JP2009060528A - Key setting method and key setting system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a key setting method capable of preventing an operation key generated by a plurality of service providers from being viewed by anyone other than the service provider and authenticating the issuer of the operation key.
A terminal manufacturer server 5 writes a secret key SK1 and a common key CK2 in a SAM 4, and writes a public key PK1 and a common key CK2 in a terminal 2. The terminal manufacturer hands over the SAM 4 to the service provider. The service provider server 3 encrypts the operation key K by using the common key CK2 in the SAM 4 and gives a signature by the secret key SK1 to the encrypted operation key, thereby encrypting the operation key E [CK2, K ] Is generated. The service providing server 3 writes the encryption operation key E [CK2, K] into the terminal 2 via the information setter server 1. The terminal 2 verifies the signature using the public key PK1, and decrypts the encryption operation key E [CK2, K] with the common key CK2.
[Selection] Figure 1

Description

  The present invention relates to a key setting method for setting a key used for encryption processing in a terminal device or the like.

  When information such as a key is set in a terminal device such as a payment terminal, it is necessary to prevent leakage of the information to the outside. Patent Document 1 discloses an invention of an IC card issue system that encrypts IC card issue information and sets the information in the IC card. In the invention of Patent Document 1, IC card issuance information is generated and encrypted on a storage medium provided with encryption means, and the encrypted key is written into the IC card. The IC card decrypts the encrypted IC card issue information and stores it in the memory. Thereby, the IC card issuance information generated in the storage medium can be stored in the IC card without being exposed to the outside.

Patent Document 2 discloses an issuing device that writes an encryption key to an IC card while ensuring security. In the invention of Patent Document 2, an encryption key is generated on the SAM (Secure Application Module) side, the encryption key is delivered from the SAM to the IC card, and the encryption key is decrypted by the IC card.
JP-A 64-081084 Japanese Patent No. 3868519

  By the way, in a terminal device such as a payment terminal, for example, a plurality of different service providers may set operation keys corresponding to services in the terminal device. In this case, it is assumed that the service provider that provides the operation key differs from the information setter who sets the operation key in the terminal device.

  However, in the IC card issuing device described in Patent Document 1 described above, the issuer independently generates and sets IC card issue information. Also in the invention of Patent Document 2, it is not assumed that an operation key provided by a plurality of service providers is set by an information setter different from the service provider. Further, in the invention of Patent Document 1, there is no mechanism for proving whether or not the IC card issue information set in the IC card is information generated by a true issuer.

  The present invention has been made in view of the above circumstances, and is configured to prevent operation keys generated by a plurality of service providers from being viewed by anyone other than the service provider and to authenticate the issuer of the operation key It aims to provide a method.

  The key setting method of the present invention is a key setting method for writing an operation key necessary for execution of an application to a terminal, in which the terminal manufacturer's server corresponds to the first public key and the first public key. Generating a first secret key, a second encryption key, writing the first secret key and the second encryption key into a cryptographic operation device, and the first public key and the second encryption key. And the service provider server executes the step of generating the operation key and the step of writing the operation key to the cryptographic operation device, and the cryptographic operation device Encrypting the operation key using the second encryption key, signing the encrypted operation key using the first secret key, and outputting the encrypted operation key and its signature value Service provider support At least one of a server and an information setter server executes the step of transmitting the encrypted operation key and its signature value to the terminal, and the terminal sends the signature value of the operation key to the first And the step of decrypting the operation key with the second encryption key.

  With this configuration, a common key is set for both the cryptographic operation device and the terminal, and operation keys generated by a plurality of service provider servers are encrypted by the cryptographic operation device and transferred to the terminal. Since the terminal decrypts the operation key inside the terminal using the common key set in the terminal manufacturer server, it is possible to prevent leakage of the operation key when setting the operation key in the terminal. Also, a secret key is set in the cryptographic operation device, a public key is set in the terminal, and an electronic signature using the secret key is assigned to the operation key. The terminal can authenticate whether or not the operation key is provided by the true service provider by verifying the electronic signature using the public key.

  The key setting method of the present invention uses a SAM (Secure Application Module) as the cryptographic operation device.

  With this configuration, it is possible to prevent leakage of key information at the stage of transport of encryption and signature keys from the terminal manufacturer to the service provider and use of the keys by the service provider. The SAM may be a portable SAM that is convenient to carry.

  The key setting system of the present invention includes a terminal, a terminal manufacturer server of a terminal manufacturer that manufactures the terminal, a service provider server of a service provider that provides a service through the terminal, and an application provided by the service provider The information setter server of the information setter who sets the operation key necessary for the execution of the terminal, and a cryptographic operation device for encrypting the operation key, the terminal manufacturer server, A first public key, a first secret key corresponding to the first public key, a key generation unit that generates a second encryption key, and a cryptographic operation on the first secret key and the second encryption key A data input / output unit that writes to the device and writes the first public key and the second encryption key to the terminal, the service provider server includes an operation key generation unit that generates an operation key, and the cryptographic operation apparatus A data input / output unit that writes the operation key and reads the encrypted operation key and its signature value from the cryptographic operation device, and transmits the encrypted operation key and its signature value to the information setter server A key management unit that encrypts the operation key using the second encryption key and signs the encrypted operation key using the first secret key; A data input / output unit that outputs an encrypted operation key and its signature value, and the information setter server receives the encrypted operation key and its signature value received from the server of the service provider, A data transmission unit that transmits to the terminal, and the terminal includes a key management unit that verifies the signature value of the operation key with the first public key and decrypts the operation key with the second encryption key. Have a configuration.

  With this configuration, as with the key setting method of the present invention, when setting the operation key in the terminal, it is possible to prevent leakage of the operation key, and whether or not the operation key is provided by a true service provider. Can be authenticated.

  The key setting system of the present invention uses a SAM (Secure Application Module) as the cryptographic operation device.

  With this configuration, it is possible to prevent leakage of key information at the stage of transport of encryption and signature keys from the terminal manufacturer to the service provider and use of the keys by the service provider.

  According to the present invention, when setting an operation key in a terminal, it is possible to prevent leakage of the operation key, and it is possible to authenticate whether or not the operation key is provided by a true service provider. Have

  Hereinafter, a key setting system and a key setting method according to an embodiment of the present invention will be described. FIG. 1 is an explanatory diagram showing an outline of a key setting system and a key setting method according to the present embodiment. FIG. 2 is a sequence diagram showing a key setting procedure according to the present embodiment.

  As shown in FIG. 1 and FIG. 2, the key setting system of the present embodiment provides a service using the terminal manufacturer server 5 of the terminal manufacturer that manufactures and provides the terminal 2 and the SAM 4 and the terminal 2. There is a service provider server 3 of a service provider and an information setter server 1 of an information setter who sets information in the terminal 1. The information setter is, for example, an organization whose independence is guaranteed by a contract, such as a specific trust organization agreed by the terminal manufacturer or service provider, or a person who manages the operation of the terminal. Information setters are different from service providers and terminal manufacturers.

  In the following description, a pair of encryption keys in the public key encryption method is referred to as a “public key” and a “secret key”. Data encrypted using a public key or a secret key can be decrypted using a secret key or a public key corresponding to the key used for encryption. Since the sender encrypts the data using the receiver's public key and transmits the data, only the receiver having the secret key can decrypt the data, so the data can be transmitted safely. The sender can also transmit a predetermined message encrypted using his / her private key. The recipient who receives this decrypts the message using the sender's public key. If the message can be correctly decrypted, it can be confirmed that the sender has a secret key, and thus the sender can be authenticated. This mechanism is called electronic signature.

  In the following description, the encryption key in the common key encryption method is referred to as “common key”. Data encrypted using a certain common key can be decrypted using the common key.

The procedure of the key setting method according to the present embodiment will be described with reference to FIGS.
First, the terminal manufacturer server 5 generates a public key PK1 and a secret key SK1 corresponding to the public key PK1 (S10). The terminal manufacturer server 5 writes the secret key SK1 into the SAM4 (S12) and writes the public key PK1 into the terminal 2 (S14). The SAM 4 mounts the secret key SK1 transferred from the terminal manufacturer server 5 (S16). The terminal 2 mounts the public key PK1 transferred from the terminal manufacturer server 5 (S18).

  The terminal manufacturer server 5 generates a common key CK2 (S20). The terminal manufacturer server 5 writes the common key CK2 into the terminal 2 and the SAM 4 (S22, S24). The terminal 2 and the SAM 4 mount the common key CK2 transferred from the terminal manufacturer server 5 (S26, S28).

  Next, the terminal manufacturer passes the SAM 4 with the key set to the service provider, and passes the terminal 2 with the key set to the information setter.

  The service provider server 3 generates an operation key K necessary for executing the application related to the service (S30). The service provider server 3 writes the generated operation key K in the SAM 4 (S32).

  The SAM 4 encrypts the operation key K written from the service provider server 3 using the common key CK2, and generates an encrypted operation key E [CK2, K] (S34). Further, the SAM 4 gives the signature SG1 to the encryption operation key E [CK2, K] using the secret key SK1 (S36). The SAM 4 outputs the encrypted operation key E [CK2, K] with the signature SG1 to the service provider server 3 (S38).

  The service provider server 3 transmits the encrypted operation key E [CK2, K] with the signature SG1 acquired from the SAM 4 to the information setter server 1 (S40).

  The information setter server 1 transfers the encrypted operation key E [CK2, K] with the signature SG1 received from the service provider server 3 to the terminal 2 (S42).

The terminal 2 verifies the signature SG1 transferred from the information setter server 1 using the public key PK1 set in the terminal manufacturer server 5 (S44). If the verification is successful, the encrypted operation key E [CK2, K] is decrypted with the common key CK2, and the operation key K is acquired (S46). The terminal 2 sets the extracted operation key K in the terminal 2 and is ready to start operation (S48).
The key setting method of the present embodiment has been described above.

  According to the key setting method of this embodiment, the terminal manufacturer server 5 sets the common key CK2 to the terminal 2 and the SAM4, and the service provider server 3 uses the common key CK2 in the SAM4 to encrypt the operation key E. [CK2, K] is acquired. The information setter server 1 transfers the encryption operation key E [CK2, K] received from the service provider server 3 to the terminal 2, and the terminal 2 uses the common key CK2 to encrypt the operation key E [CK2, K] is decrypted and set without taking it out of the terminal 2. Thereby, when setting the operation key K to the terminal 2, it is possible to prevent leakage of the information of the operation key K.

  The secret key SK1 generated by the terminal manufacturer server 5 is set in the SAM4 and the public key PK1 is set in the terminal 2, and the service provider server 3 uses the secret key SK1 in the SAM4 to encrypt the operation key E [CK2, K]. Signature SG1 is obtained. The information setter server 1 transfers the signature SG1 received from the service provider server 3 to the terminal 2, and the terminal 2 verifies using the public key PK1, so that the operation key K set in the terminal 2 provides the service. It can be guaranteed that it was generated by a person.

  Since the control key used for setting the operation key is managed in the SAM 4, it is not necessary for the service provider or the information setter to manage, and the operation can be simplified.

  FIG. 3 is a block diagram showing an example of a key setting system according to the present embodiment. Here, as an example of a service, a payment service performed via a vending machine will be described as an example. As shown in FIG. 3, in this example, a vending machine company 60 as an information setter who sets a key in a terminal, payment providers 62a and 62b as service providers, and a terminal manufacturer 64 as a terminal manufacturer. Exists. The vending machine company 60 has a management server 10, the payment providers 62 a and 62 b have management servers 30 a and 30 b, respectively, and the terminal manufacturer server 64 has a management server 50. The management servers 10, 30a, 30b are connected to each other via a communication line 70.

  In the example of FIG. 3, the vending machine 20 is described as the terminal 2, but as the terminal 2, a POS (Point Of Sales) terminal, a payment terminal using electronic money, or a payment terminal using a credit card. For example, various terminal devices can be used.

  The management server 10 includes a data input / output unit 11, a control unit 12, and a key management unit 13. The data input / output unit 11 has a configuration capable of inputting / outputting data to / from the communication line 70 and the vending machine 20.

  The control unit 12 has a function of controlling the overall operation of the management server 10. The control unit 12 is mainly configured by a processor that operates according to a predetermined program. For example, data is acquired from the management server 30a or the like via the data input / output unit 11, and processing for transferring the received data to the key management unit 13 or processing for transferring data from the key management unit 13 to the vending machine 20 is performed. .

  The key management unit 13 manages the encrypted operation key E [CK2, K_A] to which the signature SG1_A acquired from the management server 30a of the payment provider 62a is attached. The key management unit 13 manages the encryption operation key E [CK2, K_B] to which the signature SG1_B acquired from the management server 30b of the payment provider 62b is added.

  Next, the management server 30a of the payment provider 62a will be described. The management server 30b of the payment provider 62b has basically the same configuration as the management server 30a described below except that the contents of the managed key are different. The management server 30a includes a data input / output unit 31a, a control unit 32a, a key generation unit 33a, and a key management unit 34a. The data input / output unit 31 a has a configuration capable of inputting / outputting data to / from the communication line 70 and the SAM 4. In this embodiment, there are two payment providers, but the same applies to three or more payment providers, and the present invention is suitable when there are a plurality of payment providers in this way.

  The control unit 32a has a function of controlling the overall operation of the management server 30a. The control unit 32a is mainly configured by a processor that operates according to a predetermined program. For example, processing for instructing key generation to the key generation unit 33a, processing for transferring the generated key to the SAM 4 and requesting encryption and signature assignment, processing for receiving the key processed by the SAM 4 and transferring it to the key management unit 34a, signature For example, a process of transferring the encryption key to which the key is assigned from the key management unit 34a to the management server 10 of the information setter.

  The key generation unit 33a generates and manages an operation key K_A necessary for executing the service provided by the payment provider 62a. The key management unit 34a manages the encryption operation key E [CK2, K_A] to which the signature SG1_A acquired from the SAM 4 is added.

  Next, the management server 50 of the terminal manufacturer 64 will be described. The management server 50 includes a data input / output unit 51, a control unit 52, and a key generation unit 53. The data input / output unit 51 has a configuration capable of inputting / outputting data to / from the communication line 70, the SAM 4 and the vending machine 20.

  The control unit 52 has a function of controlling the overall operation of the management server 50. The control unit 52 is mainly configured by a processor that operates according to a predetermined program. For example, processing for instructing key generation to the key generation unit 53 and processing for transferring the generated key to the SAM 4 or the vending machine 20 are performed.

  The key generation unit 53 generates a key CK2 for encrypting or decrypting the operation key K_A and the operation key K_B of the payment provider A and the payment provider B, and a secret for generating or verifying the signature SG1_A and the signature SG1_B. A key SK1 and a public key PK1 are generated and managed.

  The vending machine 20 includes a data input / output unit 21, a control unit 22, a control key management unit 23, an operation key management unit 24, a non-contact IC reader / writer (hereinafter referred to as non-contact ICR / W) 25, Is provided.

  The non-contact ICR / W 25 performs data communication by non-contact communication with a non-contact IC card in which electronic money or the like is stored. For example, the non-contact ICR / W 25 reads data from a non-contact IC card for performing electronic money settlement. In addition, you may use other interfaces, such as not only non-contact ICR / W25 but a magnetic card.

  The data input / output unit 21 has a configuration capable of inputting / outputting data to / from the management server 10 of the vending machine company 60 and the management server 50 of the terminal manufacturer 64.

  The control unit 22 has a function of controlling the operation of the entire vending machine 20. The control unit 22 is mainly configured by a processor that operates according to a predetermined program. For example, the control secret key PK_1 and the common key CK_2 are acquired from the management server 50 via the data input / output unit 21 and managed by the control key management unit 23. The control unit 22 also obtains the encryption operation key E [CK2, K_A] to which the signature SG1_A of the payment provider A obtained from the management server 10 is assigned and the encryption operation key to which the signature SG1_B of the payment provider B is assigned. E [CK2, K_B] is received, the signature is verified, the encrypted operation key is decrypted to extract the operation key, and the operation key is transferred to the operation key management unit 24. Electronic money or the like via the contactless ICR / W 25 Control of data communication by non-contact communication with the non-contact IC card in which is stored, encryption / decryption processing of data by an operation key, and the like.

  The control key management unit 23 manages the public key PK1 and the common key CK2 acquired from the management server 50 of the terminal manufacturer 64. The operation key management unit 24 manages the operation key K_A and the operation key K_B of the payment provider acquired from the management server 10.

  Note that the vending machine 20 in which the control public key PK1 and the common key CK2 are written by the management server 50 of the terminal manufacturer 64 is delivered to the vending machine company 60.

  The SAM 4 includes a data input / output unit 41, a control unit 42, and a control key management unit 43. The data input / output unit 41 has a configuration capable of inputting / outputting data to / from the management servers 30a and 30b of the payment providers 62a and 62b and the management server 50 of the terminal manufacturer 64.

  The control unit 42 has a function of controlling the overall operation of the SAM 4. The control unit 42 is mainly configured by a processor that operates according to a predetermined program. For example, the control secret key SK_1 and the common key CK_2 are acquired from the management server 50 of the terminal manufacturer 64 via the data input / output unit 41 and managed by the control key management unit 43. The control unit 42 receives the operation key K_A of the payment provider A from the management server 30a of the payment provider 62a, and uses the encrypted operation key E [CK2, K_A] and the secret key SK_1 using the common key CK2. The signature SG1_A is generated and transferred to the management server 30a of the payment provider 62a. The same processing is performed for the management server 30b of the payment provider 62b.

  The operation key management unit 43 uses the common key CK2 for encrypting the operation key K_A and the operation key K_B of the payment provider 62a and the payment provider 62b, and the secret key SK1 for generating the signature SG1_A and the signature SG1_B. to manage.

  The SAM4 in which the control secret key SK1 and the common key CK2 are written by the management server 50 of the terminal manufacturer 64 is delivered to the payment providers 62a and 62b.

  The settlement provider 62a also transfers the encrypted operation key E [CK2, K_A] to which the signature SG1_A managed by the management server 30a is assigned to the management server 10 of the vending machine company 60 via the communication line 70. Alternatively, it may be delivered to the management server 10 of the vending machine company 60 by a storage medium such as a memory card. The settlement provider 62b also transfers the encrypted operation key E [CK2, K_B] with the signature SG1_B managed by the management server 30b to the management server 10 of the vending machine company 60 via the communication line 70. Alternatively, it may be delivered to the management server 10 of the vending machine company 60 by a storage medium such as a memory card.

  The management server 10 of the vending machine company 60 transfers the encrypted operation key E [CK2, K_B] received from the management server 50 of the payment provider 62a to the vending machine 20. The vending machine 20 verifies the electronic signature of the encrypted operation key E [CK2, K_B] transferred from the management server 10, and decrypts the encrypted operation key E [CK2, K_B] when the verification result is OK. And set in the operation key management unit 24.

  According to this embodiment, even when operating keys provided by a plurality of settlement providers are set in one vending machine 20, the confidentiality of the operating key when setting the operating key is ensured. Authentication of the operation key issuer can be performed.

  Further, according to the present embodiment, it is necessary for the settlement providers 62a and 62b and the vending machine company 60 to manage the control secret key SK1, the public key PK1, and the common key CK2 used for setting the operation key. There is no, and operation can be simplified.

  Further, according to the present embodiment, by storing and delivering the control secret key SK1 and the common key CK2 in the SAM 4 where analysis of internal information is difficult, it is possible to guarantee the confidentiality of the key at the time of delivery.

  Further, according to the present embodiment, the operation secret key and the signature generation are performed by the SAM 4, so that the control secret can be maintained between the plurality of settlement providers 62 a and 62 b and the vending machine company 60. The confidentiality of the key SK1 and the common key CK2 can be guaranteed.

  As described above, according to the present invention, when setting the operation key in the terminal, it is possible to prevent the leakage of the operation key, and whether or not the operation key is provided by a true service provider. It has an excellent effect of being able to authenticate and is useful for a key setting method for a payment terminal device or the like.

Explanatory drawing which shows the outline of the key setting method which concerns on this Embodiment. The sequence diagram which shows the procedure of the key setting method which concerns on this Embodiment Block diagram showing an example of a key setting system according to the present embodiment

Explanation of symbols

1 Information Setter Server 2 Terminal 3 Service Provider Server 4 SAM
5 Terminal manufacturer server 10, 30a, 30b, 50 Management server 11, 21, 31a, 31b, 41, 51 Data input / output unit 12, 22, 32a, 32b, 42, 52 Control unit 13, 34a, 34b Key management unit 20 Vending machine 23, 43 Control key management unit 24 Operation key management unit 25 Non-contact IC R / W
33a, 33b, 53 Key generator 60 Vending machine company 62a, 62b Payment provider 64 Terminal manufacturer 70 Communication line

Claims (4)

A key setting method for writing an operation key necessary for executing an application to a terminal,
The device manufacturer's server
Generating a first public key, a first secret key corresponding to the first public key, and a second encryption key;
Writing the first secret key and the second encryption key to a cryptographic operation device;
Writing the first public key and the second encryption key to the terminal;
The server of the service provider
Generating the operational key;
Performing the step of writing the operation key to the cryptographic operation device;
The cryptographic operation device is
Encrypting the operation key using the second encryption key, signing the encrypted operation key using the first secret key, and outputting the encrypted operation key and its signature value. Run,
At least one of the server of the service provider or the server of the information setter
Performing the step of transmitting the encrypted operation key and its signature value to the terminal;
The terminal is
Verifying the signature value of the operational key with the first public key and decrypting the operational key with the second encryption key;
Key setting method to execute.   The key setting method according to claim 1, wherein a SAM (Secure Application Module) is used as the cryptographic operation device. A terminal, a terminal manufacturer server of a terminal manufacturer that manufactures the terminal, a service provider server of a service provider that provides a service through the terminal, and an operation key necessary for executing an application provided by the service provider An information setter server of an information setter to be set in the terminal, and a cryptographic operation device for encrypting the operation key,
The terminal manufacturer server is
A first public key, a first secret key corresponding to the first public key, a key generation unit for generating a second encryption key,
A data input / output unit for writing the first secret key and the second encryption key to a cryptographic operation device, and writing the first public key and the second encryption key to the terminal;
The service provider server is:
An operational key generator for generating an operational key;
A data input / output unit that writes the operational key to the cryptographic operation device and reads the encrypted operational key and its signature value from the cryptographic operation device;
A transmission unit that transmits the encrypted operation key and its signature value to the information setter server;
The cryptographic operation device is:
A key management unit that encrypts the operation key using the second encryption key and signs the encrypted operation key using the first secret key;
A data input / output unit that outputs an encrypted operation key and its signature value,
The information setter server
A data transmission unit for transmitting the encrypted operation key and the signature value received from the server of the service provider to the terminal;
The terminal
A key setting system comprising a key management unit that verifies the signature value of the operation key with the first public key and decrypts the operation key with the second encryption key.   The key setting system according to claim 3, wherein the cryptographic operation device is a SAM (Secure Application Module).

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