| 摘要 |
PROBLEM TO BE SOLVED: To provide a distribution device for acquiring TRL (terminal revocation list), which is information for identifying a plurality of terminals and terminals to be invalidated and distributing data to only those terminals that are not to be invalidated and technology for suppressing the data volume of TRL, in a system comprising of a management device for generating the TRL. SOLUTION: The management device 110 generates and transmits a TRL formed from data that expresses terminal IDs of all terminals to be invalidated (i.e. terminals whose IDs have a common bit string), by only the value and the position of the common bit string in the IDs, to the content key distribution device 120. Each terminal 130 holds a terminal ID that includes manufacturer type, a serial number and the like, and requests the distribution of a content key by sending the terminal ID with respect to the content key distribution device 120. The content key distribution device 120 refers to the TRL, decides whether the terminal ID transmitted from the terminal is that of an invalidated terminal; and if the terminal ID transmitted is not the terminal ID of the invalidated terminal, encrypts and transmits the content key to the terminal. COPYRIGHT: (C)2007,JPO&INPIT
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