JP2000101564A - Ciphering system and recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make analyzing of a decoding key impossible and to recognize a proper communicating party by repeating ciphering a random number to an opposite party, decoding it and updating an original key by the random number. SOLUTION: A user terminal 11 ciphers data by a part of the key read from a card 14, transmits them, receives the data returned corresponding to the transmission, decodes transmission data by a part of the key and decodes the received data (random number) by the other part of the key. Then, the key is updated by the decoded random number and written to the card 14. Also, a computer center 1 decodes the received data by a part of the key, ciphers the transmission data for the decoded data by a part of the key, transmits them, generates the random number, ciphers it by the other part of the key, transmits it, updates the key by the random number and preserves it.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an encryption system for encrypting data and a recording medium.

[0002]

2. Description of the Related Art Conventionally, when data is exchanged between a center operated by a user and a center via a line or a network, the data is encrypted and transmitted to the other party, and the receiving side decrypts the original data. The data was kept confidential.

[0003]

The above-mentioned conventional DES
In such an encryption method, a predetermined key (for example, a public key and a secret key) is provided, data is encrypted with the key (for example, a public key) and transmitted to a line or a network, and the key (for example, a secret key) is received on the receiving side. To generate the original data,
Although secret communication is being performed, if a third party obtains encrypted information on the line or during transmission on the network, the key is decrypted by repeating decryption a number of times using the regularity of the data as an end condition. However, there is a problem that it is highly possible that the transmitted data is decrypted with the key obtained by decrypting the data. For this reason, there is a demand for encryption in which the termination condition is unknown even if encrypted information is being transmitted through a line or network.

[0004] The present invention solves these problems,
Repeat the process of encrypting the random number, transmitting it to the other party, decrypting it, and updating the original key with the random number repeatedly, making it impossible to decrypt the key for decryption and enabling the recognition of the legitimate communication partner. The purpose is.

[0005]

Means for solving the problem will be described with reference to FIG. In FIG. 1, a computer center 1 is a center that provides various services to a large number of user terminals 11.

[0006] The user terminal 11 is connected to the computer center 1.
To request the provision of various services.
The card 14 stores and stores a key updated with a random number.

Next, the operation will be described. The user terminal 11 encrypts the data with a part of the key read from the card 14, transmits the data, receives data returned in response to the transmission, decrypts the transmission data with a part of the key, and receives the received data ( The random number) is decrypted by the other part of the key, and the key is updated with the decrypted random number and written to the card 14.

Further, the data received by the computer center 1 is decrypted with a part of the key, transmission data corresponding to the decrypted data is encrypted with a part of the key and transmitted, and a random number is generated and encrypted with another part of the key. And the key is updated with a random number and stored.

At this time, at least one of the hardware unique information, the software unique information, and the authentication program unique information of the user terminal 11 is hashed and its value is encrypted by a part of the key read from the card 14. To the computer center 1 to authenticate the user terminal 11.

Further, a part of the key and another part of the key are a first half and a second half of the key, or a second half and a first half of the key. Also, as updating the key with a random number, a new key is generated by adding the random number to the key, and is stored in the card 14 or the like.

When the user terminal 11 receives transmission data, the key is updated in synchronization with the user terminal 11 and the computer center 1. Further, every time the key is updated, the key in the user's card 14 is updated on the user terminal 11 side.

Therefore, the random number is encrypted, transmitted to the other party and decrypted, the original key is updated with the random number, and the hardware unique information and software unique information of the user terminal 11 and one of the contents of the authentication program itself are obtained. By encrypting and transmitting one or more of them and authenticating the user terminal 11, it becomes possible to make it impossible to decrypt the key for decryption and to make it possible to recognize the communication partner.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment and operation of the present invention will be sequentially described in detail with reference to FIGS.

FIG. 1 shows a system configuration diagram of the present invention.
In FIG. 1, a computer center 1 is a center that provides various services to a large number of user terminals 11, and here is composed of a delivery system 2, a key management system 3, a random number generation system 4, and the like. is there.

The delivery system 2 performs various deliveries, such as encrypting and transmitting a random number for updating a key (key) and transmitting data after encrypting the data with a key (key).
The key management system 3 manages keys (keys).

The random number generation system 4 generates a random number. The user terminal 11 connects to the computer center 1 and requests the provision of various services.
Here, the terminal automatic recognition means 12, the cumulative random number management means 1
3, a card 14, and the like.

The terminal automatic recognition means 12 automatically recognizes a terminal. The cumulative random number management means 13 updates and manages keys based on random numbers. Card 14
Is a medium for storing and storing a key updated with a random number, and is a medium such as an IC card or a floppy disk.

The network 21 is various networks (networks) such as a public line. Next, a procedure for generating a user card and an administrator card based on the configuration of FIG. 1 will be described in detail according to the order of the flowchart of FIG.

FIG. 2 shows a flowchart (card generation) for explaining the operation of the present invention. In FIG. 2, S1 generates an administrator random number (R1) at a center (computer center).

In step S2, a random number is stored in the card. This is because the random number (R1) generated in S1 is stored in the administrator card 32.
To be stored. In S11, the administrator sets up the card. That is, in S2, the computer center 1 writes a random number (R1) in the manager card 32 in the computer center 1, and the manager who has brought the random number (R1) inserts it into the card reader of the user terminal 11 to read it.

In step S12, hardware-specific information is obtained. The hardware-specific information includes, for example, the manufacturer, model number, firmware version and serial number of the hard disk (for example, the hard disk of drive C in Windows) for booting the OS (operating system), and the hardware of the user terminal 11 such as the MAC address of the LAN connection mechanism. This is information unique to the ware.

In step S13, software-specific information is obtained. The software unique information is information unique to the software of the user terminal 11, such as a product number, an initial installation date, and a time.

In step S14, the contents of the hardware + software + authentication program itself are hashed. This is the hardware unique information of the user terminal 11 acquired in S12, S13
In the software specific information of the user terminal 11 acquired in
The content of the authentication program itself is added and hashed (from the hashed value, it is difficult to identify the original content).

In step S15, using the latter half of the random number (R1) as a key, the hash value, the manager ID and the date / time are encrypted, and the manager ID and the date / time are added and transmitted. This is based on the key (random number (R
Using the second half of (1)) (for example, the last 128 bits of the 256-bit key) as a key, the value hashed in S14, the administrator ID, and the date / time are encrypted, and the
D, adding the date and time and transmitting to the computer center 1.

In step S4, the computer center 1 that has received the data transmitted in step S15 uses the DB based on the administrator ID.
The received data is decrypted using the latter half of the above random number (R1) as a key, and a hash value, an administrator ID, and a date / time are generated.

In step S5, the date and time are compared with the administrator ID decrypted in step S4. If OK, proceed to S6. In the case of NG, the process ends with no user qualification. In S6, the hash value is encrypted with the center common key and stored in the DB (user specific information 33).

In step S7, random numbers (R2, R3) are generated.
This generates a random number (R2) for the user and a random number (R3) for the administrator. In S8, the random number (R2, R3) generated in S7 is encrypted with the first half of the random number (R1) (key). Then, it transmits to the user terminal 11.

In S9, random number accumulation (random number (R2) + random number (R1) → key (user key)) is performed. S10 is
Random number accumulation (random number (R3) + random number (R1) → key (key for manager)) is performed.

In step S11, the key for the user and the key for the administrator are encrypted and stored in the DB using the center common key. As a result, the user key and the administrator key are encrypted and stored in the key management DB 34 with the center common key.

In S16, the encrypted data transmitted in S8 is received, and the random numbers (R2, R3) are replaced with the random numbers (R1).
Decrypt in the first half of (key). In S17, random number accumulation (random number (R2) + random number (R1) → key (user key)) is performed.

In S18, random number accumulation (random number (R3) + random number (R1) → key (key for administrator)) is performed. S19 is
The user key is written on the user card 35. As a result, the key in the user card 35 becomes a random number (R2).
It becomes possible to generate a user key by accumulating a random number (R3) in the (key) and write it to the user card 35.

In step S20, the manager key is written into the manager card 32. This allows the key in the manager card 32 to accumulate the random number (R1) (key) with the random number (R3), generate a manager key, and write it to the manager card 32. As a result, even when the administrator performs setup with another user terminal, a user key for another administrator can be created.

As described above, the administrator writes the random number (R1) into the administrator card 32 and brings it with him. When the new user terminal 11 is set up, the hardware unique information, the software unique information, and the authentication of the user terminal 11 are set. Hash the contents of the program itself for hash value and administrator I
D, the date and time are encrypted using the latter half of the random number (R1) as a key and transmitted to the computer center 1;
D is compared with the date and time, and when OK, the hash value is encrypted with the center common key and stored, and the random number (R
2, R3) is generated, encrypted in the first half of the random number (R1) (key), transmitted to the user terminal 11, and the random number is accumulated (random number (R2) + random number (R1) → key (user key).
Is updated to random number (R3) + random number (R1) → key (administrator key)), and encrypted and stored in the key management DB 34 with the center common key. on the other hand,
The user terminal 11 also decrypts the data transmitted from the computer center 1 with the first half of the key and performs random number (R2, R2
3) is obtained, and similarly, random number accumulation (random number (R2) + random number (R1) → key (user key) is updated, and random number (R3) + random number (R1) → key (administrator key) )), And the user card 35 and the administrator card 32
Can store each key.

Next, the procedure when the user terminal 11 makes an inquiry to the computer center 1 based on the configuration of FIG. 1 will be described in detail according to the order of the flowchart of FIG. FIG. 3 shows a flowchart (inquiry) for explaining the operation of the present invention.

In FIG. 3, S41 inputs an inquiry key. In this case, the user operates the user terminal 11 to input an inquiry key (a key for inquiring the computer center 1 (a key for search)) by key input or by selecting it from the screen.

In step S42, hardware-specific information is obtained. The hardware specific information includes, for example, the manufacturer, model number, firmware version and serial number of the hard disk (for example, the hard disk of drive C in Windows) for booting the OS (operating system), and the MAC address of the LAN connection machine number. This is hardware-specific information.

In step S43, software-specific information is obtained. The software unique information is information unique to the software of the user terminal 11, such as a product number, an initial installation date, and a time.

In step S44, the contents of the hardware + software + authentication program itself are hashed. This is the hardware unique information of the user terminal 11 acquired in S42,
In the software specific information of the user terminal 11 acquired in
The contents of the authentication program itself are added and hashed (to an arbitrary value within a predetermined range).

In step S45, the hash value, the user ID and the date / time are encrypted using the latter half of the user key as a key, and the user ID and the date / time are added and transmitted. This corresponds to the key read from the user card 35 (S in FIG. 2).
Using the latter half of the key (the key written in step 19) (for example, the last 128 bits of the 256-bit key) as a key, the value hashed in S44, the user ID, and the date / time are encrypted.
A user ID, date and time are added to the information, and the result is transmitted to the computer center 1.

In step S21, the computer center 1 which has received the data transmitted in step S45 has a D based on the user ID.
The received data is decrypted using the latter half of the user key on B as a key, and a hash value, a user ID, and a date / time are generated.

In step S22, the user ID decrypted in step S21 is compared with the date and time. If OK, proceed to S23. N
In the case of G, the process ends as there is no user qualification. S23
Decrypts the user unique information on the DB with the center common key.

In step S24, the hash values are collated. This is done by checking whether the hash value received from the user in S21 and decrypted in the second half of the user key matches the hash value obtained by decrypting the user-specific information in the DB of the center with the center common key. . If OK, proceed to S25. In the case of NG, the process ends with no use qualification.

In step S25, a random number (Rn) is generated. This generates a random number (Rn) for updating the user key. In S26, the random number (Rn) generated in S25 is encrypted with the first half of the user key. Then, it transmits to the user terminal 11.

In step S46, the data transmitted in step S26 is received by the user terminal 11, and the random number (Rn) is decoded by the first half of the user key. Thereby, the computer center 1
The random number (Rn) generated in the above is encrypted with a dedicated independent key (the first half of the user key), transmitted, and decrypted on the receiving side. Since (Rn) is encrypted with the first half of the user key and transmitted, the termination condition is unknown even if a large number of decryption attempts are made (the data is random and the regularity is unknown and the decryption ends) Condition is unknown), it becomes logically impossible to decrypt the decryption key, and the reliability can be improved.

In step S47, the inquiry key is encrypted in the latter half of the user key. Then, the data is transmitted to the computer center 1. In S27, the encrypted inquiry key transmitted in S47 is received, decrypted, and searched.

In step S28, the search result is encrypted with the latter half of the user key and a response is made. In S48, the answer data of the search result transmitted in S28 is decrypted (decoded in the latter half of the user key), and the answer data is displayed on the screen.

In step S49, the user terminal 11 performs a termination process. In step S29, the computer center 1 performs a termination process. In these steps S49 and S29, both the user terminal 11 and the computer center 1 synchronize and confirm the end of the inquiry operation using a series of inquiry keys.

In S50, the user terminal 11 performs random number accumulation (random number (Rn) + user key → user key). S
Reference numeral 51 updates the user key (writes and updates the new user key on the user card). Thus, for each inquiry, the new user key after the random number (Rn) transmitted from the computer center 1 is accumulated in the user key read in S45, is written in the user card 35. Will be updated.

In S30, the computer center 1 accumulates random numbers (random number (Rn) + user key → user key). In step S31, the user key is updated (the new user key is encrypted and stored in the DB using the center common key). Thus, every time the user terminal 11 makes an inquiry, the key management DB 34 stores the new user key obtained by accumulating the random number (Rn) generated by the computer center 1 in the user key read in S33. It will be written and updated after being encrypted with the common key.

As described above, when the user operates the user terminal 11 to make an inquiry, a hash value is generated based on the hardware unique information and software unique information of the user terminal 11 and the contents of the authentication program itself. Then, the latter half of the user key read from the user card 35 is encrypted, the user ID is added to the date and time, and the date and time are transmitted to the computer center 1. The computer center 1 receives the user ID of the received data. In the latter half of the user key corresponding to the date / time, decryption is performed, the user ID is verified against the date / time to authenticate the user terminal 11, and when OK, the hash value is further verified and used. Authenticates the user, generates a random number (Rn) when OK, encrypts it with the first half of the user key, transmits it to the user terminal 11, and receives it for the user at the user terminal 11. And it holds the decoding in the first half of the over. Then, the inquiry key is encrypted in the latter half of the user key and transmitted to the computer center 1 for decryption.
A search B is performed, and the search result data is encrypted with the latter half of the user key and transmitted to the user terminal 11. The received data is decrypted by the latter half of the user key and displayed on the screen. When the inquiry is completed, the user terminal 11 accumulates the stored random number (Rn) in the user key, generates a new user key, writes it in the user card 35, and updates it. On the other hand, the computer center 1 also accumulates the random number (Rn) held in the same manner in the user key, generates a new user key, writes it in the key management DB 34, updates it, and synchronizes. Then, the user key is updated. In addition, the new user key is a random number (R
n) is generated by accumulating, but is not limited to this, the user key is updated to a different random value every time by a random number (Rn) by some method (for example, a method such as four arithmetic operations or functions other than accumulation). What should I do?

[0051]

As described above, according to the present invention,
The random number is encrypted, transmitted to the other party, decrypted, the original key is updated with the random number, and the hash value is obtained based on at least one of the hardware unique information of the user terminal, the software unique information, and the content of the authentication program itself. Is generated, encrypted, transmitted, and confirmed by the other party, so that the decryption of the key for decryption is disabled, and the legitimate communication party can be recognized.

Also, if a user card is used even if it is copied, using a regular user card will render the user unqualified. I understand. Thus, a key (eg a secret key)
Full encryption and authentication is possible even for internal crimes of those who can know.

[Brief description of the drawings]

FIG. 1 is a system configuration diagram of the present invention.

FIG. 2 is an operation explanatory flowchart (card generation) of the present invention.

FIG. 3 is a flowchart (inquiry) for explaining the operation of the present invention.

[Explanation of symbols]

 1: Computer center 2: Delivery system 3: Key management system 4: Random number generation system 11: Terminal for user 12: Terminal automatic recognition means 13: Cumulative random number management means 14: Card

Continued on the front page (72) Inventor Kunio Yamagishi 2-45, Aomi, Koto-ku, Tokyo F-term within Fujitsu FIP Co., Ltd. (Reference) 5J104 AA07 AA16 EA01 EA18 EA22 JA03 KA01 KA04 KA06 MA02 MA06 NA02 NA05 NA35 PA07

Claims (9)

[Claims] 1. An encryption system for encrypting data, means for encrypting and transmitting data with a part of a key, receiving data returned in response to the transmission, and transmitting data with a part of the key And a means for receiving data returned in response to the transmission and updating the key with a random number decrypted by another part of the key on the terminal side. method. 2. An encryption method for encrypting data, means for decrypting received data with a part of a key, means for encrypting transmission data corresponding to the decrypted data with a part of the key and transmitting the data, Means for generating and transmitting the encrypted key with another part of the key and updating and storing the key with the random number. 3. One of hardware specific information, software specific information, and authentication program specific information of the terminal.
2. The encryption method according to claim 1, wherein means for hashing one or more of the keys, encrypting the value with a part of the key, and transmitting the encrypted value to the center is provided on the terminal side. 4. The key according to claim 1, wherein the part of the key and the other part of the key are a first half and a second half of the key, or a second half and a first half of the key. The encryption method according to claim 3. 5. The encryption method according to claim 1, wherein, as updating of the key by the random number, a new key is generated by accumulating the random number in the key. 6. The encryption device according to claim 1, wherein when the terminal receives the transmission data, the key is updated in synchronization with the terminal and the center. method. 7. The terminal according to claim 1, wherein the key in the user card is updated on the terminal side every time the key is updated.
7. The encryption method according to any one of 4, 5, and 6. 8. A means for encrypting and transmitting data with a part of a key, a means for receiving data returned in response to the transmission and decrypting transmission data with a part of the key, and A computer-readable recording medium on which a program for receiving data returned as a function of updating the key with a random number decrypted by another part of the key is recorded. 9. A means for decrypting received data with a part of a key, means for encrypting transmission data corresponding to the decrypted data with a part of the key and transmitting the same, and generating a random number and another part of the key A computer-readable recording medium storing a program that functions as a means for encrypting and transmitting the key and updating and storing the key with the random number.