Patent ID: 7099479
Filing Date: 2006-08-29
Classification: G06F,G06Q,G10K,H04L

Abstract:
1. An information distribution system for distributing predetermined content data from an information sending device to an information receiving device, said information sending device comprises: first storing means for storing content data that is prohibited from being played by an information receiving device that does not include a content key; second storing means for storing content data that is permitted to be played by an information receiving device that does not include the content key; sending end controlling means for encrypting said content data with a content key, and encrypting the content key with an individual key specific to said information sending device; and sending means for sending an encrypted individual key by encrypting said individual key with one of a plurality of distribution keys, each distribution key corresponding to a predetermined time period, to said information receiving device together with said content data encrypted with said content key and a content key encrypted with said individual key, and said information receiving device comprises: receiving means for receiving said content data encrypted with said content key and said content key encrypted with said individual key together with said encrypted individual key; and receiving end controlling means for decrypting said individual key with one of said plurality of distribution keys, decrypting said content key with the decrypted individual key, and decrypting said content data with the decrypted content key; and allowing decryption of said individual key within the predetermined time period associated with said distribution key, independent of a connection during said predetermined time period associated with said distribution key.