SERVICE PROVIDING METHOD UTILIZING ATTRIBUTE CERTIFICATE, COMMUNICATION SYSTEM, AUTHENTICATION STATION SERVER, AND SERVICE PROVIDING SERVER

摘要

PROBLEM TO BE SOLVED: To provide an attribute certificate distributing technique capable of directly selecting and displaying only the matters concerning a corresponding attribute certificate. SOLUTION: Each of one or a plurality of attribute certificates 30 for each user and dummy data 32 encrypted by the same encryption key to be paired with the certificates are registered in a directory server 50. A service providing server 40 tries to decode all the dummy data encrypted by the same encryption key to be paired with the attribute certificate for the user by an encryption key received from a user. If there are dummy data which have been decoded by the decoding key received from the user, the server 40 specifies the attribute certificate paired with the dummy data. This makes it possible to find a target attribute certificate without searching the identifier of the attribute certificate (certificate issuer information and serial number information), and eliminates the necessity of delivering the identifier of the attribute certificate by an URL to ensure secure communication. COPYRIGHT: (C)2005,JPO&NCIPI