| 摘要 |
<P>PROBLEM TO BE SOLVED: To prevent a key from being wrongfully decoded by DPA. <P>SOLUTION: An IC card includes an encryption operator 23 which manages a key for use in decryption of data encrypted and transmitted from a reader/writer or in encryption of data to be transmitted to the reader/writer and uses the managed key to encrypt or decrypt data. The encryption operator 23 is reconfigured at a prescribed timing of encryption of data, decryption of data, or the like. This invention is applicable to IC cards which use keys to decrypt encrypted data and encrypt data. <P>COPYRIGHT: (C)2007,JPO&INPIT |
