| 摘要 |
PROBLEM TO BE SOLVED: To prevent wiretapping/interpolation of contents by a 3rd party. SOLUTION: A contents body key encrypts contents body (3), hash function processing is applied to a header of the contents to obtain a fixed length character string (4), the contents body key is primarily encrypted by using the fixed length character string (5), the contents body encryption key primarily encrypted is secondarily encrypted by using an encryption key of a distributor (6), and the header, the contents body encryption key that is secondarily encrypted, and the encrypted contents body are stored as contents (7). In the case of transfer, the header and the encrypted contents body are sent to a receiver side device, the contents body encryption key that is secondarily encrypted are decoded, the contents body encryption key primarily encrypted is encrypted by using the encryption key of the receiver side device and the result is sent to the receiver side device. |
