JP4710232B2 - Electronic data storage system that stores electronic data while guaranteeing the evidence - Google Patents

Description

The present invention relates to an electronic data storage device that stores electronic data such as an electronic file, and more particularly, provides long-term evidence that electronic data stored in such an electronic data storage device has not been tampered with. It relates to the technology to be guaranteed .

According to the present invention, when generating a signature for certain data, a MAC (Message Authentication Code) is also generated, and if it is suspected that the signature has been forged, the MAC is verified to confirm the hardware that generated the signature. And “determining the presence or absence of forgery” (Non-Patent Document 1). Conventionally, a digital signature with a MAC is a technique that shows evidence that electronic data such as an electronic file has not been tampered with.
FIG. 14 is a diagram showing a configuration of a conventional electronic data storage system. The system shown in FIG. 14 includes an electronic data storage server 910 connected to a network such as the Internet, and a number of client devices 920 connected to the same network. An external device 930 is connected to each client 920. The external device 930 has the authentication code private key K in an area where writing is not possible except during manufacture, and has the signature private key sk in a writable area. The external device 930 has a function of generating an authentication code and an electronic signature.

The client 920 gives a PIN (personal identification number) and electronic data X to the external device 930 and receives X, its electronic signature, and an authentication code from the external device 930. The client 920 can exchange data with the server 910 via a network such as the Internet. The client 920 passes X received from the external device 930, its electronic signature, and an authentication code to the server 910.

The server 910 has a data storage unit 980. The server 910 verifies the electronic signature of X received from the client 920, its electronic signature, and the authentication code, and stores data in the data storage unit 980 if normal. If there is a suspicion of forgery of the electronic signature, the mediator takes out the data X and the authentication code stored in the data storage unit, gives the PIN and electronic data X from the client 920 to the external device 930, By receiving the data X and its electronic signature and authentication code from the external device 930, the obtained authentication code is compared with the authentication code stored in the data storage unit 980. If they match, the electronic signature is forged. Judge that there is no.
Masashi Une, “Problems and Countermeasures Regarding Leakage of Private Key for Digital Signature Generation”, Bank of Japan Financial Research Institute, Discussion Paper No.2002-J-32 (2002)

  In the conventional system, an IC card is assumed as an external device, and a PC (personal computer) is assumed as a client. Since an IC card as an external device performs both processing of an electronic signature and an authentication code, processing time in seconds is required. Therefore, when it is necessary for a client to process a large amount of electronic data at high speed, the processing speed becomes an obstacle. In order to solve this problem, it is necessary to prepare a large number of personal computers and IC cards and perform parallel processing. Since each PC needs an IC card, there is a problem in terms of cost and operation in that an IC card must be prepared for all the subjects. In addition, since the electronic data is stored on the server 910 side and the processing of the electronic signature and the authentication code is performed on the PC side, the risk is distributed because of the distributed processing, and there is a high probability of exposure.

  Therefore, the present invention enables processing of electronic signatures and authentication codes on the server side at high speed and safely even in an environment in which a plurality of clients that process high-speed and large amounts of electronic data are connected or in an environment in which a large number of clients are connected. It is to provide a system that makes it possible.

The present invention has been made to solve the above problems, and the invention according to claim 1 is an electronic data storage system that guarantees the evidence of electronic data with an authentication code and an electronic signature. An electronic data storage system according to the present invention includes at least one server that can exchange electronic data with an external client and is electrically and mechanically coupled to an external device, a ROM area, a RAM area, and a CPU. And an external device connected to the server via an interface, and read-only storage means in which a secret key is burned into a storage area that cannot be rewritten by the manufacturer at the time of manufacture and access is restricted. External device, comprising software means for generating a temporary private key based on the secret key copied from a read-only memory means (algorithm) in the ROM region, the CPU based on the previous SL software means further has caused the random number generating only a temporary secret key number of the last of the one o'clock secret key generated is stored in the RAM area, and encapsulates at least part of the program that generates the authentication code from the one o'clock secret key and a given electronic data The ROM area is prepared as an object. Server, software means, and means for reading the object, and the temporary private key, the read software means, and authentication code generation object said object, and a temporary by using the secret key to generate an authentication code electronic data, electronic An electronic signature generation unit that generates an electronic signature by encoding data with a secret key , and a storage unit that stores the electronic data , the generated authentication code, and the generated electronic book name .

The read-only storage means is preferably stored by a third party who has no interest in both the server administrator and the client.
The server may further include a verification object that performs verification of an authentication code of electronic data stored in the storage unit using the authentication code generation object.

The server may include a policy table including policy records that define access restrictions, and may include means for restricting access to objects based on the policy tables.
The authentication code generation object discharges the log each time it is activated, and the server preferably includes means for storing the log in a predetermined storage area.

Any log server taken in time zone when receiving a predetermined command with the specified time zone, it is preferable to further comprising means for erasing the log any policy records and conditions policy table matches.

Any log server taken in time zone, with respect to the remaining logs without being erased, visual alarm, it is preferable to further comprising means for outputting an audible alarm, or both alarms.

  According to one embodiment of the present invention, the electronic data storage system includes a plurality of servers and a secondary storage device shared by the plurality of servers, and the secondary storage device stores electronic data of all servers. By having a data storage area, each of the plurality of servers has no storage means.

According to another embodiment of the present invention, the server includes a second external device, stores a second secret key different from the secret key of the first external device in the RAM area, and the authentication code generation object includes: software means read from the first external device, the object, and the temporary addition to the secret key, a second software means read out from the second external storage device, the second object, and the second temporary private key using generates an authentication code of electronic data.

  According to another embodiment of the present invention, the server includes a dividing unit that divides the electronic data into a plurality of divided data before generating the authentication code of the electronic data, and the authentication code generating object is 1 for each divided data. Generate authentication codes one by one.

  According to still another embodiment of the present invention, the dividing unit divides the electronic data into a plurality of variable length divided data, and the storage unit stores the authentication code and the length of the variable length divided data for each variable length divided data. Means for storing with information representing

By generating an authentication code and an electronic signature on the server side managing the electronic data, a large amount of data can be digitally signed with a MAC at high speed.
After mutual authentication of electronic data between the client and the electronic data storage server, the data is encrypted and transmitted, and at least the important parts of the authentication code generation process and signature generation process on the data storage server side are stored in an external device and read out By performing the authentication code generation object in a concentrated manner, high-speed and large-volume data processing can be performed by the digital signature scheme with MAC.

  In addition, since at least a part of the authentication code generation algorithm and the authentication code private key are written to an area that cannot be written thereafter at the time of manufacturing, they cannot be tampered with, and an external code that generates an authentication code temporary private key from the authentication code private key Since the device can be separated from the server and stored in a safe place, it can be protected from fraud such as theft, falsification, and destruction of the server and external devices.

The authentication code temporary secret key of the external device is temporarily generated by a random number, and the previous temporary secret key is deleted, so that the security of the authentication code secret key is maintained.
The external device of the authentication code private key and the authentication code generation algorithm is controlled by separate mutual authentication and PIN, the ROM can physically prevent theft and detect theft, and the server's authentication code generation process It is protected by a temporary secret key using random numbers and access right processing.

  In addition, the algorithm of the authentication code generation processing object of the server is adopted that can be processed at high speed. Further, the authentication code generation processing object of the server is protected by encapsulating unauthorized access by access control, and abnormal access can be detected by access restriction log filter processing or the like. Furthermore, unauthorized access due to spoofing of administrator privileges can be detected including auditing by log processing.

In addition, tampering with an electronic signature can be verified by an arbitrator using an authentication code verification process.
Therefore, it is possible to process the electronic signature and the authentication code at high speed and safely even in an environment in which a plurality of clients that process high-speed and large amount of electronic data, which is the object of the present invention, are connected.

Hereinafter, the present invention will be described in detail with reference to embodiments of the present invention and the accompanying drawings. In addition, when showing the same element in several drawing, the same referential mark is attached | subjected.
[First Embodiment]
FIG. 1 is a schematic block diagram showing the configuration of an electronic data storage system according to the first embodiment of the present invention. In FIG. 1, an electronic data storage system 1 according to the present invention includes an electronic data storage server 10 connected to a network such as the Internet, an input / output device 20 for an operator of the server 10 to operate the server 10, and an electrical connection to the server 10. An external device 30 that is connected and fixed mechanically and mechanically; and includes a plurality or a plurality of clients 920 that can communicate with the server 10 via a network. The external device 30 is securely fixed to the server 10 by mechanical coupling means 32 such as a wire and a lock 34. The input / output device 20 includes a display device, a keyboard, a pointing device, and the like. The electronic data storage server 10 is operated by an administrator who belongs to the organization that operates the server 10 and manages the server 10, and preferably audits the operation of the server 10 that does not belong to the organization that operates the server 10. It is preferable to limit the auditor and any of the above organizations or the mediator who has no interest in the user of the client 920.

The system 1 in FIG. 1 can be a document long-term storage originality assurance system in which the server 10 is an originality assurance server and the client is a document management server. Further, the system 1 in FIG. 1 can be a long-term data evidence guarantee system for electronic application data, with the server 10 as the originality guarantee server and the client 920 as the electronic application server. Furthermore, the system 1 of FIG. 1 can be a data evidence guarantee system that guarantees traceability data over a long period of time by using the server 10 as a data storage server and the client as a data collection server.

  The external device 30 includes a CPU (central processing unit) 60, a RAM (random access memory) 62, a ROM (read only memory) 64, and an interface (IF) 66 for exchanging data with the server 10. For example, an IC card or a USB key can be used as the external device 30. Here, description will be made assuming that an IC card is used. In addition, it is assumed that the manufacturer stores a hash function calculation program (represented by h) 70 for generating an authentication code and an authentication code generation object (represented by f) 72 in advance in the ROM 64 of the IC card 30. This format is stored in, for example, a Java (registered trademark) object intermediate file format.

  The ROM 64 does not need to store the entire program necessary for generating the authentication code, but records only an important part that is inconvenient if leaked to the outside as an object 72, and the remaining part is It may be stored as an object encapsulated separately on the server 10 side.

The ROM 40, is recorded secret key K0 for the authentication code generated at the manufacturer, by connecting to the external device 30 i.e. IC card, and to be able to copy the authorization code secret key K0 in the IC card 30 .

The external device 30 in m times the random number generated, performs m times hash computation of the authentication code secret key ^{K0 (Km = h m (K0} ), h hash function), the rewritable area hash value Km and m results Save and erase the authentication code private key K0. The external device, that is, the IC card 30 generates a random number p times every time the temporary secret key is accessed from the outside, and performs the hash calculation of the authentication code secret key Km p times the numerical value of the random number. The value (Kp = h ^p (Km)) is stored in the writable area 62, and the authentication code temporary secret key Km is deleted. At this time, with regard to the number of random numbers generated by the external device 30, if the value becomes too large, the performance may be affected. In such a case, an upper limit may be provided for the number of random numbers generated .

On the other hand, the electronic data storage server 10 is similar to a normal server, the CPU 11, ROM 12, RAM 13, communication interface 14 for communicating with the client 920 via the network, interface 16 to the input / output device 20, external devices, An external device interface 15 for connecting an IC card and a mass storage device 17 such as a hard disk are provided. The hard disk 17 stores the following programs and data. That is,
A data storage program 90 for storing electronic data requested to be stored by the client 920
A stored data storage unit 80 for storing electronic data
A data reading program 92 for sending electronic data to the requesting client 920 when there is a retrieval request from the client 920 for the electronic data stored in the stored data storage unit 80
An authentication code generation object 75 encapsulating the remaining program when only a part of the authentication code generation program is recorded in the ROM 64 of the external device 30
An authentication code verification object 96 that verifies the authentication code of the stored data with the normal authentication code when there is a suspicion of forgery of the electronic signature in some stored data
Access restriction program 94 that restricts access to programs with restricted access
Policy table 82 that is referred to during access restriction processing
A log table 84 that stores a log recorded each time various objects are activated.
-Log filter 98 for checking abnormal logs due to unauthorized access
Note that the communication between the server 10 and the external device 30 and the communication between the server 10 and the client 920 are both performed by mutual authentication (ECOM IC card usage guideline 1.0 version (1008 3 1))) to prevent unauthorized use.

  Further, the server 10 gives a PIN (personal identification number) to the external device 30 for authentication. It is preferable that the external device 30 has a function of improving safety, such as stopping the processing when erroneous PINs are continuously received. The server 10 and the client 920 perform mutual authentication and ensure safety by encrypting and sending data.

The operation and operation of the electronic data storage system 1 having the above configuration will be described.
FIG. 5 is a flowchart showing the procedure up to the start of operation according to the principle of the present invention. In FIG. 5, the manufacturer of the ROM 40 first generates an authentication code private key K0 in step 100, and in step 102 burns the authentication code private key K0 into the ROM 40. The ROM 40 obtained upon installation of the server 10 is preferably stored in a safe place by an auditor or a mediator. Next, we have you to step 104, the manufacturer, mediator or auditors copy the authentication code secret key K0 in ROM40 to RAM62 of the external device 30.

In step 106, the manufacturer, mediator, or auditor generates a random number m times in the external device 30, and uses the random number generation number m and the hash function calculation program stored in the ROM 64 to authenticate the authentication code private key. K0 is calculated m times, and in step 108, the IC card 30 is connected to the server 10 and fixed. In this case, it is desirable to fix it with a cable and lock it. As a result, the administrator can operate the server 10 (step 110).

In normal operation, a data storage process 90 for storing electronic data from the client in the server 10 in response to a client request, and data reading to send the data stored in the server 10 to the client in response to a client request are performed. Is called.
<Data storage>
When data to be stored in the data storage server 10 is generated on the client 920 side, the client 920 encrypts the data in a computer-readable format as electronic data, and stores it via a network together with a storage or registration request. The data is sent to the data storage server 10. In this case, first, the operator of the client 920 sends his / her PIN (personal identification number) to the data storage server 10, and the data storage server 10 has a PIN list (not shown) of personnel permitted to use the client 920. ), The client 920 is allowed to perform subsequent operations only when the received PIN exists. Prior to electronic data communication, the mutual authentication shown in FIG. 6 is performed between the client 920 and the data storage server 10 as described above.

  When the data storage server 10 receives a storage or registration request for electronic data (X) from the client 920, the data storage server 10 performs an authentication code generation process described later. A program for performing the authentication code generation processing is an object having both an access restriction function and a log data discharge function that can be accessed only by a specific user and an object by, for example, a Java (registered trademark) Security Manager function. It is an encapsulated program. Further, all of the authentication code generation object may be burned as an authentication code generation object (OBJ) 72 in the ROM 64 of the external device 30 when the external device 30 is manufactured, or only an important part of the authentication code generation object is manufactured in the ROM 64. Occasionally, an AC generation object (OBJ) 72 may be burned, and the remaining part may be stored in the auxiliary storage of the data storage server 10 as an AC generation OBJ75. Of course, the AC generation OBJ75 on the auxiliary storage of the data archiving server 10 is also protected so that only the administrator authority can access it. By doing so, it is possible to prevent the object to be subjected to the authentication code generation process from being stolen.

  The data storage server 10 performs an authentication code generation process, generates an authentication code, and then performs an electronic signature on the electronic data X, and stores the electronic data X, the authentication code, and the electronic signature as a set in the storage data recording unit 80. To do.

  FIG. 7 is a flowchart illustrating an operation in which the CPU 11 generates an authentication code under the control of the authentication code generation object 72 (or a combination of 72 and 75) according to an embodiment of the present invention. In FIG. 7, first, in step 120, the data storage program 90 reads the hash function h value calculation object 70 and the authentication code generation f object 72 from the ROM 64 of the external device 30 into the RAM 13. When the ROM 64 is accessed, the mutual authentication shown in FIG. 6 and access control by PIN are performed. The authentication code generation f object 72 is stored in the ROM 64 in, for example, an intermediate file format of a Java (registered trademark) object, and is read by the data storage program 90 and directly written in the main memory 13 by dynamic addition of classes. be able to.

Next, in step 122, the program 90 reads the authentication code generation temporary secret keys Km and m from the RAM 62 of the external device 30. When accessing the rewritable area 62 of the external device 30, mutual authentication and access control by PIN shown in FIG. 6 are performed. In step 124, the received electronic data file is fetched, a random number is generated n times , an authentication code generation temporary secret key Km is subjected to hash operation hn (Km) (= hm + n (K0)), and Km is hashed n times. An operation value (temporarily expressed as Kmn) is obtained and used as a secret key. Km is erased after Kmn is generated.

As the hash calculation object, an object different from the object h of the external device 30 may be provided on the data storage server 10 side. By doing so, the system can be easily mounted, the load on the data storage server 10 is reduced, and the performance is improved. In addition, an upper limit may be set for the number of random numbers generated .

  Next, in step 126, the program 90 passes the control to the read authentication code generation f object, and obtains the message authentication code calculation value MAC (X) = f (X, Kmn). After generating the message authentication code, the calculation of Kmn ′ = h (Kmn) is performed, and the secret key is protected by deleting Kmn. A known algorithm such as HMAC or UMAC can be used to generate the message authentication code. In step 128, the electronic data X and the acquired authentication code are passed to a signature generation object (not shown). This authentication code includes a message authentication code calculation value MAC (X) and the number of hashes m and n. Furthermore, when the data storage system has a cluster structure with a plurality of data storage servers 10 as shown in FIG. 12, the authentication code includes an identification code or number (ID) of the authentication code generation f object 72, and an authentication code generation. An identification code or number (ID) of the secret key Kmn is further included. It should be noted that the hash times m and n can be encrypted and stored in order to prevent theft or leakage of secret information.

  In step 130, the data storage program 90 determines whether or not a processing end instruction has been received from the administrator. The above steps 124 to 128 are repeated until reception. When the process end instruction is received from the administrator, in step 132, the read authentication code generation f object 72 and authentication code generation temporary secret key Kmn ′ are deleted. Finally, the data storage program 90 includes the electronic data (X) file, the above-described authentication code (that is, the message authentication code MAC (X), the hash times m and n, the ID of the authentication code generation f object 72, and the authentication code generation. The secret key Kmn ID set) and the electronic signature generated in step 128 are stored in the storage data recording unit 80 as shown in FIG.

  In FIG. 2, the file is an electronic data file to be stored sent from the client 920. The authentication code is the authentication code described above. The electronic signature is an electronic signature generated for the electronic data X using a secret key.

The electronic signature method and the private key may be changed at any time in order to prevent compromise and ensure safety.
<Read data>
When the client 920 needs electronic data stored in the storage data recording unit 80, the data storage server 10 sends an electronic data read request via the network together with information (electronic data identification information) that can identify the necessary electronic data. Send to. Of course, in this case as well, the client 920 is subject to the mutual authentication and PIN access restriction of FIG.

When the data storage server 10 receives the electronic data read request and the electronic data identification information, the data read program 92 takes out the record of the electronic data specified by the electronic data identification information from the storage data recording unit 80 and extracts the extracted electronic data. Whether or not the data has been tampered with is verified by decrypting the electronic signature with the signature public key and verifying the match with the data digest. If they match and the signature verification is successful, the data reading program 92 sends the read electronic data to the requesting client 920 via the network. If they do not match and the signature verification fails, the data reading program 92 notifies the client 920 to that effect via the network and also issues a visual alarm, an audible alarm, or both, to the administrator. Inform.
<Authentication code verification>
If any one of the administrator, the operator of the client 920, or the user who received the service through the client 920 determines that the electronic signature of some stored data (X) is suspected of being counterfeited, the arbitrator is suspected. It is possible to request verification of verification code of stored data X having a certain number. FIG. 8 is a flowchart showing the authentication code verification procedure according to the first embodiment of the present invention. In FIG. 8, when the authentication code is collated, first, in step 140, the administrator authenticates the electronic data X designated by the mediator (that is, the message authentication code MAC (X), the number of hashes m and n, the authentication number). Code generation object ID and authentication code generation private key ID) are passed to the mediator.

  Next, in step 142, the mediator copies the stored authentication code generation secret key K 0 of the ROM 40 to the RAM 62 of the external device 30. At this time, when the evidence-proof electronic data storage system has a cluster structure with a plurality of data storage servers 10 as shown in FIG. 12, the authentication code generation object ID and the authentication code generation private key ID match the electronic data X. It is necessary to copy to the RAM 62 of the external device 30. In step 144, the mediator activates the authentication code verification object 96 in the data storage server 10 of the external device 30 that has copied the secret key K0.

  In response to this, the authentication code verification object 96 first causes the auditor to input a PIN in step 146 and determines in step 148 whether the input PIN is permitted. By doing so, it is possible to prevent leakage of the PIN. Only when the PIN is permitted in step 148, the process proceeds to the next step 120. In steps 120 to 126, an authentication code is generated as described in FIG. Next, in step 148, the authentication code verification object 96 determines whether or not the verification code passed from the mediator in step 140 matches the verification code calculated in step 126. If they match, it is determined in step 150 that the electronic signature of the electronic data X is authentic, and if they do not match in step 148, it is determined in step 152 that the electronic signature of the electronic data X is counterfeit.

In this way, the authenticity of the electronic signature can be confirmed.
<Access right processing>
FIG. 3 is a diagram illustrating a configuration example and data example of the policy table recorded in the policy table recording unit 82 of FIG. As shown in FIG. 3, the policy table 82 of FIG. 1 is composed of a target policy and an access policy / filter policy. As shown in the configuration example 820, the target policy includes a target object, a permitted access ID, a permitted access source, and a permitted access destination. It is provided to identify the target of the access process and the items to be the target of the log process and log filter process described later. The target object stores the object name that is the target of the access policy and filter policy. The permitted access ID stores the ID of the person who permits the access that is the target of the access policy and the filter policy. The permitted access source stores the object name of the access source that is the target of the access policy and the filter policy. The permitted access destination stores the object name of the access destination that is the target of the access policy and the filter policy. An example of data of the target policy is indicated by element number 822.

  As shown in the configuration example 830, the access policy / filter policy includes a time zone, a target object name, a permitted access ID, a permitted access source, and a permitted access destination. As a set of these data, the time zone used in the access right processing and log filter processing described later stores the time zone in which access is permitted in the access right processing. The target object name stores the object name that is the target of the access policy and the filter policy. The permitted access ID stores the ID of the person who permits the access that is the target of the access policy and the filter policy. The permitted access source stores the object name of the access source that is the target of the access policy and the filter policy. The permitted access destination stores the object name of the access destination that is the target of the access policy and the filter policy.

  Element numbers 832 to 838 are data examples of the access policy / filter policy. For example, the access policy and filter policy 832 stipulates that the dump command activated from the command screen has an access right only by the administrator but is prohibited from accessing all day. The access policy / filter policy 834 indicates that the authentication code generation object activated from the data input process has an access right for the auditor within the range of the fixed time on weekdays. The access policy / filter policy 838 indicates that the log data processing started from the command screen as described later has an access right for the auditor within the range of the regular time on weekdays. In the access policy / filter policy 836, as described above, the authentication code generation object 72 (or a combination of 72 and 75) activated by the authentication code verification object has an access right to the arbitrator within a fixed range on weekdays. It is shown that.

The policy table 82 is protected so that only an auditor can access it. Access restriction or right processing is the one in which the access policy / filter policy is read from the policy table 82, and the object specified by the target object of the target policy matches all the one-time zone, the permitted access ID, the permitted access source, and the permitted access destination. Only the process of granting access authority. For this, for example, the Security Manager function of Java (registered trademark) can be used.
<Log management>
According to the present invention, the object specified by the target object of the target policy 822 has a function of discharging a log each time it is executed, and the discharged log is stored in the log table 84 in the format shown in FIG. Is done. In FIG. 4, each log includes a time when the log is generated, a log collection object, an accessor ID, an access source, and an access destination. The log collection object is the name of the access target object that collected the log, the access source is the access source object name, and the access destination is the access target object name.

  The log stored in this way is protected so that only a log access authority such as an auditor other than the administrator can refer to or delete the log. The auditor audits the work of the administrator of the data storage server 10 by referring to the audit of the log data stored in the log table 84 or the warning data of the log filter processing.

  When the auditor wants to audit or check the log data stored in the log table 84, the log filter program or the object 98 can be activated by designating a desired time zone within a regular time on weekdays. FIG. 9 is a flowchart illustrating a log filter operation performed by the log filter object according to the present invention. First, in step 170, the log record of the time zone specified by the parameter by the auditor is read from the log storage table 84, and the record of the target policy is read from the target policy 822 in step 172. Next, in step 174, an item described in the record of the target policy is extracted from the log record, and if the item exists in the log record, the log record is extracted. In step 176, the access policy / filter policy 832-838 is read. In step 178, the records extracted in step 174 that have conditions that match any of the read access and filter policies 832 to 838 are deleted. In step 180, the remaining records are output as warnings to the administrator and the auditor as abnormal records. This makes it possible to find unauthorized access outside the authority.

According to the present invention, since the policies 832 to 838 are used not only for access restriction but also for log filtering, safety can be improved efficiently.
[Second Embodiment]
In the first embodiment, the authentication code is generated for the entire electronic data X from the client 920. However, the electronic data X may be divided into a plurality of pieces and the authentication code may be generated for each divided data. FIG. 10 is a flowchart showing a procedure for dividing the electronic data X and generating an authentication code for each divided data. In step 200 of FIG. 10, the hash function h value calculation object 70 and the authentication code generation f object 72 are read into the RAM 13 from the ROM 64 of the external device 30. Next, in step 202, authentication code generation temporary secret keys Km and m are read from the RAM 62 of the external device 30. In step 204, the electronic data X is read, the electronic data X is divided into p, and X1, X2,. . . , Xp. Next, in step 206, p random numbers n1, n2,. . . , Np are generated, ni times hash operation hni (Km) (= hm + ni (K0)) of each divided data Xi (i = 1, 2,..., P) is performed, and km ni times hash operation value ( Temporarily, this is expressed as Kmni, and this is used as a secret key. In step 208, a message authentication code calculation value MAC (Xi) = f (Xi, Kmni) is obtained for each divided data Xi (i = 1, 2,..., P). In Step 210, Steps 206 and 208 are performed for all i (up to i = p), and then Step 212 is performed. In step 212, the electronic data X and the acquired authentication code are passed to a signature generation object (not shown). This authentication code includes a message authentication code calculation value MAC (Xi) and the number of hashes m, ni (i = 1, 2,..., P). Further, when the data storage system has a cluster structure with a plurality of data storage servers 10 as shown in FIG. 12, the authentication code includes an identification code or number (ID) of the authentication code generation f object 72 and an authentication code generation. Further included is an identification code or number (IDi (i = 1, 2,..., P)) of the secret key Kmni.

  Further, in step 214, it is determined whether or not a processing end instruction has been received from the administrator. Steps 204 to 212 are repeated until reception. When the process end instruction is received from the administrator, in step 216, the read authentication code generation f object 72 and authentication code generation temporary secret key Km are deleted. Finally, the data storage program 90 includes an electronic data (X) file, the authentication codes MAC1, MAC2,. . . , MACp and signature are stored in the storage data storage unit 80 as shown in FIG.

Note that the division in step 204 may be equal division or variable length division. However, when variable length division is performed in step 204, it is necessary to add a data length to each authentication code MAC (Xi) and record it in the storage data recording unit.
[Third Embodiment]
FIG. 12 is a schematic block diagram showing a configuration example of the evidence-proof type electronic data storage system 2 including a plurality of electronic data storage servers according to the third embodiment of the present invention. In FIG. 12, the data storage server 10 is the same except that the data storage server 10 is replaced with three data storage servers 10a and the disk server 8 commonly connected to the three data storage servers 10a. Instead of including the storage data unit 80, the log table 84, and the policy table 82, the disk server 8 does not have the respective tables 80 to 84. The identification number of the authentication code private key and the identification code generation object may be set the same among the servers constituting the cluster or may be set individually. When individually set, the verification code verification in FIG. 8 by the mediator is performed by a server connecting the external device 30 that has generated the authentication code and the ROM 64.
[Fourth Embodiment]
In the above embodiment, one external device is connected to one server, but a plurality of external devices can be connected to one server. In this case, the data archiving server 10b acquires the authentication code secret key and the number of occurrences of the random number from both the external devices 30 and 30a, and the authentication code MAC (X) = f ′ (f (X, Kn), K ′. n ′). FIG. 13 shows an example in which two external devices are attached to the data storage server 10b. It is also possible to attach three or more external devices to one data storage server 10b. By distributing the secret to a plurality of external devices, the security of the authentication code can be enhanced.

Embodiments 2 to 4 described above can be combined with any two or three.
The above are merely examples for explaining the present invention. Accordingly, it is easy for those skilled in the art to make various changes, modifications, or additions to the above-described embodiments in accordance with the technical idea or principle of the present invention.

  For example, in the above example, the data storage server is connected to a plurality of clients via the network, but it is also possible to exchange electronic data with one terminal without going through the network.

In an electronic data storage system having a cluster configuration composed of a plurality of data storage servers, when there is a server to which the external device 30 is not mounted and the authentication code verification is performed on the unmounted server, the electronic data that requires the authentication code verification It is also possible to perform verification of the authentication code by mounting the external device mounted on the server that has generated the X authentication code and the electronic signature to the unmounted server .

1 is a schematic block diagram showing a configuration example of an evidence-proof electronic data storage system 1 according to a first embodiment of the present invention. It is a figure which shows the example of a recording of the electronic data stored in the storage data recording part 80 of FIG. It is a figure which shows the structural example and data example of a policy table currently recorded on the policy table recording part 82 of FIG. It is a figure which shows the example of a structure and data example of the log data preserve | saved in the log table recording part 84 of FIG. It is a flowchart which shows the procedure until the server operation start by this invention. It is a correlation chart which shows the flow of the data and the process in the mutual authentication which the evidence-proof electronic data storage system of this invention performs. It is a flowchart which shows the operation | movement which produces | generates an authentication code by the 1st Embodiment of this invention. It is a flowchart which shows the authentication code collation procedure by the 1st Embodiment of this invention. It is a flowchart which shows the log filter operation | movement by the 1st Embodiment of this invention. It is a flowchart which shows the operation | movement which divides | segments electronic data by the 2nd Embodiment of this invention, and produces | generates an authentication code for every division | segmentation data. It is a figure which shows the structural example of each data stored by the storage data recording part 80 by the 2nd Embodiment of this invention. It is a schematic block diagram which shows the structural example of the evidence guarantee type | mold electronic data storage system 2 which consists of a some electronic data storage server by the 3rd Embodiment of this invention. It is a rough block which shows the structural example of the electronic data storage server 10b provided with the two external devices 30 and 30a by the 4th Embodiment of this invention. It is a block which shows the typical structural example of the evidence data type electronic data storage system by a prior art.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Electronic data storage system of this invention 2 Electronic data storage system of the cluster structure of this invention 10 Data storage server 10 of this invention
11, 60 CPU
12, 70 ROM
13, 62 RAM
14 Communication Interface 15 External Device Interface 16 Input / Output Interface 17 Secondary Storage Device 20 Input / Output Device 30 External Device 30
40 ROM40
70 Hash function calculation object 72, 75 Authentication code generation object 80 Storage data storage unit 82 Policy table 84 Log table 90 Data storage program 92 Data read program 94 Access restriction 96 Authentication code verification 98 Log filter 920 Client

Claims (11)

An electronic data storage system that guarantees the evidence of electronic data with an authentication code and an electronic signature,
At least one server capable of sending and receiving electronic data with an external client and electrically and mechanically coupled to an external device;
An external device comprising a ROM area, a RAM area, and a CPU, and connected to the server via an interface;
A private key is burned into a storage area that is not rewritable by the manufacturer at the time of manufacture, and access-restricted read-only storage means is provided,
It said external device comprises a software means for generating a temporary private key based on the secret key that was copied from the read-only storage unit to the ROM region, the CPU is caused based on the previous SL software means further only the number of random numbers one o'clock to generate a private key, at least a portion of the end of the one o'clock secret key generated and stored in the RAM area, and generates an authentication code from said one o'clock secret key and a given electronic data program Prepared in the ROM area as an encapsulated object,
The server
Means for reading the software means, the object, and the temporary private key;
Reading said software means, said object, and using the one o'clock secret key, an authentication code generating object for generating an authentication code before Symbol electronic data,
An electronic signature generating means for generating an electronic signature by encoding the electronic data with a secret key;
An electronic data storage system comprising: storage means for storing the electronic data , the generated authentication code, and the generated electronic book name .   2. The electronic data storage system according to claim 1, wherein the read-only storage means is stored by a third party who has no interest in both the administrator of the server and the client.   2. The electronic data storage according to claim 1, wherein the server further comprises a verification object for verifying the authentication code of the electronic data stored in the storage unit using the authentication code generation object. system. The server
2. The electronic data storage system according to claim 1, further comprising means for restricting access to the object based on the policy table, the policy table comprising policy records that define access restrictions. The authentication code generation object discharges a log each time it is activated,
2. The electronic data storage system according to claim 1, wherein the server includes means for storing the log in a predetermined storage area.   When the server receives a predetermined command together with designation of one time zone, the server further comprises means for erasing a log that matches the condition of any policy record in the policy table among logs collected in the time zone. The electronic data storage system according to claim 4.   The server further includes means for outputting a visual alarm, an audible alarm, or both of the alarms with respect to a log that has not been deleted among logs collected in the time period. The electronic data storage system according to claim 6. The electronic data storage system includes a plurality of servers and a secondary storage device shared by the plurality of servers,
The electronic data storage system according to claim 1, wherein the secondary storage device has an electronic data storage area for storing electronic data of all servers, and each of the plurality of servers does not have the storage means. . The server includes a second external device, stores a second secret key different from the secret key of the first external device in a RAM area,
In addition to the software means, the object, and the temporary secret key read from the first external device, the authentication code generation object includes a second software means read from the second external storage device, a second objects and second temporary using a secret key, before Symbol electronic data storage system of claim 1, wherein the generating an authentication code of the electronic data. The server includes a dividing unit that divides the electronic data into a plurality of divided data before generating an authentication code of the electronic data,
The electronic data storage system according to claim 1, wherein the authentication code generation object generates an authentication code for each piece of divided data. The dividing means divides the electronic data into a plurality of variable length divided data,
11. The electronic data storage system according to claim 10, wherein the storage means includes means for storing the authentication code and information indicating the length of the variable length divided data for each variable length divided data.

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