| 摘要 |
PROBLEM TO BE SOLVED: To provide an encryption method, etc., capable of improving security more than in the conventional manner. SOLUTION: A encryption key generator 27 uses a plurality of pieces of information to generate a encryption key. A unitization device 23 unitizes input information, an encryption control information recorder 24 attaches encryption control information for specifying a plurality of pieces of information to be the base for a encryption key, and an encryptor 25 encrypts the encryption control information. In decoding unitized encryption information, encryption control information held in each unit is used to specify the information to be the base for a encryption key for the unit, a encryption key is generated from the information to be the base for the encryption key for the unit, and the encryption key is used to decode the encryption information. |
