Scramble/descramble method and apparatus for data broadcasting

Abstract

A transmitter for transmitting news data via satellite and which includes an information storage unit for storing news data, an information scramble processing unit for scrambling the news data using a predetermined first key to output once scrambled news data, a data scrambler for scrambling the once scrambled news data using a predetermined second key and outputting twice scrambled news data, a transmitter for broadcasting the twice scrambled news data via a transmitter antenna to a receiver which includes a data descrambler for descrambling the twice scrambled news data using the second key and outputting once descrambled news data, a storage medium for storing the once descrambled news data, an information descramble processing unit for reading the once descrambled data from the recording medium and descrambling the once descrambled news data using the first key to produce fully descrambled news data, and a user terminal for reading the fully descrambled news data.

What is claimed is:  
     
       1. A data transmitting apparatus for transmitting predetermined data, comprising: 
       partial scramble means for scrambling a selected portion of the predetermined data using a first key;  
       entire scramble means for entirely scrambling all of the predetermined data, using a second key, after the selected portion has been scrambled;  
       sending means for transmitting the entirely scrambled predetermined data via a first transmission path; and  
       means for sending the first key in response to a request from a user via a second transmission path.  
     
     
       2. A data transmitting apparatus as claimed in  claim 1  wherein: 
       the predetermined data comprises news data.  
     
     
       3. A data transmitting apparatus for transmitting predetermined data according to  claim 1  wherein the first transmission path comprises circuitry for transmitting the entirely scrambled data via satellite. 
     
     
       4. A data transmitting apparatus as claimed in  claim 3  wherein the second transmission path comprises a data storage medium. 
     
     
       5. A data transmitting apparatus as claimed in  claim 4  wherein the data storage medium comprises an integrated circuit card. 
     
     
       6. A data receiving apparatus for receiving predetermined data via a first transmission path in accordance with a request from a user, the predetermined data having a portion which has been scrambled using a first key and thereafter entirely scrambled using a second key, comprising: 
       entire descramble means for descrambling the entirely scrambled predetermined data using the second key; and  
       partial descramble means for selectively descrambling the portion of the predetermined data using the first key.  
     
     
       7. A data receiving apparatus as claimed in  claim 6 , further comprising: 
       storage means for storing the predetermined data descrambled by the entire descramble means; and  
       wherein the partial descramble means descrambles the portion of the predetermined data stored in the storage means.  
     
     
       8. A data receiving apparatus as claimed in  claim 6  further comprising means for receiving the first key via a second transmission path. 
     
     
       9. A data receiving apparatus as claimed in  claim 8  wherein the second transmission path comprises a data storage medium for storing the first key; and further comprising: 
       a reader for reading the first key from the data storage medium.  
     
     
       10. A data receiving apparatus as claimed in  claim 9  wherein the data storage medium comprises an integrated circuit card. 
     
     
       11. A data receiving apparatus as claimed in  claim 10  further comprising: 
       an identification storage means for storing unique identification data;  
       wherein the data storage medium further comprises means for storing preselected identification data; and  
       wherein the reader includes means for comparing the unique identification data stored in the identification storage means with the identification data stored in the data storage medium and will only read out the first key from the data storage medium when the unique identification data stored in the identification storage means is the same as the identification data stored in the data storage medium.  
     
     
       12. A data transmission system comprising: 
       a transmitter for transmitting news data via satellite wherein the transmitter comprises:  
       an information storage unit for storing news data;  
       an information scramble processing unit for scrambling the news data using a predetermined first key to produce and output once scrambled news data;  
       a data scrambler for scrambling the once scrambled news data using a predetermined second key and outputting twice scrambled news data;  
       a transmitter for broadcasting the twice scrambled news data via a transmitter antenna; and  
       a receiver for receiving the twice scrambled news data transmitted via the satellite, wherein the receiver comprises:  
       a data descrambler for descrambling the twice scrambled news data using the second key and outputting once descrambled news data;  
       a storage medium for storing the once descrambled news data;  
       an information descramble processing unit for reading once descrambled data from the recording medium and descrambling the once descrambled news data using the first key to produce fully descrambled news data; and  
       a user terminal for reading the fully descrambled news data.  
     
     
       13. A method of transmitting news data which includes either or both of text data or graphical data via a broadcast satellite comprising the steps of: 
       storing the news data in a storage medium;  
       retrieving the news data from the storage medium;  
       encoding the news data once, using a feat key, to produce once encoded data;  
       encoding the once encoded data, using a second key, to produce a twice encoded data signal; and  
       broadcasting the twice encoded data signal via the broadcast satellite.  
     
     
       14. A method of receiving news data via a broadcast satellite comprising the steps of: 
       receiving twice encoded data via the broadcast satellite;  
       decoding the twice encoded data using a second key to produce once encoded data;  
       decoding the once encoded data using a first key to produce news data which includes either or both of text data or graphic data; and  
       storing the news data in a storage medium.  
     
     
       15. A news data broadcast system comprising: 
       a transmitter for encoding and transmitting news data via a broadcast satellite and including:  
       a storage medium for storing news data,  
       a first encoder for encoding the news data using primary key data to produce primary encoded news data,  
       a second encoder for encoding the primary encoded news data using secondary key data to produce secondary encoded news data; and  
       a receiver for receiving the secondary encoded news data via the broadcast satellite and including:  
       a first decoder for decoding the secondary encoded news data using the secondary key data to produce the primary decoded news data,  
       a second decoder for decoding the primary decoded news data using the primary key data to produce the news data; and  
       a storage medium for storing the news data.  
     
     
       16. A transmitter for transmitting news data via satellite comprising: 
       an information scramble processing unit for scrambling the news data once using a predetermined first key to produce and output first scrambled news data;  
       a data scrambler for scrambling the once scrambled news data again using a predetermined second key to produce and output twice scrambled news data; and  
       transmitting circuitry for broadcasting the twice scrambled news data via a transmitter antenna.  
     
     
       17. A receiver for receiving news data broadcast via satellite comprising: 
       circuitry for receiving twice scrambled news data broadcast via satellite;  
       a data descrambler for decoding the twice scrambled news data using a predetermined first key and outputting first descrambled data;  
       a storage medium for storing the first descrambled news data;  
       an information descramble processing unit for reading the first descrambled news data from the storage medium and descrambling the first descrambled news data using a second key to produce a fully descrambled news data signal; and  
       a user terminal for viewing the fully descrambled news data.  
     
     
       18. A data transmitting apparatus for transmitting data, comprising: 
       
         a first encryptor for encrypting the data and outputting a first encrypted data;  
       
       
         a second encryptor for encrypting said first encrypted data and outputting a second encrypted data; and  
       
       
         a transmitter for transmitting to a receiver said second encrypted data together with a first key which is used to decrypt the second encrypted data;  
       
       
         wherein said transmitter transmits to said receiver a second key in response to a request from the receiver, the second key being used to decrypt said first encrypted data. 
       
     
     
       19. The data transmitting apparatus as claimed in  claim 18  wherein: 
       
         said second key is transmitted via a transmission path which is different from a transmission path used to transmit said second encrypted data. 
       
     
     
       20. A data transmitting method for transmitting data, comprising the steps of: 
       
         encrypting the data to produce a first encrypted data;  
       
       
         encrypting said first encrypted data to produce a second encrypted data;  
       
       
         transmitting to a receiver said second encrypted data together with a first key which is used to decrypt the second encrypted data; and  
       
       
         transmitting in response to a request from said receiver a second key which is used to decrypt said first encrypted data. 
       
     
     
       21. The data transmitting method as claimed in  claim 20  wherein: 
       
         said second key is transmitted via a transmission path which is different from a transmission path used to transmit said second encrypted data. 
       
     
     
       22. A data receiving apparatus for receiving encrypted data which is transmitted from a transmitter apparatus, the encrypted data is generated by encrypting original data twice by using two different-keys, comprising: 
       
         a receiver for receiving said encrypted data and a first key;  
       
       
         a first decryptor for decrypting said received encrypted data by using said first key;  
       
       
         a requestor for requesting a second key; and  
       
       
         a second decryptor decrypting said decrypted data by using said second key. 
       
     
     
       23. The data receiving apparatus as claimed in  claim 22 , wherein: 
       
         said decrypted data by said first decryptor is stored on a recording medium. 
       
     
     
       24. The data receiving apparatus as claimed in  claim 22 , wherein: 
       
         said requested second key is received via a transmission path which is different from a transmission path used to transmit said encrypted data. 
       
     
     
       25. The data receiving apparatus as claimed in  claim 22 , wherein: 
       
         said requested second key is supplied from a recording medium. 
       
     
     
       26. A method for receiving encrypted data which is transmitted from a transmitter apparatus, the encrypted data being generated by encrypting original data twice by using two different keys, comprising the steps of: 
       
         receiving said encrypted data and a first key;  
       
       
         decrypting said received encrypted data by using said first key;  
       
       
         requesting a second key; and  
       
       
         decrypting said decrypted data by using said second key. 
       
     
     
       27. The method as claimed in  claim 26 , further comprising: 
       
         storing said decrypted data by said first decryptor on a recording medium. 
       
     
     
       28. The method as claimed in  claim 26 , wherein: 
       
         said requested second key is received via a transmission path which is different from a transmission path used to transmit said encrypted data. 
       
     
     
       29. The method as claimed in  claim 26 , wherein: 
       
         said requested second key is supplied from a recording medium. 
       
     
     
       30. A data transmitting and receiving method, comprising the steps of: 
       
         encrypting data to produce a first encrypted data;  
       
       
         encrypting said first encrypted data to produce a second encrypted data;  
       
       
         transmitting to said second encrypted data together with a first key which is used to decrypt the second encrypted data;  
       
       
         receiving said second encrypted data and said first key;  
       
       
         decrypting said received second encrypted data by using said first key;  
       
       
         requesting a second key; and  
       
       
         decrypting said first encrypted data by using said second key. 
       
     
     
       31. The method as claimed in  claim 30 , further comprising: 
       
         storing on a recording medium said first encrypted data which is produced by decrypting second encrypted data. 
       
     
     
       32. The method as claimed in  claim 30 , said requested second key is received via a transmission path which is different from a transmission path used to transmit said second encrypted data. 
     
     
       33. The method as claimed in  claim 30 , wherein: 
       
         said requested second key is supplied from a recording medium. 
       
     
     
       34. The method as claimed in  claim 33 , wherein: 
       
         said recording medium is IC card.