| 摘要 |
<p>A technique to suppress a TRL data amount in a system including a plurality of terminals, a delivery apparatus fetching information (TRL: terminal revocation list) for identifying a terminal to be disabled and delivering data only to the terminals other than those to be disabled, and a control apparatus generating a TRL. Some disabled terminal IDs include a common bit sequence. The control apparatus generates a TRL composed of a data sequence expressed by only the position and values of the common bit sequence and transmits the TRL to a content key delivery apparatus. Each terminal has a terminal ID including a manufacturer type and a serial number and transmits the terminal ID to the content key delivery apparatus to request for content key delivery. The content key delivery apparatus references the TRL to decide whether the terminal ID received from the terminal is a terminal ID to be disabled and unless the terminal ID received is a terminal ID to be disabled, the content key delivery apparatus encrypts and transmits the content key to the terminal.</p> |
