METHOD AND APPARATUS FOR RECORDING OF ENCRYPTED DIGITAL DATA

摘要

A method of recording transmitted digital data in which transmitted digital information CW (96) is encrypted (97) using a recording encryption key E(NE) (98) and the resulting encrypted ECM message (99) stored on recording support medium. An equivalent of the recording encryption key E(NE) (100) is further encrypted by a recording transport key RT(A) (102) to form an EMM message (103) stored on the support medium together with the encrypted ECM message (99). In one embodiment, the recording transport key may be generated and managed by a central authorising unit. Alternatively, the recording transport key may be generated and managed within the decoder and recorder configuration of the user, for example, by generating the key at the recorder and communicating a version to the decoder for safekeeping.