ENCRYPTING DEVICE, DECRYPTING DEVICE, ENCRYPTING PROGRAM, DECRYPTING PROGRAM, RECORDING MEDIUM STORING THE ENCRYPTING PROGRAM, RECORDING MEDIUM STORING THE DECRYPTING PROGRAM, ENCRYPTING METHOD, DECRYPTING METHOD AND TABLE CREATING METHOD

摘要

PROBLEM TO BE SOLVED: To reduce data storage quantity required for encryption processing or decryption processing while concealing keys, in encryption processing using a plurality of keys. SOLUTION: An encryption processing selecting section 700 reads a list corresponding to a key number 720 indicating the number of encryption processing used for encryption from a list 710 of encryption table use order indicating an order of using tables used for encryption, and gives the read list to an encrypting section 702. The encrypting section 702 encrypts plane text data 722 to be encrypted while referring to an individual table 712 used for each key and a common table 714 commonly used for all the keys on the basis of the list given from the selecting section 700. Then, the encrypting section 702 outputs the encrypted data 724 and the key number 720 used in the encryption in association with each other. COPYRIGHT: (C)2008,JPO&INPIT