| 摘要 |
PROBLEM TO BE SOLVED: To improve the safety of a compressibility function using a Feistel cipher.SOLUTION: An input unit 10 accepts, as its input, plaintext and a key. A key schedule unit 11 generates r random numbers on the basis of an inputted initial-value constant. A constant-embedding unit 12 generates r sub-keys by inserting each of r different embedding constants into a predetermined bit position in each of the r random numbers. A round function arithmetic unit 13 generates, for the inputted plaintext, ciphertext by repeatedly calculating a round function r times by using the r sub-keys. A hash value generation unit 14 calculates an exclusive-OR of the ciphertext and plaintext and generates a hash value. An output unit 15 outputs the hash value. |
