DATA DISTRIBUTION SYSTEM, SENDING DEVICE, RECEIVING DEVICE, DATA DISTRIBUTION METHOD, SENDING METHOD, RECEIVING METHOD, RECORDING MEDIUM ON WHICH DATA PREPARATION PROGRAM IS RECORDED, AND RECORDING MEDIUM ON WHICH DATA ASSEMBLING PROGRAM IS RECORDED

摘要

PPROBLEM TO BE SOLVED: To provide a data distribution system capable of embedding different pieces of additional information in the same data and encrypting the same data with different cryptographic keys for each receiving device while suppressing an increase in the load of embedding processing and encryption processing of the additional information and in bandwidth needed to distribute data. PSOLUTION: This data distribution system comprises a data dividing means 12 for dividing input data into a plurality of pieces, a divided data replicating means 13 for replicating the divided data, an additional information embedding means 14 for embedding the additional information into the replicated data, an encrypting means 16 for encrypting the data embedded with the additional information, and a sending means 18 for sending the encrypted data by multicast, and further comprises a decoding means 22 for decoding the encrypted data which is received, and an assembling means 24 for assembling a plurality of decoded divided data. PCOPYRIGHT: (C)2003,JPO