摘要 |
PROBLEM TO BE SOLVED: To provide a communication method wherein the retrieval of desired information is enabled without needing employment of a server even when information is going to share within a group on a network, and authentication as a member of the group is always enabled among arbitrary members. SOLUTION: A manager or a publisher publishes a participating certificate to which electronic signature is performed with a private key of the group to a general user who newly joins in the group on a network constituted of specified users. On the basis of participating certificates which are published respectively, belonging to the group is authenticated mutually among members of the group, and being legitimate members is confirmed mutually. COPYRIGHT: (C)2004,JPO |