| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a counter measure for opposing to an incorrect search for reading a built-in encryption key by performing some operations to such a device like an IC card. <P>SOLUTION: A key register 13 provided to a cipher processor 12 stores its error correction code together with the encryption key. An error correction circuit 15 corrects an error generated to the encryption key before a cipher processing unit 16 performs a cipher processing. Since this makes it possible for bit errors to be corrected even when these errors are generated after each of bits of the encryption key is operated intentionally by an adversary, results of the operations cannot be realized. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
