JPS6095475A - Key generation system for cryptographer - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention (a) Technical Field of the Invention The present invention relates to a data line terminating device installed at each end of a communication path and a data terminal device connected to the data line terminating device for data transmission. A public key distribution method (
Pui+1ic Key DistributionS
The present invention relates to an encryption device that encrypts signals sent from the data terminal device using PKDS (PKDS), which shortens the time occupied by a communication channel necessary for public key distribution without using particularly expensive dedicated arithmetic circuits. This invention relates to a key generation method for a cryptographic device.

(b) Prior art and problems When transmitting data between computer systems using a communication channel, or when transmitting data by connecting a terminal device to a computer system via a communication channel, the information to be transmitted is encrypted. may be used to transmit data. In this case, there is a key required to encrypt/decrypt information, and it is necessary to exchange the key between the encryption devices installed at both terminal stations.

One of these key exchange methods is a public key distribution method. A key generation method for a cryptographic device that performs key distribution using a conventional public key distribution method will be described with reference to FIG.

FIG. 1 is a diagram illustrating a key generation method using a public key distribution method. The data sent from the data terminal device 1 is encrypted with 111 by the encryption device 2, converted into ri '77 suitable for transmission over the communication path by the data line termination device 3, and sent out. The signal that has arrived is converted into the original encrypted data, enters the encryption device 5, is decrypted, and is sent to the data terminal device 6.The data sent from the data terminal device; ηG is processed in the same manner as above. The encryption device 2 generates a private key α using the public key distribution 1 as l-'J.
! Perform the calculation of X.

That is, it is an operation of X-symptom' (modn), which is an operation in which M is raised to the α power and divided by n. Since it is very time consuming and difficult to calculate α from X with this (,1 one-way function), even if this It is called x4-public key. And this X goes through JM faith l18 and becomes 1lfi adventure fFi! Delivered on 5th. When the cryptographic device 5 receives this X, it generates a private key β and performs the function of the public key Y as W Y = Mp(llIoiI n
) and delivers the public key Y to the cryptographic device 2. lli
, 'J When the device 2 receives this Y, it performs an operation on the common key. That is, K = Y” (mod n) =
M”(mod n >. When the cryptographic device 2 receives the public key Y, it sends an acknowledgment to the cryptographic device 5, and the cryptographic device 5 also performs an operation on the common key. That is, =Xβ(nod n
) = M" (mod n). The method of encrypting/decrypting using this common key K is the public key distribution method. Here, public 131!
) and Mp (mod n) are calculated using M, α
, when n is about 100 pips, the color changes for several seconds to 10 seconds when carried out using a microprocessor. Therefore, the time required for one-time public key distribution is about 10 to 20 seconds, which is very long and the time required to occupy the color change channel, which is not practical. So public fM! In order to increase the calculation speed, dedicated LSIs are used, or general-purpose high-speed processors are combined with innovative calculation methods. However, dedicated LSIs and high-speed processors are expensive and have the disadvantage that they are not used often and are not economical.

(C) Object of the Invention In order to eliminate the above-mentioned drawbacks, the object of the present invention is to provide a key generation method for a cryptographic device that does not require the use of an expensive dedicated arithmetic circuit and shortens the time required to occupy a communication channel necessary for public key distribution. It is about providing.

(d) Structure of the Invention The structure of the present invention is to generate a plurality of secret keys in an encryption device that uses a public key distribution method to encrypt/fit9 information transmitted via a communication path. A table is set up in which a plurality of public keys corresponding to each key are computed and stored, and the public key is distributed between the cryptographic devices from the table according to predetermined instructions, and the distributed public key and the public key are Share based on i+11 tiH! control to store the calculation result in the table corresponding to the private key of the table, and perform the calculation of the public key and the common key by referring to the table during the processor's idle time. It is intended to be controlled.

(e) Embodiments of the Invention The present invention does not perform the exponentiation operations M'' (mod n) and Mp (mod n), which require a lot of time in public key distribution, by providing them in the cryptographic device using a public key distribution instruction. By executing the public key using the idle time of the microprocessor currently in use, storing Vli in non-volatile memory and transmitting it as appropriate, the time occupied by the communication channel is shortened.Also, it is possible to send multiple public keys in one transmission. This allows multiple common keys to be generated for multiple private keys.

FIG. 2 is a diagram for explaining the control method of the present invention, and FIG. 3 is a diagram for explaining a table according to an embodiment of the present invention. This will be explained using FIGS. 2 and 3. The operations of the data terminal equipment 1.6 and the data line termination equipment 3.4 are similar to those shown in FIG.

The cryptographic device 7 generates a secret key α1 using a random number generated by a built-in microprocessor or random number generation circuit. α2.
. . . αn is stored in the secret key area of table A configured in non-volatile memory as shown in FIG. Further, the encryption device 8 generates private keys β1, β2, . ...β
n is stored in the secret key area of table B configured in non-volatile memory as shown in FIG. Based on the random numbers, that is, the private keys α1 to αn, the microprocessor of the cryptographic device 7 generates the public keys xl, x2, .
...Xn is calculated and the public key area of table A is secret &) I! α1゜α2. ...Stored corresponding to αn.

In addition, the microprocessor of device No. 1lff lY+'8 calculates the public keys Y,, Y2,...Yn based on the random numbers 1111''5 private keys ρ1 to βn during idle time, and calculates the public keys of table I3. private keys β1, β2 in the area of
．． ...Stored corresponding to βn. According to a predetermined procedure, for example, when device 7 receives a public key distribution instruction, it reads out public keys XI, X2, -Xn from table 8, and
ll'9 Delivered to device f8. The encryption device 8 receives the delivered public keys X1, X2. ...Xn in the other party's public key area of table B as the private key β1. β2. ...Stored in accordance with βn.

Then, from table B, public key Y1. Y2. ...Reads Yn and delivers it to the encryption device 7. The encryption device 7 stores the delivered public keys YI+Y2+...Yn in the other party's public key area of table A as the private key α1. α2. ...Stored corresponding to αn. Encryption device number 7: 1 public key Yl.

Y2. ...When Yn is received, an acknowledgment is sent to the cryptographic device 8, and the public key distribution operation is completed. Therefore, the occupation of the communication path can be extremely small since the time required to mutually send out a plurality of public keys is sufficient. The microprocessor of the cryptographic device 7 uses the free time to publish the other party from table A 63! Y+
, Y2 , . . . Yn and secret keys α1, α2 . ...α
n is sequentially read out and 2, .・
...Stored corresponding to αn.

Also, the 80 microprocessor in 11flJ uses the free time to retrieve the other party's public keys Xl, X2゜...X from table B.
n and private key β1. β2, . . . βn are read out sequentially and used as a common key, 2. . . . Kn is calculated, and the secret key β1 . β2. ...Stored corresponding to βn. Until 2+ .

Further, switching between the common keys Kl, 2°, . . . Kn can be performed by an instruction from the encryption device 7 or 8.

(f) As described in detail, the present invention does not require the use of expensive dedicated arithmetic circuits, and is capable of public key distribution that requires only a short time for occupying a communication channel. Multiple public keys can be distributed.

[Brief explanation of drawings]

FIG. 1 is a diagram for explaining a key generation method using a public key distribution method, FIG. 2 is a diagram for explaining a control method of the present invention, and FIG. 3 is a diagram for explaining a table according to an embodiment of the present invention. 1.6 is a data terminal device, 2.5.7.8 is an encryption device,
3.4 is a data line termination device. 3rd Tape'/L, 4,000-B) LB

Claims (1)

[Claims] A 11η device that encrypts/decrypts information transmitted via a communication channel using a public key distribution method generates a plurality of private keys and calculates a plurality of public keys corresponding to the plurality of private keys. A table is provided in which public keys are stored, and a public key is distributed between the encryption devices from the table according to predetermined instructions, and the distributed public key and the calculation result of a common key based on the public key are stored in the secret of the table. A cryptographic device, characterized in that it is controlled to be stored in the table in accordance with the key, and the calculation of the public key and the common key is performed by referring to the table during idle time of processor operation. Key generation method.