| 摘要 |
PROBLEM TO BE SOLVED: To provide an anonymity authentication system reducing a calculation quantity and a communication quantity as compared with a method using zero knowledge certification in the case of revoking a member. SOLUTION: A broadcast type encryption method in which a calculation quantity and a communication quantity are small is used for anonymity authentication. In an authentication verification apparatus 10a for instance, a challenge information generation part 13 generates a random message R, a cryptogram generation part 14 generates a cryptogram C from the message R on the basis of a broadcast type encryption key Kv stored in an encryption key storage part 11 and a cryptogram transmission part 15 transmits the cryptogram C to an authentication request apparatus 30a. In the authentication request apparatus 30a, a cryptogram receiving part 33 receives the cryptogram C, a cryptogram decryption part 34 decrypts the cryptogram C on the basis of a broadcast type cryptogram decryption key Ki stored in a decryption key storage part 31 and a transmission part 35 transmits the decrypted result to the authentication verification apparatus 10a. In the authentication verification apparatus 10a, a verification part 16 verifies whether the decrypted result coincides with the original message R or not and outputs the verified result. COPYRIGHT: (C)2007,JPO&INPIT
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