JP2003324420A - Cryptographic processing method and apparatus, verification method and apparatus, and operation proxy method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To make impossible even an illegal action due to a person authorized all in operation of an information system wherein cryptographic processing using a private key is used. <P>SOLUTION: In encrypting, traces of processing carried out by using the private key within the apparatus are outputted and when verifying, it is verified by using the stored traces whether or not encryption using a private key for trace preparation within the encrypting apparatus is performed except processing corresponding to the traces. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cryptographic processing method and device, a verification method, a device, and a proxy operation method, and more particularly to a cryptographic processing capable of subsequently verifying whether or not the cryptographic processing device is used outside the business use. The present invention relates to a method and an apparatus, a verification method and an apparatus, and an operation proxy method.

[0002]

2. Description of the Related Art In an information processing system (for example, a certificate authority) that uses a cryptographic process using a secret key, the secret key owner (who owns the secret key and is the service provider of the information processing system) For example, the certification company)
Operate the operation of the information processing system (for example, S
There are many cases where services are outsourced to an I business operator.

[0003] In order to prevent the operation agent from performing illegal operation,
The following techniques are used.

[0004]

An access right to an information system is set so that only an authorized person can operate it.

A secret key is generated and held in the tamper resistant device, and a cryptographic process is executed in the device to physically prevent leakage of the key.

Obtaining the logs of the computer that constitutes the information processing system and including the hash value of the previous log in the log, or adding a digital signature to the log, and auditing these logs ex post facto To do.

With the above technique, it is possible to verify that the proxy operation is properly performed only when the private key by the operation proxy is not used outside the intended purpose.

[0008] However, in many cases, the administration agent carries out the administrative work having the highest authority of the computer constituting the target information system. Used for
By falsifying the log in the computer of the above-mentioned information system, the private key can be used without being known to the private key owner.

Conventionally, such measures against fraud depend on the social trust of the operation agent and the contract obligation, and are not systematically resolved.

The present invention has been made in view of the above points, and a cryptographic processing method and apparatus, a verification method and an apparatus capable of early detection of fraud by any person having any authority relating to the operation of an information system. The purpose is to provide a method for operating operations.

[0011]

According to the present invention, a secret key for use in business is managed in a tamper resistant device, and an encryption process including a digital signature and encryption is executed using the secret key. In the cryptographic processing method, a trail that the processing using the secret key in the device is executed is output.

According to the present invention, information for specifying an output result of a process using a secret key in a device and continuity information indicating continuity of a process and a process executed in the device before the process are provided. The processing result of the included audit information using the trail creation private key managed in the device is output as a trail.

The cryptographic processing method of the present invention uses a digital signature as the processing using the private key for trail creation.

The cryptographic processing method of the present invention uses common key cryptographic processing as the processing using the private key for trail creation.

The cryptographic processing method of the present invention uses a hash operation as the processing using the private key for trail creation.

FIG. 1 is a diagram for explaining the principle of the present invention.

According to the present invention, in a tamper-proof device, a secret key for use in business is managed, and an encryption method including a digital signature and encryption is performed by using the secret key from a server system of an information processing system. The signature target electronic message is received (step 1), a business signature is created from the stored private key for business and the signature target electronic message (step 2), the process executed using the private key of the device and the process The continuity information indicating the continuity of the previously executed process is updated (step 3), and the trail creation private key and the business signature for creating the trail of the process executed by using the private key in the device are stored. A trail signature is created from the continuity information (step 4), and the trail signature, business signature, and continuity information are transmitted to the server system (step 5).

The present invention is a cryptographic processing device for managing a secret key for use in a business in a tamper resistant device and executing an encryption process including a digital signature and encryption using the secret key. , And has means for outputting a trail indicating that the processing using the secret key in the apparatus has been executed.

The cryptographic processing apparatus of the present invention shows the information for specifying the output result of the processing using the secret key in the apparatus and the continuity of the processing and the processing executed in the apparatus before the processing. There is provided means for outputting, as a trail, a processing result for the audit information including the continuity information using the trail creating private key managed in the apparatus.

The cryptographic processing apparatus of the present invention uses a digital signature as the processing using the private key for creating a trail.

The cryptographic processing apparatus of the present invention uses the common key cryptographic processing as the processing using the private key for trail creation.

The cryptographic processing device of the present invention uses a hash operation as a process using the private key for trail creation.

FIG. 2 is a block diagram showing the principle of the present invention.

The present invention is a cryptographic processing apparatus for managing a secret key for use in a business in a tamper resistant apparatus and executing an encryption process including a digital signature and encryption using the secret key. , Private key The private key for business possessed by the owner, the private key for creating a trail for creating a trail of processing executed using the private key in the device, and the private key in the device A storage unit 220 for storing the executed process and continuity information of the process executed before the process, a receiving unit 211 for receiving a signature target message from the server system of the information processing system, a business private key and a signature target. Encryption processing means 230 for creating a business signature from a message; trail information creating means 240 for updating the continuity information and creating a trail signature from the private key for creating a trail, a business signature, and the continuity information; Trail Signature, and a transmitting means 212 for transmitting the commercial signature and continuity information to the server system.

According to the present invention, in the verification method for verifying the trail information of the processing executed by using the private key for business in the device, the private key for business in the device is used by using the accumulated trail. It is verified whether or not the process is other than the one corresponding to the trail.

According to the present invention, in a verification method for verifying trail information of a process executed by using a business private key in a device, a business signature stored in a storage unit within a certain operation period. Then, the trail information obtained by operating the private key is input (step 6), and the signature of the trail information is verified using the verification key stored in the storage means (step 7).
The continuity of the business signatures stored in the storage means is verified (step 8), and if both the signature verification and the business signature continuity verification are valid, the process using the private key in the device is performed. The verification result is output as the trail information is correct (step 9).

The present invention is a verification device for verifying trail information of a process executed by using a business private key in the device, wherein the business private key in the device is verified by using the accumulated trail. It has means for verifying whether or not the processing used was other than the one corresponding to the trail.

The present invention is a verification device for verifying trail information of a process executed by using a private key for business in the device, and a storage means 320 for storing a signature for business and trail information and a verification key. An input means 311 for inputting the business-use signature accumulated in the storage means within a certain operation period and the trail information, and a signature verification means 330 for verifying the signature of the trail information using a verification key. , Continuity verification means 340 for verifying the continuity of business signatures stored in the storage means
If both the signature verifying means 330 and the continuity verifying means 340 are valid, the output means 3 for outputting the verification result assuming that the trail information of the process using the secret key in the device is proper.
12 and.

The present invention is an operation proxy method for acting on behalf of an owner of a private key, who owns the private key, to operate an information system that manages and encrypts the private key. The device generates a business private key and a trail private key, and the cryptographic processing device acquires the public key corresponding to the business private key and the public key corresponding to the trail private key to operate the information system. Request the operation agent, in the information system, obtain the business signature and the trail information, and send it to the cryptographic processing device, and the private key owner verification device receives the business signature and the trail information, Accumulate,
Using the trail information, it is verified whether or not the encryption processing using the private key for business use in the cryptographic processing device is other than the one corresponding to the trail.

As described above, in the present invention, the operation proxy outputs a trail of the past cryptographic processing execution using the secret key in the cryptographic processing device and the key operation implementation including the duplication of the secret key. By presenting this trail to the private key holder, the private key holder can verify with the verification device that the private key is not used for any purpose other than business processing. Therefore, a person who has any authority regarding the operation of the information system cannot tamper with the trail.

[0031]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 3 shows the configuration of a cryptographic processing device according to an embodiment of the present invention.

The cryptographic processing used for business in the cryptographic processing device described below is, as an example, a digital signature using a business private key, but a common key cryptographic processing, a hash object, or a combination of these. It can also be applied to processing.

The information processing system shown in this embodiment is
Server system 10 which is an ordinary computer system
0 and the cryptographic processing device 200.

The cryptographic processing apparatus 200 includes an input / output unit 210 for inputting / outputting information to / from the outside of the apparatus, a business private key 221 owned by a private key owner, a trail private key 222, and a business cryptographic processing. Storage unit 220 that stores continuity information 223
And a cryptographic processing unit 230 that performs business signature processing, a trail information creation unit 240 that creates trail information, and a control unit 250. Further, as a general configuration example, it has a key operation unit 260 having a function of generating a key and the like.

The server system 100 of this embodiment is
A business processing unit 110 that performs business processing other than cryptographic processing, a communication unit 120 that communicates with the outside of the system, a business signature storage unit 131 that stores business signatures, and a trail information storage unit 132 that stores trail information. It has a storage unit 130, a device control unit 140 that controls the cryptographic processing device 200, and a control unit 150.

In the present embodiment, the business private key and the trail private key are set separately, but they may be the same key.

The trail secret key may be a secret key of public key cryptography, a secret key of common key cryptography, an arbitrary random number used for hashing, a combination thereof, or similar cryptographic processing. . Various other examples are possible.

Next, the operation of the above configuration will be described.

FIG. 4 is a flowchart of the processing of the information processing system according to the embodiment of the present invention.

The communication unit 120 of the server system 100 receives a message from the network (step 10
1) The business processing unit 110 creates a signature target sentence by processing the received electronic message (step 102), and the control unit 150 transmits the signature target sentence to the cryptographic processing device 200 (step 103).

The input / output unit 210 of the cryptographic processing apparatus 200 receives the signature target text transmitted from the server system 100 (step 104), and the cryptographic processing unit 230 performs signature processing on the signature target text with the business private key. A business signature, which is the result of the execution, is created (step 105), and the continuity information is updated in the trail creating unit 240 (step 10)
6) The trail creating unit 240 creates a trail signature from the audit signature, which is the information including the business signature and the continuity information, using the trail private key (step 107), and the input / output unit 210 creates the business signature. , And sends trail information including a trail signature and audit information to the server system 100 (step 10).
8).

The communication section 120 of the server system 100 receives the output information of the cryptographic processing apparatus 200 (step 109), and the storage section 130 stores the output information.
It is saved (step 110) and the business signature is transmitted from the communication unit 120 (step 111).

As described above, the main business of the information processing system according to the present embodiment includes the business of adding the digital signature to the signature target sentence obtained by processing the received electronic message with the business private key and transmitting it. . For example, if the signature target sentence is considered as a public key certificate, this embodiment corresponds to a component of a general certification authority (CA) system. Further, if the signature target sentence is considered as receipt information, it corresponds to a component of a general electronic commerce system. As described above, the present embodiment is a model applicable to a wide range of information processing jobs.

On the other hand, the trail information does not appear in the input / output of the normal service of the information system. This is because of the information used between the private key holder and the operation agent.

The continuity information in the present embodiment is information indicating the continuity of the process using the private key for business in the cryptographic processing device 200 and the process performed in the device before the process. There can be many examples of continuity information, for example:
A fixed number of serial numbers can be applied each time the business signature process is performed. Alternatively, the previous business signature itself may be used.

The trail signature in the present embodiment corresponds to a digital signature in which the audit information is in plain text when the trail secret key is a secret key in the cryptographic processing using the trail creating secret key. If the secret key for the trail is the common key, the ciphertext with the audit information as plaintext is equivalent, and if the hash operation is used as the cryptographic process, the hash value including the secret key for the trail and the audit information is Equivalent to.

In the present embodiment, the trail information is generated each time the business encryption process is executed once, but it is also possible to output the single trail information by collecting the business encryption processes for a plurality of times. is there.

Next, a verification device for verifying the trail information will be described.

FIG. 5 is a block diagram of a verification device for verifying the trail information according to the embodiment of the present invention.

The verification apparatus 300 has an input / output unit 310 for inputting / outputting information to / from the outside, a verification key 321, a business signature storage unit 322 for storing a business signature, and trail information storage for storing trail information. The storage unit 320 includes a unit 323, a signature verification unit 330 that verifies the signature of the trail, a continuity verification unit 340 that verifies the continuity of the stored business signatures, and a control unit 350.

The verification key 321 is a public key corresponding to the trail creating secret key, and is equal to the trail secret key in the common key cryptographic process and the cryptographic process using the hash operation. In addition, when performing cryptographic processing using common key cryptographic processing and hash calculation, it is necessary to securely deliver the verification key to the verification device without being acquired by the operation agent, and this is realized. In order to do so, many examples using an IC card or the like can be considered.

Next, the operation of the verification device having the above configuration will be described.

FIG. 6 is a flowchart of a trail verification process using the verification device according to the embodiment of the present invention.

First, the input / output unit 310 inputs the business signature and the trail information accumulated within a certain operation period (step 201), and the signature verification unit 330 uses the verification key to sign the trail information. If it is verified (step 202) and the signature verification is valid (step 203, valid), the continuity verification unit 3
The continuity of the business signatures accumulated in 40 is verified (step 205), and if there is continuity (step 20).
6, Yes), it is determined that the verification result is appropriate (step 208), and the verification result is output from the input / output unit 310 (step 209). If the signature verification result is an error (step 203, err), the verification result is invalid (step 204), and "Illegal" is output from the input / output unit 310 as the verification result (step 209). As a result of verifying the continuity of the signature order, if there is no continuity (No in step 206), the verification result is invalid (step 207), and "invalid" is output from the input / output unit 310 as the verification result. (Step 209).

That is, the verification result is “appropriate” only when both the signature verification and the verification of the continuity of the signature order are valid.
Becomes

When the continuity information is a serial number, the verification processing in the continuity verification unit 340 may be performed by confirming that the numbers are continuous without jumping. When the continuity information is the previous signature processing, it is sufficient to recursively confirm that the signature included in each audit information is the previous signature. In addition to the above, in the case of many possible methods of implementing continuity information, verification suitable for them may be performed.

With the above-described trail verification method, it is possible to use the accumulated trails to verify whether or not the processing using the secret key in the cryptographic processing device 200 is other than the processing corresponding to the trails. That is, if a business signature other than the one input to the verification device is executed, an error should occur in the continuity verification. This result cannot be overridden without cryptographically breaking the trail signature or breaking the tamper resistance of the cryptographic processor.

[0058]

Embodiments of the present invention will be described below with reference to the drawings.

In this embodiment, an example of a method for acting as an information system operation is shown.

FIG. 7 is a business flow of the operation agency of the information system of the embodiment of the present invention.

In the cryptographic processing device of the present invention, in an information processing system (for example, a certificate authority) that manages a private key, the private key is owned by the private key, and the private key provided by the information processing system is the service entity. A case in which a person (for example, an authentication business operator) entrusts the operation of the information processing system to an operation agent (for example, an SI business operator) to operate the service is applicable.

First, the private key owner and the operation agent exchange a contract, and the private key owner uses the cryptographic processing apparatus 200 to generate a business private key and a private trail key (step 3).
01), the verification key is obtained by the device (step 30).
2) Request the operation agent to operate the information system (step 303).

The operation agent operates the information system for a certain period of time (step 304), acquires the business signature and the trail information accumulated in the information system during the same period (step 305), and possesses the secret key. (Step 306).

The private key holder receives the business signature and the trail information (step 307), verifies the trail information with the verification device 300 (step 308), and verifies that the private key is properly operated. If (step 309, Yes),
Continue to request proxy operation (Step 310, Ye)
s). On the contrary, when the use of the key that does not remain in the trail is found (step 309, No), the private key owner makes a complaint to the operation agent (step 311), and the operation agent takes responsibility for the liability based on the contract. Etc. (Step 31)
2).

It should be noted that although the present embodiment discusses only the verification of the use of the secret key according to the present invention, it goes without saying that
There is no point in verification unless auditing of the business itself by conventional technology is also performed.

Further, when the present invention is actually carried out, it is not a rational act to use an unauthorized private key, knowing that the operation agent is verified. That is, the present invention brings about an effect of suppressing illegal operation.

The components of the cryptographic processing device and the verification device shown in FIGS. 3 and 5 can be constructed as a program and installed in a computer used as the cryptographic processing device and the verification device.

Further, a hard disk device connected to a computer used as a cryptographic processing device and a verification device for the constructed program, a flexible disk, C
It is also possible to store it in a portable storage medium such as a D-ROM and install it when carrying out the present invention.

The present invention is not limited to the above-described embodiments and examples, but within the scope of the claims.
Various modifications and applications are possible.

[0070]

As described above, according to the present invention, the operation agent performs the past cryptographic processing using the secret key in the cryptographic processing device and the key operation including the duplication of the secret key. The trail is output, and this trail is presented to the private key holder, and the private key holder can verify that the private key is not used for any purpose other than business processing by the verification device.

A person who is involved in the operation of the information system or who has any authority cannot tamper with the trail.

As a result, it is possible to technically avoid the risk of the private key owner and the operation agent associated with the possibility that the private key may be illegally used.

[Brief description of drawings]

FIG. 1 is a diagram for explaining the principle of the present invention.

FIG. 2 is a principle configuration diagram of the present invention.

FIG. 3 is a configuration diagram of a cryptographic processing device according to an embodiment of the present invention.

FIG. 4 is a flowchart of processing of an information processing system according to the embodiment of the present invention.

FIG. 5 is a configuration diagram of a verification device for verifying the trail information according to the embodiment of the present invention.

FIG. 6 is a flowchart of a trail verification process using the trail verification device according to the embodiment of the present invention.

FIG. 7 is a business flow of an operation agency of an information system according to an embodiment of the present invention.

[Explanation of symbols]

100 server system 110 Business Processing Department 120 Communication unit 130 storage 131 Business signature storage 132 Trail information storage unit 140 Device control unit 150 control unit 200 Encryption processing device 210 Input / output section 211 Receiving means 212 Transmission means 220 storage means, storage unit 221 Private key for business 222 Private key for trail 223 Continuity information 230 Cryptographic processing means, cryptographic processing section 240 Trail information creating means, trail information creating unit 250 control unit 260 Key Operations Department 300 Verification device 310 Input / output unit 311 input means 312 Output means 320 storage means, storage unit 330 signature verification means, signature verification unit 340 Continuity verification means, continuity verification unit

Claims (17)

[Claims] 1. A cryptographic processing method for managing a private key for use in a business in a tamper resistant device, and performing an encryption process including a digital signature and encryption using the private key, comprising: 2. A cryptographic processing method, comprising outputting a trail of execution of processing using the secret key. 2. The information includes information specifying an output result of a process using a secret key in the device, and continuity information indicating continuity of the process and a process performed in the device before the process. 2. The encryption processing method according to claim 1, wherein the processing result of the audit information using the private key for business managed in the apparatus is output as a trail. 3. The cryptographic processing method according to claim 2, wherein a digital signature is used as the processing using the private key for creating a trail. 4. A cryptographic processing method according to claim 2, wherein common key cryptographic processing is used as the processing using the private key for trail creation. 5. The cryptographic processing method according to claim 2, wherein a hash operation is used as the processing using the private key for trail creation. 6. An encryption method for managing a private key for use in a business in a tamper resistant apparatus, and using the private key to include a digital signature and encryption, a server system of an information processing system signs a signature target. A process of receiving an electronic message, creating a business signature from the stored private key for trail creation and the electronic message to be signed, and executing the process using the private key in the device and the process performed before the process. The continuity information indicating the continuity of the information is updated, and a trail signature is created from the private key for trail creation for creating a trail of processing executed using the private key in the device, the business signature, and the continuity information. A cryptographic processing method which is created, and which transmits the trail signature, the business signature, and the continuity information to the server system. 7. A cryptographic processing device that manages a private key for use in a business in a tamper resistant device and executes an encryption process including a digital signature and encryption using the private key, the device comprising: A cryptographic processing device comprising: means for outputting a trail indicating that a process using the secret key is executed. 8. The information includes information specifying an output result of a process using a secret key in the device, and continuity information indicating continuity of the process and a process performed in the device before the process. 8. The cryptographic processing apparatus according to claim 7, further comprising means for outputting, as a trail, a processing result of the audit information, which processing is performed by using the trail creation private key managed in the apparatus. 9. The cryptographic processing device according to claim 7, wherein a digital signature is used as the process using the private key for creating the trail. 10. The cryptographic processing apparatus according to claim 7, wherein a common key cryptographic process is used as the process using the private key for trail creation. 11. The cryptographic processing device according to claim 7, wherein a hash operation is used as the process using the private key for trail creation. 12. A cryptographic processing device that manages a private key for use in a business in a tamper resistant device, and executes an encryption process including a digital signature and encryption using the private key, the secret processing device comprising: A private key for business use, which the key holder owns, a private key for creating a trail for creating a trail of the process executed by using the private key in the device, and a process executed by using the private key of the device. And storage means for storing continuity information indicating continuity of the processing performed before the processing, receiving means for receiving a signature target electronic message from the server system of the information processing system, the business secret key and the signature Cryptographic processing means for creating a business signature from the target message, updating the continuity information stored in the storage means, and using the private key for creating the trail, the business signature, and the continuity information for the trail. Create signature And trail information creation unit that, signing the trail, encryption processing apparatus characterized by a transmission means for transmitting the signature and the continuity information for the business to the server system. 13. A verification method for verifying trail information of a process executed by using a business private key in an apparatus, wherein the business private key in the apparatus is used by using an accumulated trail. A verification method characterized by verifying whether or not the processing is other than that corresponding to the trail. 14. A verification method for verifying trail information of a process executed by using a business private key in a device, wherein a business signature stored in a storage means within a certain operation period, and Input the trail information of the operation implementation of the business private key, verify the signature of the trail information by using the verification key stored in the storage unit, and store the business signature stored in the storage unit. If the verification of the business signature and the verification of the continuity of the business signature are both valid, the verification result that the trail information of the process using the private key in the device is correct is verified. A verification method characterized by outputting. 15. A verification device for verifying trail information of execution of a process using a business private key in the device, wherein the business private key stored in the device is used. A verification device comprising means for verifying whether or not the encryption processing that was performed was other than that corresponding to the trail. 16. A verification device for verifying trail information of a process executed by using a business private key in the device, comprising: a business signature, storage means for storing the trail information and the verification key, A signature verification unit for verifying the signature of the trail information by using the business signature stored in the storage unit within a certain operation period, the input unit for inputting the trail information, and the verification key. A continuity verifying means for verifying continuity of the business-use signatures stored in the storage means, the signature verifying means, and the continuity verifying means are valid, the business in the apparatus A verification device, comprising: output means for outputting a verification result that the trail information of the processing using the private key for use is proper. 17. An operation proxy method for acting on behalf of an owner of a private key, who owns the private key, to operate an information system for managing and encrypting the private key, wherein the private key owner's cryptographic processing is performed. In the device, a trail private key and a business private key are generated, and in the cryptographic processing device, a public key corresponding to the business private key and a public key corresponding to the trail private key are acquired, and the information Request the operation of the system to the operation agent, in the information system, to obtain the trail information that the operation signature and the private key is operated, and send to the verification device, in the verification device of the private key owner, Receiving and accumulating the business signature and the trail information, and using the trail information, the encryption processing using the business private key in the cryptographic processing device is not the one corresponding to the trail. Whether there was Proxy operation method which is characterized in that verification.