Access control for digital content

摘要

A recording apparatus operable to apply access control processing to input data content using a set of one or more content keys and to record access-controlled data content on a content storage medium on which a read-only medium identifier is stored comprises: means for encrypting portions of the data content in dependence upon the set of content keys; means for generating content access control data so that decryption of the information content requires access to the read-only medium identifier, the content access control data comprising at least one encrypted version of a respective subset of the set of content keys; and means for recording the encrypted data content and the content access control data on the content storage medium.