| 摘要 |
<P>PROBLEM TO BE SOLVED: To ensure the secrecy of a key and the reliability of the update of secret information with a minimum number of times of communication. <P>SOLUTION: A key identifier generation device generates a unique key identifier with the use of random numbers generated by a random number generation device and data that is received from a partner device. A synchronization confirmation device transmits, to the partner device, its own first synchronization confirmation value generated with first secret information and its own second synchronization confirmation value generated with second secret information. It also generates a synchronization determining value with the use of first and second synchronization confirmation values received from the partner as well as with the use of its own first synchronization verification value generated with the first secret information and its own second synchronization verification value generated with the second secret information. A secret information update device generates third secret information from the second secret information and the key identifier, replaces the value of the first secret information with the value of the second secret information, and replaces the value of the second secret information with the value of the third secret information. A key generation device generates a key from the first secret information. <P>COPYRIGHT: (C)2012,JPO&INPIT |
