| 摘要 |
PROBLEM TO BE SOLVED: To provide a content transmission and reception system for providing a cryptographic key of content which cannot be easily decrypted.SOLUTION: A content server comprises: a key creation unit for creating a first cryptographic key which is automatically updated at a preset update interval, by request from a user terminal; an embedding unit for embedding the created first cryptographic key to the content; and a transmission unit for transmitting the content to which the first cryptographic key is embedded, with the first cryptographic key which is not embedded, to the user terminal which has requested. The user terminal comprises: a storage unit for storing the received content and the first cryptographic key in a predetermined storage area; an authentication unit for determining whether or not the first cryptographic key embedded in the received content and automatically updated, and the first cryptographic key stored in the predetermined storage area and updated automatically match; and a reproduction unit for reproducing the content when the first cryptographic keys match.SELECTED DRAWING: Figure 1 |
