Recording of scrambled digital data

Abstract

A system for transmitting and recording digital data is included. Further, a system for transmitting transmit scrambled audio data that is to be recorded on a mini disc reader is included. A system for transmission and recording of digital data includes transmission means adapted to prepare and transmit scrambled digital data together with at least one encrypted control word and a digital recording device adapted to receive and record the scrambled digital data and encrypted control word on a digital support. The digital recording device further includes an access control means adapted to decrypt the control word and thereafter descramble the digital data during playback.

1. A system for transmission and recording of digital data, comprising:
 a transmission means adapted to:
 prepare and transmit at least one  a first control word encrypted by a first key together with a first title of digital data scrambled by that  the first control word;  
 separately prepare and transmit a first message comprising the first key and first credit information, wherein the first message is encrypted by a second key;  
   prepare and transmit a second control word encrypted by a third key together with a second title of digital data scrambled by the second control word; and    
   separately prepare and transmit a second message comprising the third key and second credit information, wherein the second message is encrypted by a fourth key;   
 
 a digital recording device comprising an access control unit and adapted to:
 receive the first and second transmitted messages, encrypted by the second and fourth keys, comprising the first key and the first credit information as well as the third key and the second credit information; 
 receive and record, on a digital support, the transmitted scrambled first title of digital data together with the encrypted control word, the digital recording device including an  and the transmitted scrambled second title of digital data together with the second encrypted control word;  
 
   the  access control unit comprising a credit unit and adapted to: use the second key to decrypt the first message and obtain the first key;   decrypt the first encrypted control word and  using the decrypted first key;   thereafter descramble the scrambled first title of digital data during playback, wherein said access control module comprises a ;   use the fourth key to decrypt the second message and obtain the third key;      decrypt the second encrypted control word using the decrypted third key; and        thereafter descramble the scrambled second title of digital data during playback; and      
   the  credit unit adapted to: decrypt the first encrypted message to obtain the first key and the first credit information;      decrypt the second encrypted message to obtain the third key and the second credit information; and        use the first and second credit information to  control a total number of recordings madecapable of being recorded by the digital recording device, wherein recording the first title of digital data, using the first credit information, results in decrementing the total number of recordings, and wherein recording the second title of digital data, using the second credit information, results in further decrementing the same total number of recordings held by the recording device.    
 
     
     
       2. A  The system as claimed in  claim 1  in which , wherein the access control unit is incorporated in a discrete module insertable in the digital recording device to permit decryption and descrambling of the  each recorded title of digital data upon playback. 
     
     
       3. A  The system as claimed in  claim 1 , further comprising a separate receiver/decoder adapted to receive the transmitted first and second titles of digital data and the first and second encrypted code word  control words and to communicate this information  the first and second titles of digital data and the first and second encrypted control words to the digital recording device for subsequent recordal. 
     
     
       4. A  The system as claimed in  claim 1  in which , wherein the transmission means is adapted to repetitively transmit the scrambled first and second titles of digital data and the first and second encrypted code word  control words. 
     
     
       5. A  The system as claimed in  claim 1  in which , wherein the first control word for the data  is encrypted by a  the first key associated with the identity of the first title of digital data being transmitted, and wherein the second control word is encrypted by the third key associated with the identity of the second title of digital data being transmitted. 
     
     
       6. A  The system as claimed in  claim 5  in which , wherein the first key is encrypted by a  the second key and the third key is encrypted by the fourth key before communication to the access control unit. 
     
     
       7. A  The system as claimed in  claim 5  further comprising a key encryption apparatus adapted to encrypt the  an equivalent of the first key by a  the second key and the third key by the fourth key before communication to the digital recording device, the access control unit possessing an equivalent of the second key and the fourth key so as to permit the decryption of the first key and the third key and, thereafter, the decryption of the first and second control word and subsequent descrambling of the transmitted first and second titles of digital data. 
     
     
       8. A  The system as claimed in  claim 7 , further comprising a receiver/decoder unit adapted to request a  the equivalent of the first key and the third key from the key encryption apparatus, the key encryption apparatus thereafter communicating the encrypted equivalent first key and third key to the receiver/decoder for subsequent communication to the digital recording device and access control module. 
     
     
       9. A  The system as claimed in  claim 1 , wherein the access control module comprising a  credit unit for controlling the number of times a recording  is further configured to control the number of times the first and second titles of digital data, after being recorded, are played. 
     
     
       10. A  The system as claimed in  claim 1  in which , wherein the same  first key is used to encrypt the  a plurality of first control word or  words associated with a plurality of sets of  first titles of digital data, and wherein the third key is used to encrypt a plurality of second control words associated with a plurality of second titles of digital data. 
     
     
       11. A  The system as claimed in  claim 1  in which , wherein the first  second key is repetitively transmitted by the transmission means in a third message encrypted by a second  fifth key, and wherein the fourth key is repetitively transmitted by the transmission means in a fourth message encrypted by a sixth key. 
     
     
       12. A system as claimed in  claim 11 , in which the message sent by the transmission means containing the encrypted first key also contains credit information intended for a credit unit within the access control module. 
     
     
       13. A  The system as claimed in  claim 1  in which , wherein the transmission means responds to a real-time request to transmit the scrambled first and second titles of digital data and encrypted first and second control word  words. 
     
     
       14. A  The system as claimed in  claim 13  in which , wherein the first and second control word is  words are directly encrypted by a  the first and third key associated with the identity of the access control unit, the access control unit possessing an equivalent of the first and third key to permit the decryption of the first and second control word  words and subsequent descrambling of the first and second titles of digital data. 
     
     
       15. A  The system as claimed in  claim 1  in which , wherein the transmission means is adapted to transmit audio data. 
     
     
       16. A  The system as claimed in  claim 15  in which , wherein the digital recording device comprises a mini disc recorder adapted to include access control means. 
     
     
       17. A recording device for use in the system as claimed in  claim 1 , adapted to record scrambled data and an associated encrypted control word and comprising an access control means adapted to decrypt the recorded control word and descramble data upon playback. 
     
     
       18. A  The system for transmission and recording of digital data  as claimed in  claim 1 , wherein said  the encrypted first and second control word is  words are transmitted within entitlement control messages and wherein said  the access control module controls the total number of recordings made by the digital recording device as a function of price information included in said  the entitlement control messages. 
     
     
       19. A method of transmission and recordal of digital data, comprising:
 preparing and transmitting a scrambled first title of digital data together with at least one  a first control word encrypted by a first key using a transmission means;  
 separately preparing and transmitting a first message comprising the first key and first credit information, wherein the first message is encrypted by a second key using the transmission means, wherein the second key also decrypts the first key and wherein the first credit information is associated with the scrambled first title of digital data;  
   preparing and transmitting a scrambled second title of digital data together with a second control word encrypted by a third key using a transmission means;    
   separately preparing and transmitting a second message comprising the third key and second credit information, wherein the second message is encrypted by a fourth key using the transmission means, wherein the fourth key also decrypts the third key and wherein the second credit information is associated with the scrambled second title of digital data;   
 recording the transmitted scrambled first title of digital data and encrypted first control word and the transmitted scrambled second title of digital data and encrypted second control word on a digital support using a digital recording device, the digital recording device comprising an access control means, wherein the access control means comprises a credit unit;  
 after using the second key to decrypt the first message and obtain the first key, decrypting the encrypted first control word and thereafter descrambledescrambling the scrambled first title of digital data during playback using the access control means, wherein said access control module comprises a credit unit for controlling a number of recordings made by the digital recording deviceand the decrypted first control word;  
 after using the fourth key to decrypt the second message and obtain the third key, decrypting the encrypted second control word and thereafter descrambling the scrambled second title of digital data during playback using the access control means and the decrypted second control word; and  
   decrypting the encrypted first and second messages and thereafter descrambling the first and second credit information using the credit unit, wherein the credit unit, using the first and second credit information, controls a total number of recordings capable of being recorded by the digital recording device, wherein recording the scrambled first title of digital data, using the first credit information, results in decrementing the total number of recordings, and wherein recording the scrambled second title of digital data, using the second credit information, results in further decrementing the same total number of recordings held by the recording device.    
 
     
     
       20. A method of recordal and playback of digital data, comprising:
   receiving a scrambled first title of digital data and a first control word encrypted by a first key for descrambling the received scrambled first title of digital data;        separately receiving a first message comprising the first key and first credit information encrypted by a second key, wherein the second key is used to decrypt the first message and obtain the first key, and wherein the first credit information is associated with the scrambled first title of digital data;        receiving a scrambled second title of digital data and a second control word encrypted by a third key for descrambling the received scrambled second title of digital data;        separately receiving a second message comprising the third key and second credit information encrypted by a fourth key, wherein the fourth key is used to decrypt the second message and obtain the third key, and wherein the second credit information is associated with the scrambled second title of digital data;        determining whether at least one credit exists for recording the scrambled first title of digital data and the first control word, wherein a credit unit uses the second key to decrypt the first message and the first credit information and thereafter, using the first credit information to determine that the at least one credit exists;        determining whether the at least one credit exists for recording the scrambled second title of digital data and the second control word, wherein the credit unit uses the fourth key to decrypt the second message and the second first credit information and thereafter, using the second credit information to determine that the at least one credit exists;        only recording the scrambled first title of digital data and the first control word, as well as the scrambled second title of digital data and the second control word, on a digital support using a digital recording device, wherein the digital recording device comprises an access control means, and wherein the access control means comprises the credit unit, wherein the credit unit is configured to use the first and second credit information to control a total number of recordings capable of being recorded by the digital recording device;        decrementing the total number of recordings, using the first credit information, when recording the scrambled first title of digital data; and        further decrementing the same total number of recordings held by the recording device, using the second credit information, when recording the scrambled second title of digital data.     
     
     
       21. The method of  claim 20 , further comprising:
   decrypting the encrypted first and second control words;        descrambling the scrambled first and second titles of digital data using the access control means and the decrypted first and second control words; and        playing back the descrambled first and second titles of digital data.     
     
     
       22. A digital recording device, comprising:
   means for receiving a scrambled first title of digital data and a first control word encrypted by a first key for descrambling the received scrambled first title of digital data;        means for receiving a first message comprising the first key and first credit information encrypted by a second key, wherein the second key is used to decrypt the first message and obtain the first key, and wherein the first credit information is associated with the scrambled first title of digital data;        means for receiving a scrambled second title of digital data and a second control word encrypted by a third key for descrambling the received scrambled second title of digital data;        means for receiving a second message comprising the third key and second credit information encrypted by a fourth key, wherein the fourth key is used to decrypt the second message and obtain the third key, and wherein the second credit information is associated with the scrambled second title of digital data;        means for determining whether at least one credit exists for recording the received scrambled first title of digital data and the first control word, wherein a credit unit uses the second key to decrypt the first message and the first credit information and thereafter, using the first credit information to determine that the at least one credit exists;        means for determining whether the at least one credit exists for recording the received scrambled second title of digital data and the second control word, wherein a credit unit uses the fourth key to decrypt the second message and the second credit information and thereafter, using the second credit information to determine that the at least one credit exists;        means for recording the scrambled first title of digital data and the first control word, as well as the scrambled second title of digital data and the second control word, on a digital support using a digital recording device, the digital recording device comprising an access control means, which comprises a credit unit configured to use the first and second credit information to control a total number of recordings capable of being recorded by the digital recording device;        means for decrementing the credit unit, using the first credit information, when recording the scrambled first title of digital data; and        means for further decrementing the same credit unit, using the second credit information, when recording the scrambled second title of digital data.     
     
     
       23. The digital recording device of  claim 22 , further comprising:
   means for decrypting the encrypted first and second control words;        means for descrambling the scrambled first and second titles of digital data using the access control means and the decrypted first and second control words; and        means for playing back the descrambled first and second titles of digital data.