Abstract

A) is computed as a common secret key by a shared secret key computation section. An encryption/decryption device is thereby capable of rapid generation of the secure common secret key.

IPC Classes  ?

• H04L 9/08 - Key distribution
• H04L 9/06 - Arrangements for secret or secure communicationsNetwork security protocols the encryption apparatus using shift registers or memories for blockwise coding, e.g. D.E.S. systems

Abstract

2 into bit sequences, and joins these to the bit sequences W1, W2. The encryption device repeats the operation of the non-convertible matrices and the non-linear transformation until the respective numbers of bits of the bit sequence W1 and the bit sequence W2 have reached a number of bits of a bit sequence expressing encryption target data. The encryption device derives a pseudo-random number bit sequence by computing the exclusive logical sum between the bit sequence W1 and the bit sequence W2, and performs encryption using the pseudo-random number bit sequence. The encryption device is thereby able to increase the speed of encryption processing and to increase the cryptographic strength in cases in which the number of bits of the encryption target data is modifiable.

IPC Classes  ?

• H04L 9/08 - Key distribution
• H04L 9/06 - Arrangements for secret or secure communicationsNetwork security protocols the encryption apparatus using shift registers or memories for blockwise coding, e.g. D.E.S. systems

Abstract

A public data acquisition section (22) acquires public data that includes a prime number p, a natural number d, a matrix Q, and a matrix S. A secret key generation section (24) generates a secret key that includes natural numbers nA and kA. A non-commutative matrix generation section (26) calculates a matrix MA (MA = S-kAQnASkA), sends the matrix to a communication partner, and acquires a matrix MB (MB = S-kBQnBSkB) from the communication partner. A shared secret key calculation section (28) calculates a matrix MAB (MAB = S-kAMBnASkA) as a shared secret key. As a result, the encryption and decryption device can quickly generate a secure shared secret key.

IPC Classes  ?

• H04L 9/08 - Key distribution
• H04L 9/20 - Pseudorandom key sequence combined element-for-element with data sequence

Abstract

On the basis of private data (A) and prime numbers (p1, p2), an encryption device generates noncommutative matrices (A1, A2) (100) and applies the noncommutative matrices (A1, A2) to vectors (vi1, vi-12) (104). The encryption device carries out a nonlinear conversion on the vector (vi1) and the vector (vi2), converting same to bit strings, and bonds same with bit strings (W1, W2) (106, 108). The encryption device repeats the application of the noncommutative matrices and the nonlinear conversion until the number of bits of the bit string (W1) and the bit string (W2) reach a number of bits of a bit string which represents data to be encrypted (110). The encryption device calculates an exclusive OR (XOR) of the bit string (W1) and the bit string (W2), derives a pseudorandom bit string (112), and carries out encryption using the pseudorandom bit string. Thus, it is possible for the encryption device to accelerate an encryption process and strengthen encryption breaking resistance when a number of bits of data to be encrypted is variable.

IPC Classes  ?

• H04L 9/20 - Pseudorandom key sequence combined element-for-element with data sequence