| 摘要 |
PROBLEM TO BE SOLVED: To improve reliability without influencing a performance in user authentication. SOLUTION: A client 1 transmits a certification start token from a second time onward to a server 2. The server 2 is an authentication information cache generation/update means and updates information in an authentication information cache table 21. That is, a random number R1 is updated to a random number R4 which becomes a species for generating a common key to be used for next authentication confirmation, a random number R2 is updated to a random number R3 to be used for the next authentication confirmation and the common key is updated to a new common key to be used for the next authentication confirmation respectively. The client 1 receives a certification response token from a server 2 by an authentication response token reception means, generates the new common key to be used for the next authentication confirmation on the basis of the R3 and R4 and updates information in an authentication information cache table 11. |
