Method and apparatus for recording of encrypted digital data
View Patent ↗A method of transmitting and recording digital data scrambled using a control word. The scrambled data is transmitted together with the control word, and the method includes encrypting the control word with a first key. The encrypted control word is transmitted and received, and then decrypted with a decoder that includes an equivalent of the first key. The control word is re-encrypted with a second key stored in a portable support device that is received by the decoder, and the portable support device may be used with any suitable decoder. The re-encrypted control word and the scrambled digital data are recorded on a digital recording medium. An apparatus for transmitting and recording digital data scrambled using a control word. The scrambled data is transmitted together with the control word, and the apparatus includes a transmitter that encrypts the control word with a first key and transmits the encrypted control word. A decoder receives the encrypted control word and decrypts the control word. A portable support device including a second key is received by the decoder, and the decoder uses the second key to re-encrypt the decrypted control word and record the re-encrypted control word and the scrambled digital data on a digital recording medium. The portable support device may be used with any suitable decoder or digital recorder.
1. A method of recording digital data scrambled using a control word encrypted with a first key, the scrambled data being received together with the control word encrypted with the first key, the method comprising:
receiving the encrypted control word and decrypting the control word with a decoder comprising an equivalent of the first key;
re-encrypting the decrypted control word with a second key store in a portable support device adapted to be releasably received by the decoder, the portable support device adapted for use with a plurality of decoders; and
recording the re-encrypted control word and the scrambled digital data on a digital recording medium.
2. The method of claim 1 , wherein the portable support device comprises a smart card adapted to be releasable received by a smart card reader operatively coupled to the decoder.
3. The method of claim 2 , wherein the smart card comprises the equivalent of the first key.
4. The method of claim 2 , wherein the first key is separate from the second key that is stored on the smart card.
5. The method of claim 2 , wherein a single smart card is used to generate the re-encrypted control word for a plurality of recordings.
6. The method of claim 2 , wherein the smart card comprises credit units used to determine how many times the recorded digital data may be replayed.
7. The method of claim 6 , wherein the credit units are decremented after each playing of the recorded digital data.
8. The method of claim 6 , wherein the credit units are associated with a particular segment of the recording so that playing a selected segment of the recording decrements a selected number of credit units associated with that selected segment.
9. The method of claim 6 , wherein the credit units are decremented after the playing of any segment of the recording.
10. The method of claim 1 , wherein the portable support device comprises the digital recording medium, the second key being stored in a circuit disposed proximate the digital recording medium.
11. The method of claim 10 , wherein the circuit is embedded in a housing that encloses the digital recording medium.
12. A method of recording digital data scrambled using a control word encrypted with a first key, the scrambled data being received together with the control word, the method comprising:
receiving the encrypted control word and decrypting the control word with a digital recorder comprising an equivalent of the first key;
re-encrypting the decrypted control word with a second key stored in a portable support device adapted to be releasably received by the digital recorder, the portable support device adapted for use with a plurality of digital recorders; and
recording the re-encrypted control word and the scrambled digital data on a digital recording medium operatively coupled to the digital recorder.
13. The method of claim 12 , wherein the portable support device comprises a smart card adapted to be releasable received by a smart card reader operatively coupled to the digital recorder.
14. The method of claim 13 , wherein the smart card comprises the equivalent of the first key.
15. The method of claim 13 , wherein the first key is separate from the second key that is stored on the smart card.
16. The method of claim 13 , wherein a single smart card is used to generate the re-encrypted control word for a plurality of recordings.
17. The method of claim 13 , wherein the smart card comprises credit units used to determine how many times the recorded digital data may be replayed.
18. The method of claim 17 , wherein the credit units are decremented after each playing of the recorded digital data.
19. The method of claim 17 , wherein the credit units are associated with a particular segment of the recording so that playing a selected segment of the recording decrements a selected number of credit units associated with that selected segment.
20. The method of claim 17 , wherein the credit units are decremented after the playing of any segment of the recording.
21. The method of claim 12 , wherein the portable support device comprises the digital recording medium, the second key being stored in a circuit disposed proximate the digital recording medium.
22. The method of claim 21 , wherein the circuit is embedded in a housing that encloses the digital recording medium.
23. An apparatus for recording digital data scrambled using a control word encrypted with a first key, the scrambled data being received together with the control word encrypted with the first key, the apparatus comprising:
a decoder that receives the encrypted control word and decrypts the control word; and
a portable support device comprising a second key and adapted to be releasably received by the decoder, the decoder adapted to re-encrypt the decrypted control word using the second key and to record the re-encrypted control word and the scrambled digital data on a digital recording medium, the portable support device adapted for use with a plurality of decoders or digital recorders.
24. The apparatus of claim 23 , wherein the decoder comprises a digital recording device adapted to record the encrypted control word and digital data.
25. A smart card adapted to be received in a smart card reader in a decoder, configured to:
receive from the decoder a control word encrypted using a first key;
access an equivalent first key necessary to decrypt the control word,
re-encrypt the decrypted control word using a second key; and
transmit the re-encrypted control word to a digital recording device for recording on a digital recording medium.
26. The smart card of claim 25 , wherein the smart card comprises credit units to determine how many times a recording may be replayed, wherein the credit units are decremented with each partial or complete playing of the recording.