ENCRYPTION SYSTEM, ENCRYPTION DEVICE, DECRYPTION APPARATUS, ENCRYPTION METHOD, AND PROGRAM

PROBLEM TO BE SOLVED: To provide an encryption system which shortens the length of a cipher text and needs no one time signature to guarantee the whole integrity, when performing multiple encryption under a plurality of conditions. SOLUTION: The encryption system is a multiple encryption system which performs N times of encryption, and includes at least an encryption device and a decryption apparatus. The encryption device includes an encryption input unit, a random number generation unit, a cipher processing part, and a cipher text output unit. In this system, N pieces of encryptor are connected in tandem. Random numbers used by each encryptor are converted according to a predetermined rule whose confirmation is possible when decoding. And when decoding, it is confirmed that encryption is performed with the random numbers converted according to the predetermined rule. COPYRIGHT: (C)2011,JPO&INPIT