| 摘要 |
PROBLEM TO BE SOLVED: To set a flexible condition such as a validity, its limit on number of times of use and their combination while ensuring the security in the case of conducting authentication. SOLUTION: The user acquires auxiliary information for authentication (t) and control information (L) to generate authentication data denoting a validity of the auxiliary information for authentication in advance. A verification device 100 generates a random number and gives it to a verification device 200 as authentication data. When a time indicated by a clock 81 is included in the validity described in the control information (L), the verification device 200 calculates a value resulting from ciphering authentication data (C) with verification characteristic information and gives the value to the authentication device 100 as certificate information (R). The verification device 100 decodes the authentication data with a public key E corresponding to the authentication characteristic information and when the result is equal to the original authentication data (C), the authentication is successful. |
