| 摘要 |
PROBLEM TO BE SOLVED: To provide a certificate issuing method in an authentication system capable of precluding leakage of individual information. SOLUTION: This method has a precedure in which a user calculates αk,βk based on an obtained certificate Co so: the signature of a center of issue CI, Po: a uer's public key, Mo: certification matters, the cipher text Eo of an ID: Ecrpte (ej, ID, ro), a code Do: Ecode (ID, ro'), complementary information: (U2o, URo), (V2o, VRo), (c1o, cRo)} and prepares a signature sU with respect to α1||.||αN||β1||.||βN with a secret key So and transmits αk, βk, the signature sU, the certificate Co to the center of issue CI of the certificate and a procedure in which the center of issure CI verfies Co and confirms the effectiveness of the certificate and the signature sU by the public list of a public agency and transmits the subset Ind ki} of an index number to the user and a procedure in which the user calculates Uoki, Voki and transmits Uoki, Voki, rki, xki, gk (p||wki) to the center of issure CI and a procedure in which the center CI calculates αk', βk' and calculates s' by judging αk=αk', βk=βk' and then the user obtains a new certificate C from s'. |
