Patent ID: 7620824
Filing Date: 2009-11-17
Classification: H04L

Abstract:
1. A data communicating apparatus for communicating data over a network with members of a group to which the apparatus belongs as another member, said apparatus comprising: a processor; a generating unit configured to generate validity verification data for validating said apparatus; a reporting unit configured to report said validity verification data generated by said generating unit to a management device for managing said group; a holding unit configured to, when said apparatus is validated by said management device based on said validity verification data, hold a group-shared key supplied by said management device solely to said members of said group, along with group identification information for identifying said group and self-identification information for identifying said apparatus; a receiving unit configured to receive encrypted data furnished with said group identification information over said network; a decrypting unit configured to decrypt said encrypted data received by said receiving unit by using said group-shared key corresponding to said group identification information attached to said encrypted data; a verifying unit configured to verify results of the decryption performed by said decrypting unit and to match said self-identification information for identifying said apparatus with recipient identification information attached to said encrypted data; a discarding unit configured to discard said encrypted data and said results of said decryption when the verification of the results of the decryption performed by said verifying unit is negative and when said self-identification information for identifying said apparatus does not match the recipient identification information attached to the encrypted data; a checking unit configured to check to determine whether information which is included in outgoing data to be transmitted and which indicates a source of transmission matches said self-identification information; and a outputting unit configured to output said outgoing data onto said network.