| 摘要 |
<P>PROBLEM TO BE SOLVED: To improve digital copyright management by simplifying the management and operation of a public key certificate to be used for the license distribution of digital contents. <P>SOLUTION: This license distribution server 204 distributes the information of a public key certificate and a secret key as activation information 207 to a client terminal 201 separately from a client module 206. When the public key certificate gets into danger, the license distributing server 204 redistributes only the activation information 207. When a plurality of access control lists in which requested contents and consent conditions corresponding to the client are described exist, the license distributing server 204 generates an individual license by selecting one access control list, and distributes it to the client terminal 201. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
