the market operation phase of the communication method example 2, steps S11 to S22 are executed. Steps S11 to S22 are the same as those in the communication method example 1.

(Step S24a) The key transmission / reception unit 503 of the first arithmetic processing device 500 decrypts the encrypted session key K_enc_gen (K_com) received from the server device 2000 with the ENC key K_enc_gen stored in the storage unit 502. As a result of this decryption, a session key K_com is acquired. Thereby, the server apparatus 2000 and the communication apparatus 1001 hold the same session key K_com. The storage unit 502 of the first arithmetic processing device 500 stores a session key K_com.

  In Example 2 of the communication method, the key transmission / reception unit 503 of the first arithmetic processing device 500 of the communication device 1001 corresponds to the communication device key transmission / reception unit. The key transmission / reception unit 16 of the server apparatus 2000 corresponds to the server key transmission / reception unit.

  The key transmission / reception unit 503 of the first arithmetic processing device 500 of the communication device 1001 may generate the session key K_com and supply it to the server device 2000.

  Next, step S26 is executed. Step S26 is the same as Example 1 of the communication method.

  The above is the description of the market operation phase of the communication method example 2.

  According to the communication method example 2 described above, the server device 2000 and the second arithmetic processing device 600 of the communication device 1001 perform the authentication process using the MAC key K_mac_gen (first key). In addition, the server device 2000 and the first arithmetic processing device 500 of the communication device 1001 transmit and receive the session key K_com (third key) by encrypted communication using the ENC key K_enc_gen (second key). This improves the security of the session key K_com (third key) used for encrypted communication between the server device 2000 and the first arithmetic processing device 500 of the communication device 1001. This has the effect of improving safety when the communication device 1001 communicates with the external server device 2000.

  Further, the MAC key K_mac_gen (first key) used for the authentication process between the server device 2000 and the communication device 1001 is stored in the second arithmetic processing device 600 that is a secure element in the communication device 1001. Thereby, the reliability of the authentication between the server apparatus 2000 and the communication apparatus 1001 can be improved.

  An ENC key K_enc_gen (second key) used for encrypted communication between the server device 2000 and the communication device 1001 is stored in the first arithmetic processing device 500 in the communication device 1001. The first arithmetic processing unit 500 that is not limited to a secure element can improve the communication speed of encryption communication between the server apparatus 2000 and the communication apparatus 1001 by using a CPU with relatively high processing capability.

<Example 3 of communication method>
An example 3 of the communication method according to the present embodiment will be described with reference to FIG. FIG. 12 is a sequence chart showing Example 3 of the communication method according to the present embodiment. In FIG. 12, portions corresponding to the respective steps in FIG. 10 are denoted with the same reference numerals.

  Similar to communication method example 1, communication method example 3 includes a production installation phase and a market operation phase. In the communication method example 3, the server apparatus 2000 generates a key in the production installation phase. Hereinafter, differences from the communication method example 1 will be mainly described.

  The server apparatus 2000 and the second arithmetic processing apparatus 600 store the same master key Master_Secret in advance as in the communication method example 1.

(Production installation phase)
The production installation phase of communication method example 3 will be described. In the production installation phase of the communication method example 3, step S1, step S2, and step S3 are executed. Steps S1, S2, and S3 are the same as those in the communication method example 1. Step S2a is also executed.

(Step S <b> 2 a) The identifier notifying unit 504 of the first arithmetic processing device 500 transmits the communication device corresponding identifier UNID of the communication device 1001 to the server device 2000. In the communication method example 3, the identifier notification unit 504 corresponds to a communication device-compatible identifier notification unit.

  Step S12 is then executed. The step S12 is the same as the step S12 in the market operation phase of the communication method example 1. The storage unit 12 of the server device 2000 stores the MAC key K_mac_gen and the ENC key K_enc_gen in association with the communication device correspondence identifier UNID of the communication device 1001.

  The above is the description of the production installation phase of the communication method example 3.

(Market operation phase)
The market operation phase of the communication method example 3 will be described. In the market operation phase of the communication method example 3, steps S11 and S13 to S26 are executed. Steps S11 and S13 to S26 are the same as those of the communication method example 1.

  Note that, similarly to Example 1 of the communication method, the key transmission / reception unit 603 of the second arithmetic processing device 600 of the communication device 1001 may generate the session key K_com and supply it to the server device 2000.

  The above is the description of the market operation phase of the communication method example 3.

  According to the communication method example 3 described above, the server device 2000 and the second arithmetic processing device 600 of the communication device 1001 perform the authentication process using the MAC key K_mac_gen (first key), and the ENC key K_enc_gen (first). The session key K_com (third key) is transmitted and received by encrypted communication using (two keys). This improves the security of the session key K_com (third key) used for encrypted communication between the server device 2000 and the first arithmetic processing device 500 of the communication device 1001. This has the effect of improving safety when the communication device 1001 communicates with the external server device 2000.

  Further, according to the communication method example 3, the server device 2000 generates the MAC key K_mac_gen (first key) and the ENC key K_enc_gen (second key) in the production installation phase. Thereby, the processing time in the market operation phase can be shortened.

  Further, the MAC key K_mac_gen (first key) used for the authentication process between the server device 2000 and the communication device 1001 is stored in the second arithmetic processing device 600 that is a secure element in the communication device 1001. Thereby, the reliability of the authentication between the server apparatus 2000 and the communication apparatus 1001 can be improved.

<Example 4 of communication method>
Example 4 of the communication method according to the present embodiment will be described with reference to FIG. FIG. 13 is a sequence chart illustrating Example 4 of the communication method according to the present embodiment. In FIG. 13, portions corresponding to the respective steps in FIG. 11 are denoted by the same reference numerals.

  Similar to the communication method example 2, the communication method example 4 includes a production installation phase and a market operation phase. In the communication method example 4, as in the communication method example 3, the server device 2000 generates a key in the production installation phase. Hereinafter, differences from the communication method example 2 will be mainly described.

  The server device 2000 and the second arithmetic processing device 600 store the same master key Master_Secret in advance as in the communication method example 2.

(Production installation phase)
The production installation phase of communication method example 4 will be described. In the production installation phase of the communication method example 4, step S1, step S2, step S3 and step S4 are executed. Steps S1, S2, S3, and S4 are the same as those in the second example of the communication method. Moreover, step S2a and step S12 are performed. Steps S2a and S12 are the same as those in the communication method example 3. The storage unit 12 of the server device 2000 stores the MAC key K_mac_gen and the ENC key K_enc_gen in association with the communication device correspondence identifier UNID of the communication device 1001.

  The above is the description of the production installation phase of the communication method example 4.

(Market operation phase)
The market operation phase of the communication method example 4 will be described. In the market operation phase of communication method example 4, step S11, steps S13 to S22, step S24a, and step S26 are executed. Step S11, step S13 to step S22, and step S26 are the same as in the communication method example 1. Step S24a is the same as Example 2 of the communication method.

  Similar to the second example of the communication method, the key transmission / reception unit 503 of the first arithmetic processing device 500 of the communication device 1001 may generate the session key K_com and supply it to the server device 2000.

  The above is the description of the market operation phase of the communication method example 4.

  According to the communication method example 4 described above, the server device 2000 and the second arithmetic processing device 600 of the communication device 1001 perform the authentication process using the MAC key K_mac_gen (first key). In addition, the server device 2000 and the first arithmetic processing device 500 of the communication device 1001 transmit and receive the session key K_com (third key) by encrypted communication using the ENC key K_enc_gen (second key). This improves the security of the session key K_com (third key) used for encrypted communication between the server device 2000 and the first arithmetic processing device 500 of the communication device 1001. This has the effect of improving safety when the communication device 1001 communicates with the external server device 2000.

  Further, according to the communication method example 4, the server apparatus 2000 generates the MAC key K_mac_gen (first key) and the ENC key K_enc_gen (second key) in the production installation phase. Thereby, the processing time in the market operation phase can be shortened.

  Further, the MAC key K_mac_gen (first key) used for the authentication process between the server device 2000 and the communication device 1001 is stored in the second arithmetic processing device 600 that is a secure element in the communication device 1001. Thereby, the reliability of the authentication between the server apparatus 2000 and the communication apparatus 1001 can be improved.

  An ENC key K_enc_gen (second key) used for encrypted communication between the server device 2000 and the communication device 1001 is stored in the first arithmetic processing device 500 in the communication device 1001. The first arithmetic processing unit 500 that is not limited to a secure element can improve the communication speed of encryption communication between the server apparatus 2000 and the communication apparatus 1001 by using a CPU with relatively high processing capability.

  The embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration is not limited to this embodiment, and includes design changes and the like within a scope not departing from the gist of the present invention.

  When the IMSI or ICCID is used as an example of the communication device correspondence identifier, for example, when the communication device correspondence identifier is IMSI, the SIM 1052 may use the MAC key K_mac_gen and ENC at an arbitrary timing after the IMSI is stored. The key K_enc_gen may be generated, and the generated MAC key K_mac_gen and ENC key K_enc_gen may be held. For example, when the SIM 1052 is manufactured, the IMSI may be written in the SIM 1052, and the SIM 1052 may generate and hold the MAC key K_mac_gen and the ENC key K_enc_gen.

  When IMSI or ICCID is used as an example of the communication device correspondence identifier, for example, when the communication device correspondence identifier is IMSI, the SIM 1052 notifies the first arithmetic processing device 500 of its own IMSI. The identifier notification unit 504 of the first arithmetic processing device 500 notifies the server device 2000 of the IMSI notified from the SIM 1052.

  In addition, when IMSI or ICCID is used as an example of the communication device correspondence identifier, for example, when the communication device correspondence identifier is IMSI, when the SIM 1052 is reused by another communication device 1001, the MAC held by the SIM 1052 is retained. The key K_mac_gen and the ENC key K_enc_gen may be used in the other communication device 1001.

  In the above-described embodiment, the second arithmetic processing device 600 holds the master key Master_Secret, but the second arithmetic processing device 600 may not hold the master key Master_Secret. The second processing unit 600 may hold the MAC key K_mac_gen and the ENC key K_enc_gen generated externally without holding the master key Master_Secret. For example, when the SIM 1052 is used as the second arithmetic processing device 600, the key generation device at the manufacturing factory of the SIM 1052 holds the same master key Master_Secret as the server device 2000. The key generation device generates a MAC key K_mac_gen and an ENC key K_enc_gen using the master key Master_Secret, and writes the generated MAC key K_mac_gen and ENC key K_enc_gen in the SIM 1052. In this case, the IMSI or ICCID of the SIM 1052 may be used as the communication device correspondence identifier.

  When the first arithmetic processing unit 500 includes a debug port such as JTAG (Joint Test Action Group), an authentication function using an ID (identifier) may be provided for the debug port. Thereby, it is possible to suppress the leakage of the session key K_com due to an attack such as a memory dump or a tapping attack on the first arithmetic processing unit 500. For example, an ID authentication function may be provided for the debug port of the IoT device 1040 or the communication gateway device 1050.

In addition, a computer program for realizing the functions of each device described above may be recorded on a computer-readable recording medium, and the program recorded on the recording medium may be read into a computer system and executed. Here, the “computer system” may include an OS and hardware such as peripheral devices.
“Computer-readable recording medium” refers to a flexible disk, a magneto-optical disk, a ROM, a writable nonvolatile memory such as a flash memory, a portable medium such as a DVD (Digital Versatile Disc), and a built-in computer system. A storage device such as a hard disk.

Further, the “computer-readable recording medium” means a volatile memory (for example, DRAM (Dynamic DRAM) in a computer system that becomes a server or a client when a program is transmitted through a network such as the Internet or a communication line such as a telephone line. Random Access Memory)), etc., which hold programs for a certain period of time.
The program may be transmitted from a computer system storing the program in a storage device or the like to another computer system via a transmission medium or by a transmission wave in the transmission medium. Here, the “transmission medium” for transmitting the program refers to a medium having a function of transmitting information, such as a network (communication network) such as the Internet or a communication line (communication line) such as a telephone line.
The program may be for realizing a part of the functions described above. Furthermore, what can implement | achieve the function mentioned above in combination with the program already recorded on the computer system, and what is called a difference file (difference program) may be sufficient.

1, 2, 3 ... communication system 11, 501 ... communication unit 12, 112, 212, 502, 602, 1054 ... storage unit, 15, 601 ... key generation unit, 16, 503, 603 ... key transmission / reception unit, 18 , 604 ... Authentication processing unit, 110, 210, 1053 ... CPU, 116, 216, 1055 ... Interface unit, 504 ... Identifier notification unit, 1001 ... Communication device, 1040 ... IoT device, 1050 ... Communication gateway device, 1051 ... Communication module , 1052 ... SIM, 2000 ... server device, 3000 ... communication network, 3010 ... communication path

Claims (13)

A communication system that performs communication between a communication device and a server device,
The server device; a first arithmetic processing device mounted on the communication device; and a second arithmetic processing device that is a secure element mounted on the communication device;
The second arithmetic processing unit includes:
A communication device key storage unit for storing a first key and a second key used for communication between the communication device and the server device;
A communication device authentication processing unit that performs authentication processing with the server device using the first key;
A communication device key transmission / reception unit that transmits or receives a third key to and from the server device by encrypted communication using the second key;
The first arithmetic processing unit includes a communication device communication unit that performs cryptographic communication with the server device using the third key,
The server device
A server key storage unit for storing the same first key and the second key as the communication device;
A server authentication processing unit that performs authentication processing with the communication device authentication processing unit of the communication device using the first key;
A server key transmission / reception unit that transmits or receives the third key to / from the communication device key transmission / reception unit of the communication device by encrypted communication using the second key;
A server communication unit that performs cryptographic communication with the communication device communication unit of the communication device using the third key,
Communications system. A communication system that performs communication between a communication device and a server device,
The server device; a first arithmetic processing device mounted on the communication device; and a second arithmetic processing device that is a secure element mounted on the communication device;
The second arithmetic processing unit includes:
A second communication device key storage unit that stores a first key used for communication between the communication device and the server device;
A communication device authentication processing unit that performs authentication processing with the server device using the first key,
The first arithmetic processing unit includes:
A first communication device key storage unit that stores a second key used for communication between the communication device and the server device;
A communication device key transmission / reception unit that transmits or receives a third key to and from the server device by encrypted communication using the second key;
A communication device communication unit that performs cryptographic communication with the server device using the third key;
The server device
A server key storage unit for storing the same first key and the second key as the communication device;
A server authentication processing unit that performs authentication processing with the communication device authentication processing unit of the communication device using the first key;
A server key transmission / reception unit that transmits or receives the third key to / from the communication device key transmission / reception unit of the communication device by encrypted communication using the second key;
A server communication unit that performs cryptographic communication with the communication device communication unit of the communication device using the third key,
Communications system. The second arithmetic processing unit includes:
A communication device master key storage unit for storing a master key;
A communication device key generation unit that generates the first key and the second key using the master key and a communication device correspondence identifier corresponding to the communication device;
The communication system according to claim 1, further comprising: The server device
A server master key storage unit that stores the same master key as the communication device;
A server key generation unit that generates the first key and the second key using the master key and a communication device correspondence identifier corresponding to the communication device;
The communication system according to any one of claims 1 to 3, further comprising: The first arithmetic processing unit is configured to notify the communication device correspondence identifier to the second arithmetic processing device and the server device;
The communication system according to any one of claims 3 and 4, further comprising: A communication device that communicates with the server device,
A first arithmetic processing unit and a second arithmetic processing unit that is a secure element;
The second arithmetic processing unit includes:
A communication device key storage unit for storing a first key and a second key used for communication between the communication device and the server device;
A communication device authentication processing unit that performs authentication processing with the server device using the first key;
A communication device key transmission / reception unit that transmits or receives a third key to and from the server device by encrypted communication using the second key;
The first arithmetic processing unit includes a communication device communication unit that performs cryptographic communication with the server device using the third key.
Communication device. A communication device that communicates with the server device,
A first arithmetic processing unit and a second arithmetic processing unit that is a secure element;
The second arithmetic processing unit includes:
A second communication device key storage unit that stores a first key used for communication between the communication device and the server device;
A communication device authentication processing unit that performs authentication processing with the server device using the first key,
The first arithmetic processing unit includes:
A first communication device key storage unit that stores a second key used for communication between the communication device and the server device;
A communication device key transmission / reception unit that transmits or receives a third key to and from the server device by encrypted communication using the second key;
A communication device communication unit that performs cryptographic communication with the server device using the third key,
Communication device. A server device that communicates with a communication device;
A server key storage unit for storing the same first key and second key as the communication device;
A server authentication processing unit that performs an authentication process with a communication device authentication processing unit of a second arithmetic processing device that is a secure element of the communication device using the first key;
A server key transmission / reception unit that transmits or receives a third key to / from a communication device key transmission / reception unit of the communication device by encrypted communication using the second key;
A server communication unit that performs cryptographic communication with the communication device communication unit of the communication device using the third key;
A server device comprising: A communication method between a communication device and a server device,
The communication device includes a first arithmetic processing device and a second arithmetic processing device which is a secure element,
A key storage step in which the second arithmetic processing device stores a first key and a second key used for communication between the communication device and the server device;
An authentication processing step in which the second arithmetic processing device performs an authentication process with the server device using the first key;
A key sending / receiving step in which the second processing unit sends or receives a third key to and from the server device by encrypted communication using the second key;
A communication step in which the first arithmetic processing device performs cryptographic communication with the server device using the third key;
Including a communication method. A communication method between a communication device and a server device,
The communication device includes a first arithmetic processing device and a second arithmetic processing device which is a secure element,
A first key storage step in which the second arithmetic processing unit stores a first key used for communication between the communication device and the server device;
An authentication processing step in which the second arithmetic processing device performs an authentication process with the server device using the first key;
A second key storage step in which the first arithmetic processing unit stores a second key used for communication between the communication device and the server device;
A key sending / receiving step in which the first processing unit sends or receives a third key to and from the server device by encrypted communication using the second key;
A communication step in which the first arithmetic processing device performs cryptographic communication with the server device using the third key;
Including a communication method. A second computer, which is a secure element, provided in a communication device that communicates with a server device,
A communication device key storage function for storing a first key and a second key used for communication between the communication device and the server device;
A communication device authentication processing function for performing authentication processing with the server device using the first key;
A communication device key transmission / reception function for transmitting or receiving a third key to / from the server device by encrypted communication using the second key;
A computer program for causing a first computer included in the communication device to realize a communication device communication function for performing cryptographic communication with the server device using the third key. A second computer, which is a secure element, provided in a communication device that communicates with a server device,
A second communication device key storage function for storing a first key used for communication between the communication device and the server device;
A communication device authentication processing function for performing authentication processing with the server device using the first key;
A first computer provided in the communication device;
A first communication device key storage function for storing a second key used for communication between the communication device and the server device;
A communication device key transmission / reception function for transmitting or receiving a third key to / from the server device by encrypted communication using the second key;
A computer program for realizing a communication device communication function for performing cryptographic communication with the server device using the third key. In the server computer that communicates with the communication device,
A server key storage function for storing the same first key and second key as the communication device;
A server authentication processing function for performing authentication processing with a communication device authentication processing unit of a second arithmetic processing device which is a secure element of the communication device using the first key;
A server key transmission / reception function for transmitting or receiving a third key to / from a communication device key transmission / reception unit of the communication device by encrypted communication using the second key;
A server communication function for performing cryptographic communication with the communication device communication unit of the communication device using the third key;
Computer program for realizing.

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