Patent ID: 7185194

Claim:
A system of distributed group management for indirectly authenticating membership of a user in a group in order to manage security for a client on a client side and a server for executing a remote processing request from the client side under a predetermined authorization assigned for every group, provided with; a group certificate issuing apparatus for issuing a group certificate on the client side based on original group information including the name of the group to which the related user belongs when there is said remote processing request; and a group certificate verification unit for verifying a legitimacy of said group certificate transmitted from the client side in said server, wherein said group certificate issuing apparatus adds an issuance side processed value obtained by encrypting the information of the original group information by a cryptographic function to the original group information and defines this as the group certificate, said group certificate verification unit processes part of the information included in the received group certificate by an identical cryptographic function to obtain a verification side processed value and performs said authentication by confirming that said issuance side processed value and said verification side processed value coincide, said group certificate issuing apparatus includes first secret information assigned to said groups in said original group information and performs the processing by said cryptographic function, said first secret information being held only by said group certificate issuing apparatus, said group certificate verification unit includes second secret information assigned to the groups in part of information included in said received group certificate and performs the processing by said cryptographic function, said second secret information being held only by said group certificate verification unit, said first secret information and said second secret information are identical secret information for identical groups, and said cryptographic function is a hash function.