Contents sale system

摘要

In a contents sale system, original contents data are encrypted into encryption-resultant contents data in response to original playback key data. The original playback key data are encrypted into first encryption-resultant playback key data. The first encryption-resultant playback key data are encrypted into second encryption-resultant playback key data in response to an ID of a sale destination terminal apparatus. The encryption-resultant contents data and the second encryption-resultant playback key data are transmitted to the sale destination terminal apparatus. The sale destination terminal apparatus is enabled to decrypt the second encryption-resultant playback key data into the first encryption-resultant playback key data in response to the ID of the sale destination terminal apparatus. The sale destination terminal apparatus is enabled to decrypt the first encryption-resultant playback key data into the original playback key data. The sale destination terminal apparatus is enabled to decrypt the encryption-resultant contents data into the original contents data in response to the original playback key data.