Copyright protection system and method thereof

摘要

It is characterized to comprise an authentication device 4 having invalid information of a key in relation to cryptology, and for disapproving authentication in case that information of an authentication key is included in the invalid information, which is used for authentication when a first cryptographic key in relation to encrypting is shared between a first encrypting device 3 and a first decryption section 11, and an certificate revocation list updating device 5 for updating contents of the invalid information in the authentication device 4 when receiving information of a key of an object to be invalidated, which is provided together with an input data in relation to a work. <IMAGE>