UPDATING SITUATION NOTIFYING DEVICE, UPDATING SITUATION ACQUIRING DEVICE AND UPDATING SITUATION COMMUNICATING SYSTEM

摘要

PROBLEM TO BE SOLVED: To notify/acquire an updated situation about information without exchanging updated information, etc.;SOLUTION: An information provider terminal 1 applies to an authentication station 4 for the issuing or lapse of a public key certificate in accordance with the validity/invalidity of information (S3/S27). The station 4 issues a certificate registration request or a certificate lapse list (S7/S31). A certificate effectiveness managing station 3 registers whether or not a certificate is valid in a certificate lapse state database DB1 (S9/33). An information user terminal 2 requests the station 3 for a certificate state (S17/35) in the case of utilizing information with an electronic signature attached thereto from the terminal 1, and the station 3 answers the request (S21/39). The terminal 2 decides the information as valid and uses the information when the certification is valid in the answer and meanwhile, decides the information as invalid and inhibits information use when the certification is lapse (S23/41).;COPYRIGHT: (C)2001,JPO