| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide configuration for effectively preventing illegal processing in content use accompanied by data transfer between different devices. <P>SOLUTION: An acknowledgement device group certificate is used to judge the validity of an open key certificate applied to mutual authentication between devices, and a device number data certificate (AIC) in which the number of registered devices, the number of ineffective (revoke) devices, etc., is set as registration data is applied to new/old decision making of the acknowledgement device group certificate; and it is decided whether the acknowledgement device group certificate is the latest based upon registration of registration information or the change state of the number of ineffective devices by regarding a certificate which is large in number of registered devices or ineffective devices as a new certificate and so on, and the new acknowledgement device group certificate is applied to decide the validity of the open key certificate of a device, thereby performing mutual authentication. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
