DISTRIBUTION SYSTEM, DISTRIBUTION/RECEPTION METHOD, DISTRIBUTION APPARATUS, RECEPTION APPARATUS, DISTRIBUTION PROGRAM AND RECEPTION PROGRAM

PROBLEM TO BE SOLVED: To prevent distribution data from being tampered for the purpose of leakage by disabling which distribution data are addressed to which recipient from being specified. SOLUTION: A recipient number, a private key for each recipient, a specific bit train common for recipients are transmitted/received and stored beforehand between a distribution apparatus and a reception apparatus. The distribution apparatus uses a private key of divided data to encrypt the divided data, uses the private key for each recipient to encrypt and set to a recipient private area a pair of the private key of the divided data and the specific bit train common for recipients, sets and sends out the pair to a multicast packet together with the encrypted divided data. The reception apparatus uses a private key of the recipient's own to decrypt the pair of the private key of the encrypted divided data and the specific bit train included in the recipient private area and, if the decrypted specific bit train matches the stored specific bit train, uses the private key of the divided data to decrypt the divided data. COPYRIGHT: (C)2011,JPO&INPIT