ENCRYPTOR, ENCRYPTING METHOD, DECRYPTOR, DECRYPTING METHOD, AND COMPUTER READABLE RECORDING MEDIUM HAVING PROGRAM STORED THEREIN

摘要

In order to encipher data while enciphering other data, a memory (55) is arranged in parallel to a feedback line (65) for feedback to a selector (54) from an enciphering module (51) using an encryption key (K). If an interrupt (IT) for processing plaintext block data (N~i?) occurs during the processing of plaintext block data (M~i?), the cryptogram block data (C~i?) being in process when the interrupt (IT) occurs is stored in a register (56). When th e processing of the plaintext block data N~i? is completed, a selector (54) selects the cryptogram block data (C~i?) stored in the memory (55), and the processing of plaintext block data (M~i?+1) is started.