| 摘要 |
PROBLEM TO BE SOLVED: To provide a data processor with a security function capable of secretly holding a parameter written from the outside part for encipherment and decipherment. SOLUTION: An external interface 11 to which external equipment is connected, an encipherment processing part 12 enciphering and deciphering applied data, and a control part 15 carrying out various processing according to a program are connected through a data bus B to each other, and a key storing part 14 storing a cryptographic key to be used at encipherment and decipherment to be performed by the encipherment processing part 12 is connected through a read/write control part 13 to a data bus B and the encipherment processing part 12. The read/write limit part 13 is constituted of a writing buffer 13a allowing data (cryptographic key) on the data bus B to pass to the key storage part 14 side and a reading buffer 13b supplying the cryptographic key read from the key storing part 14 to the encipherment processing part 12 side. In this case, the cryptographic key read form the key storing part 14 can be prevented form being outputted to the data bus B. |
