| 摘要 |
<P>PROBLEM TO BE SOLVED: To generate a key which is safe since its reproducibility is low and hard to be estimated, and to provide a data processor for enciphering data by using the key. <P>SOLUTION: A key generation circuit 605 refers to not only the value of a register at the inside but also the value of a signal at the outside for updating the value of the register at the inside. The signal at the outside referred to by the key generation circuit 605 is set to be, for example a data bus flowing from a main storage 603 to a chip set 602. When the data are enciphered, a CPU (central processing unit) 601 takes out the key from the key generation circuit 605 first, receives data maintained by the main storage 603 for enciphering, and transmits the enciphered data to the main storage 603. The main storage 603 maintains the enciphered data. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
