Data encryption/decryption method, and device

• US 20050069133A1
• Filed: 05/07/2003
• Published: 03/31/2005
• Est. Priority Date: 05/10/2002
• Status: Active Grant

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Shimosato, Tsutomu, Ito, Yujiro
• Granted Patent: US 8,000,476 B2
• Time in Patent Office: Days
• US Class Current: 380/255
• CPC Class Codes: H04L 2209/34 Encoding or coding, e.g. Huffman coding or error correction
• CPC Class Codes: H04L 9/0891 Revocation or update of secret information, e.g. encryption key update or rekeying
• CPC Class Codes: H04N 21/2347 involving video stream encryption
• CPC Class Codes: H04N 21/23602 Multiplexing isochronously with the video sync, e.g. according to bit-parallel or bit-serial interface formats, as SDI
• CPC Class Codes: H04N 21/4405 involving video stream decryption
• CPC Class Codes: H04N 7/1675 Providing digital key or authorisation information for generation or regeneration of the scrambling sequence pseudo-random number generators in general G06F7/58

Abstract

A method of enciphering data which is applicable to cipher-transmission of digital information data, in which the HD-SDI signal DHS is subjected to enciphering process using common key data DEY which is common to encipherment and decipherment to produce enciphered HD-SDI signal DHSE, the common key data DEY are subjected to enciphering process using open key data DOY to produce enciphered common key data DXY, and the enciphered HD-SDI signal DHSE accompanied with the enciphered common key data DXY are send to be transmitted, so that such a fear that the common key data DEY are eavesdropped on the transmission thereof can be effectively reduced.

Claims

1. A method of enciphering data comprising the steps of;

subjecting digital information data to enciphering process using key data for producing enciphered information data,

subjecting the key data to enciphering process using open key data for producing enciphered key data, and

sending the enciphered information data and the enciphered key data.

2. A method of enciphering data according to claim 1, wherein the enciphered information data and the enciphered key data are send to be transmitted through a common data transmission line.

3. A method of enciphering data according to claim 1, wherein the enciphered key data are inserted into the enciphered information data to produce composite enciphered information data to be sent.

4. A method of enciphering data according to claim 1, wherein random number data varying in response to timer output data are produced to be used as said key data.

5. A method of enciphering data according to claim 1, wherein renewed common key data which is renewed in accordance with random number data varying in response to initial common key data and timer output data, are produced to be used as said key data.

6. A method of enciphering data according to claim 1, wherein a random number data sequence lacking reproducibility is constituted with a predetermined number of random number data generated on demand and the random number data contained in the random number data sequence are used as said key data.

7. A method of enciphering data according to claim 1, wherein a random number data sequence lacking reproducibility is constituted with a predetermined number of random number data generated on demand and renewed key data which is renewed in accordance with the random number data contained in the random number data sequence are produced based on initial key data to be used as said key data.

8. A method of enciphering data comprising the steps of;

subjecting digital information data to scrambling process using M-sequence code which has its initial value determined in accordance with M-sequence code initial value data for producing enciphered information data,

subjecting the M-sequence code initial value data to enciphering process using open key data for producing enciphered M-sequence code initial value data, and

sending the enciphered information data and the enciphered M-sequence code initial value data.

9. A method of enciphering data according to claim 8, wherein the enciphered information data and the enciphered M-sequence code initial value data are send to be transmitted through a common data transmission line.

10. A method of enciphering data according to claim 8, wherein the enciphered M-sequence code initial value data are inserted into the enciphered information data to produce composite enciphered information data to be sent.

11. A method of deciphering data comprising the step of;

receiving enciphered information data and enciphered key data,

subjecting the enciphered key data to deciphering process using secret key data for reproducing original key data, and

subjecting the enciphered information data to deciphering process using the reproduced original key data for reproducing original digital information data.

12. A method of deciphering data according to claim 11, wherein the enciphered information data and the enciphered key data are received in the form of composite enciphered information data in which the enciphered key data are inserted into the enciphered information data and the enciphered key data are extracted from the composite enciphered information data.

13. A method of deciphering data comprising the step of;

receiving enciphered information data and enciphered M-sequence code initial value data,

subjecting the enciphered M-sequence code initial value data to deciphering process using secret key data for reproducing original M-sequence code initial value data, and

subjecting the enciphered information data to descrambling process using M-sequence code having its initial value determined in accordance with the reproduced original M-sequence code initial value data for reproducing original digital information data.

14. A method of deciphering data according to claim 13, wherein the enciphered information data and the enciphered M-sequence code initial value data are received in the form of composite enciphered information data in which the enciphered M-sequence code initial value data are inserted into the enciphered information data and the enciphered M-sequence code initial value data are extracted from the composite enciphered information data.

15. A method of enciphering and deciphering data comprising the steps of;

subjecting digital information data to enciphering process using common key data for producing enciphered information data,

subjecting the common key data to enciphering process using open key data for producing enciphered common key data,

sending the enciphered information data and the enciphered common key data,

receiving the enciphered information data and the enciphered common key data,

subjecting the enciphered common key data to deciphering process using secret key data for reproducing the common key data, and

subjecting the enciphered information data to deciphering process using the reproduced common key data for reproducing the digital information data.

16. A method of enciphering and deciphering data comprising the steps of;

subjecting digital information data to scrambling process using M-sequence code having its initial value determined in accordance with M-sequence code initial value data, for producing enciphered information data,

subjecting the M-sequence code initial value data to enciphering process using open key data for producing enciphered M-sequence code initial value data,

sending the enciphered information data and the enciphered M-sequence code initial value data,

receiving the enciphered information data and the enciphered M-sequence code initial value data,

subjecting the enciphered M-sequence code initial value data to deciphering process using secret key data for reproducing the M-sequence code initial value data, and

subjecting the enciphered information data to descrambling process using M-sequence code having its initial value determined in accordance with the reproduced M-sequence code initial value data for reproducing the digital information data.

17. An apparatus for enciphering data comprising;

a key data generating portion for sending key data,

a first enciphering processor for subjecting digital information data to first enciphering process using the key data obtained from the key data generating portion for producing enciphered information data,

a second enciphering processor for subjecting the key data obtained from the key data generating portion to second enciphering process using open key data for producing enciphered key data, and

a data sending portion for sending the enciphered information data and the enciphered key data.

18. An apparatus for enciphering data according to claim 17, wherein the data sending portion is operative to send the enciphered information data and the enciphered key data to be transmitted through a common data transmission line.

19. An apparatus for enciphering data according to claim 17, wherein the data sending portion comprises an enciphered key data inserting portion for inserting the enciphered key data into the enciphered information data for producing composite enciphered information data to be sent.

20. An apparatus for enciphering data according to claim 17, wherein the key data generating portion comprises a timer and a random number data generating portion for producing random number data varying in response to timer output data obtained from the timer, and the random number data obtained from the random number data generating portion are used as said key data.

21. An apparatus for enciphering data according to claim 17, wherein the key data generating portion comprises initial key data generating portion for sending predetermined initial key data, a timer, a random number data generating portion for producing random number data varying in response to timer output data obtained from the timer and a renewed key data generating portion for producing renewed key data which is renewed in accordance with the random number data based on the initial key data obtained from the initial key data generating portion, and the renewed key data obtained from the renewed key data generating portion are used as said key data.

22. An apparatus for enciphering data according to claim 17, wherein the key data generating portion comprises a random number data sequence generating portion for producing a random number data sequence lacking reproducibility and constituted with a predetermined number of random number data generated on demand and the random number data contained in the random number data sequence obtained from the random number data sequence generating portion are used as said key data.

23. An apparatus for enciphering data according to claim 17, wherein the key data generating portion comprises an initial key data generating portion for sending predetermined initial key data, a random number data sequence generating portion for producing a random number data sequence lacking reproducibility and constituted with a predetermined number of random number data generated on demand, and a renewed key data generating portion for producing renewed key data which is renewed in accordance with the random number data contained in the random number data sequence obtained from the random number data sequence generating portion based on the initial key data obtained from the initial key data generating portion, and the renewed key data obtained from the renewed key data generating portion are used as said key data.

24. An apparatus for enciphering data comprising;

an M-sequence code initial value data generating portion for sending M-sequence code initial value data,

a first enciphering processor for subjecting digital information data to scrambling process using M-sequence code having its initial value determined in accordance with the M-sequence code initial value data obtained from the M-sequence code initial value data generating portion for producing enciphered information data,

a second enciphering processor for subjecting the M-sequence code initial value data obtained from the M-sequence code initial value data generating portion to enciphering process using open key data for producing enciphered M-sequence code initial value data, and

a data sending portion for sending the enciphered information data and the enciphered M-sequence code initial value data.

25. An apparatus for enciphering data according to claim 24, wherein the data sending portion is operative to send the enciphered information data and the enciphered M-sequence code initial value data to be transmitted through a common data transmission line.

26. An apparatus for enciphering data according to claim 24, wherein the data sending portion comprises an enciphered M-sequence code initial value data inserting portion for inserting the enciphered M-sequence code initial value data into the enciphered information data for producing composite enciphered information data to be sent.

27. An apparatus for deciphering data comprises;

a data receiving portion for receiving enciphered information data and enciphered key data,

a secret key data generating portion for sending secret key data,

a first deciphering processor for subjecting the enciphered key data to deciphering process using the secret key data obtained from the secret key data generating portion to reproduce original key data, and

a second enciphering portion for subjecting the enciphered information data to deciphering process using the reproduced original key data to reproduce original digital information data.

28. An apparatus for deciphering data according to claim 27, wherein the data receiving portion is operative to receive the enciphered information data and the enciphered key data in the form of composite enciphered information data in which the enciphered key data are inserted into the enciphered information data and to extract the enciphered key data from the composite enciphered information data.

29. An apparatus for deciphering data comprises;

a data receiving portion for receiving enciphered digital information data and enciphered M-sequence code initial value data,

a secret key data generating portion for sending secret key data,

a first deciphering processor for subjecting the enciphered M-sequence code initial value data to descrambling process using the secret key data obtained from the secret key data generating portion for reproducing original M-sequence code initial value data, and

a second deciphering processor for subjecting the enciphered information data to deciphering process using M-sequence code having its initial value determined by the reproduced original M-sequence code initial value data for reproducing original digital information data.

30. An apparatus for deciphering data according to claim 29, wherein the data receiving portion is operative to receive the enciphered information data and the enciphered M-sequence code initial value data in the form of composite enciphered information data in which the enciphered M-sequence code initial value data are inserted into the enciphered information data and to extract the enciphered M-sequence code initial value data from the composite enciphered information data.

31. An apparatus for enciphering and deciphering data comprises;

a common key data generating portion for sending common key data,

a first enciphering processor for subjecting digital information data to first enciphering process using the common key data obtained from the common key data generating portion for producing enciphered information data,

a second enciphering processor for subjecting the common key data obtained from the common key data generating portion to second enciphering process using open key data for producing enciphered common key data,

a data sending portion for sending the enciphered information data and the enciphered common key data,

a data receiving portion for receiving the enciphered information data and the enciphered common key data,

a secret key data generating portion for sending secret key data,

a first deciphering processor for subjecting the enciphered common key data to deciphering process using the secret key data obtained from the secret key data generating portion for reproducing the common key data, and

a second enciphering portion for subjecting the enciphered information data to deciphering process using the reproduced common key data to reproduce the digital information data.

32. An apparatus for enciphering and deciphering data comprises;

an M-sequence code initial value data generating portion for sending M-sequence code initial value data,

a first enciphering processor for subjecting digital information data to scrambling process using M-sequence code having its initial value determined in accordance with the M-sequence code initial value data obtained from the M-sequence code initial value data generating portion for producing enciphered information data,

a second enciphering processor for subjecting the M-sequence code initial value data obtained from the M-sequence code initial value data generating portion to enciphering process using open key data for producing enciphered M-sequence code initial value data,

a data sending portion for sending the enciphered information data and the enciphered M-sequence code initial value data,

a data receiving portion for receiving the enciphered information data and the enciphered M-sequence code initial value data,

a secret key data generating portion for sending secret key data,

a first deciphering processor for subjecting the enciphered M-sequence code initial value data to descrambling process using the secret key data obtained from the secret key data generating portion for reproducing the M-sequence code initial value data, and

a second deciphering processor for subjecting the enciphered information data to deciphering process using M-sequence code having its initial value determined in accordance with the reproduced M-sequence code initial value data for reproducing the digital information data.