| 摘要 |
A method for transmission and recording of scrambled digital data in which scrambled data is transmitted together with a control word for descrambling of the digital data, the control word Ce itself being encrypted by a first key and transmitted in encrypted form, the scrambled digital data and encrypted control word being received by a decoder 2020 possessing an equivalent of the first key necessary to decrypt the encrypted control word, the decoder being further adapted to pass the digital data in its still scrambled form to a digital recording device 4005 and characterised in that the decrypted control word Ce for descrambling the scrambled data is thereafter re-encrypted by means of a second key C2 stored in a portable support device 4004 adapted to be received by the decoder 2020 and/or digital recording device 4005, the re-encrypted control word being recorded together with the scrambled data on the digital recording medium 4006. When replaying the recording, the control word is decrypted by means of the second key stored on the support means and thereafter used to descramble the recording. <IMAGE> |
