Patent ID: 7426639
Filing Date: 2008-09-16
Classification: G06F,H04L

Abstract:
1. An information processing apparatus, comprising: means for acquiring at least one certificate from each of a plurality of devices belonging to a group, each certificate including identification data allocated to a respective one of the plurality of grouped devices and a public key associated with the respective device; means for storing each of the certificates as a certificate group directly corresponding to the group of devices; means for authenticating the certificates for the group of devices when a content request from one of the plurality of devices is obtained by the acquiring means, including using tags based on leaf identifiers included in each of the certificates to trace associated enabling key blocks to eliminate any revoked certificates; means for encrypting an encryption key using the public keys of each of the authenticated certificates from the plurality of grouped devices to obtain encrypted data composed of a set of encrypted encryption keys associated with each valid device in the group, the encryption key encrypting requested content; and means for providing the encrypted requested content together with the encrypted encryption key to each of the valid devices in the group, wherein the encrypted requested content is configured to be decrypted by each of the devices using a decrypted version of the encrypted encryption key.