Information processing apparatus and method

• US 8,595,500 B2
• Filed: 07/23/2010
• Issued: 11/26/2013
• Est. Priority Date: 07/06/2000
• Status: Expired due to Term

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Nakano, Takehiko
• Primary Examiner(s): Cervetti, David Garcia
• Application Number:
  US12/842,312
• Publication Number:
  US 20100313026A1
• Time in Patent Office: 1,222 Days
• Field of Search: 713/171, 713/176, 713/159, 713/189, 713/172, 726/27, 726/31
• US Class Current: 713/171
• CPC Class Codes: H04H 20/76 Wired systems
• CPC Class Codes: H04H 60/23 using cryptography, e.g. encryption, authentication, key distribution
• CPC Class Codes: H04H 60/80 characterised by transmission among terminal devices
• CPC Class Codes: H04L 2209/60 Digital content management, e.g. content distribution
• CPC Class Codes: H04L 9/0822 using key encryption key
• CPC Class Codes: H04L 9/0825 using asymmetric-key encryption or public key infrastructure [PKI], e.g. key signature or public key certificates
• CPC Class Codes: H04L 9/32 including means for verifying the identity or authority of a user of the system or for message authentication, e.g. authorization, entity authentication, data integrity or data verification, non-repudiation, key authentication or verification of credentials
• CPC Class Codes: H04L 9/3252 using DSA or related signature schemes, e.g. elliptic based signatures, ElGamal or Schnorr schemes
• CPC Class Codes: H04L 9/3263 involving certificates, e.g. public key certificate [PKC] or attribute certificate [AC]; Public key infrastructure [PKI] arrangements network architectures or network communication protocols for supporting authentication of entities using certificates in a packet data network H04L63/0823
• CPC Class Codes: H04L 9/3271 using challenge-response

Abstract

In order to limit use of content, when a source receives a request for transmitting content from a sink, the source performs an authentication process. When the authentication is successful, the source transmits to the sink key information necessary for decrypting the encryption applied to the content. The sink can receive the content by receiving the key information and by decrypting the encryption applied to the content by using the key information.

Claims

1. An information processing apparatus, comprising:

a random value transmitting unit that transmits a random value to another information processing apparatus that receives encrypted content;

a signature judging unit that judges whether a signature is valid, the signature being generated by the another information processing apparatus based on the random value and then transmitted from the another information processing apparatus;

a key transmitting unit that transmits key information used for decrypting the encrypted content to the another processing apparatus in response to the signature being valid;

a determining unit that determines an additional value used to update a count of information processing apparatuses that receive the key information based on whether identification information of the another information processing apparatus is registered in a registration list that includes respective identification information of each one of the information processing apparatuses that receive the key information; and

an updating unit that updates the count by adding to it the additional value.

2. An information processing apparatus according to claim 1, wherein the random value is generated using a pseudo-random number generation process.

3. An information processing apparatus according to claim 1, further comprising:

a receiving unit that receives from the another information processing apparatus a digital certificate associated with the another information processing apparatus, and

a control unit that determines whether the digital certificate received from the another information processing apparatus is valid,

wherein the random value transmitting unit transmits the random value to the another information processing apparatus in response to the digital certificate being determined to be valid.

4. An information processing apparatus according to claim 3, wherein the digital certificate includes the identification information of the another information processing apparatus and further key information associated with the another information processing apparatus.

5. An information processing apparatus according to claim 1, wherein the signature is generated by the another information processing apparatus using further key information associated with the another information processing apparatus.

6. An information processing apparatus according to claim 5, wherein the further key information associated with the another information processing apparatus is a private key.

7. An information processing apparatus according to claim 1, wherein the signature judging unit judges whether the signature is valid using further key information associated with the another information processing apparatus.

8. An information processing apparatus according to claim 7, wherein the further key information associated with the another information processing apparatus is a public key.

9. An information processing apparatus according to claim 1, wherein the random value transmitting unit transmits the random value to the another information processing apparatus in response to the count being less than a predefined maximum value.

10. An information processing apparatus according to claim 1, wherein in response to the determining unit determining that the identification information of the another information processing apparatus is not registered in the registration list, the determining unit determines the additional value and the updating unit updates the count by adding to it the additional value, and in response to the determining unit determining that the identification information of the another information processing apparatus is registered in the registration list, the determining unit does not determine the additional value and the updating unit does not update the count.

11. An information processing apparatus according to claim 1, further comprising:

a control section that operates as the random value transmitting unit, the signature judging unit, the key transmitting unit, and the determining unit.

12. An information processing apparatus according to claim 1, further comprising:

a communication interface (I/F), wherein the random value transmitting unit and the key transmitting unit each transmit to the another information processing apparatus via the communication interface, and the signature generated by the another information processing apparatus is received via the communication interface.

13. An information processing apparatus according to claim 1, further comprising:

a content player that plays back content recorded on a medium.

14. An information processing apparatus according to claim 1, further comprising:

an encryption section that encrypts at least one of played back content or received content.

15. An information processing apparatus according to claim 1, further comprising:

a storage section that stores at least one of played back content or received content.

16. An information processing method carried out by an information processing apparatus, the method comprising:

transmitting a random value to another information processing apparatus that receives encrypted content;

judging whether a signature is valid, the signature being generated by the another information processing apparatus based on the random value and then transmitted from the another information processing apparatus;

transmitting key information used for decrypting the encrypted content to the another processing apparatus in response to the signature being valid;

determining an additional value used to update a count of information processing apparatuses that receive the key information based on whether the identification information of the another information processing apparatus is registered in a registration list that includes respective identification information of each one of the information processing apparatuses that receive the key information; and

updating the count by adding to it the additional value.

17. A non-transitory computer-readable medium having recorded thereon computer program instructions for an information processing apparatus to execute an information processing method, the method comprising:

transmitting a random value to another information processing apparatus that receives encrypted content;

judging whether a signature is valid, the signature being generated by the another information processing apparatus based on the random value and then transmitted from the another information processing apparatus;

transmitting key information used for decrypting the encrypted content to the another processing apparatus in response to the signature being valid;

determining an additional value used to update a count of information processing apparatuses that receive the key information based on whether the identification information of the another information processing apparatus is registered in a registration list that includes respective identification information of each one of the information processing apparatuses that receive the key information; and

updating the count by adding to it the additional value.

18. A source device, comprising:

a random value transmitting unit that transmits a random value to at least one of a sink device or a bridge device that receives encrypted content;

a signature judging unit that judges whether a signature is valid, the signature being generated by the at least one of a sink device or a bridge device based on the random value and then transmitted from the at least one of a sink device or a bridge device;

a key transmitting unit that transmits key information used for decrypting the encrypted content to the at least one of a sink device or a bridge device in response to the signature being valid;

a determining unit that determines an additional value used to update a count of devices that receive the key information based on whether identification information of the at least one of a sink device or a bridge device is already registered in a registration list that includes respective identification information of each one of the devices that receive the key information; and

an updating unit that updates the count by adding to it the additional value.

19. A source device according to claim 18, wherein the random value transmitting unit transmits the random value to the at least one of a sink device or a bridge device in response to one or more of (i) the count being less than a predefined maximum value and (ii) the identification information of the at least one of a sink device or a bridge device being already registered in the registration list.

20. A source device according to claim 18, wherein the random value transmitting unit, in response to the count being equal to the predefined maximum value and the identification information of the at least one of a sink device or a bridge device not being already registered in the registration list, does not transmit the random value to the at least one of a sink device or a bridge device.

21. A source device according to claim 18, further comprising an information updating unit that deletes the identification information registered in the registration list and resets to zero the count of devices that receive the key information in response to the decryption key being changed.

22. An information processing method carried out by a source device, the method comprising:

transmitting a random value to at least one of a sink device or a bridge device that receives encrypted content;

judging whether a signature is valid, the signature being generated by the at least one of a sink device or a bridge device based on the random value and then transmitted from the at least one of a sink device or a bridge device;

transmitting key information used for decrypting the encrypted content to the at least one of a sink device or a bridge device in response to the signature being valid;

determining an additional value used to update a count of devices that receive the key information based on whether the identification information of the at least one of a sink device or a bridge device is already registered in a registration list that includes respective identification information of each one of the devices that receive the key information; and

updating the count by adding to it the additional value.

23. An information processing method according to claim 22, wherein the random value is transmitted to the at least one of a sink device or a bridge device in response to one or more of (i) the count being less than a predefined maximum value and (ii) the identification information of the at least one of a sink device or a bridge device being already registered in the registration list.

24. An information processing method according to claim 22, wherein in response to the count being equal to the predefined maximum value and the identification information of the at least one of a sink device or a bridge device not being already registered in the registration list, the random value is not transmitted to the at least one of a sink device or a bridge device.

25. An information processing method according to claim 22, further comprising deleting the identification information registered in the registration list and resetting to zero the count of devices that receive the key information in response to the decryption key being changed.

26. A non-transitory computer-readable medium having recorded thereon computer program instructions for a source device to execute an information processing method, the method comprising:

transmitting a random value to at least one of a sink device or a bridge device that receives encrypted content;

judging whether a signature is valid, the signature being generated by the at least one of a sink device or a bridge device based on the random value and then transmitted from the at least one of a sink device or a bridge device;

transmitting key information used for decrypting the encrypted content to the at least one of a sink device or a bridge device in response to the signature being valid;

determining an additional value used to update a count of devices that receive the key information based on whether the identification information of the at least one of a sink device or a bridge device is already registered in a registration list that includes respective identification information of each one of the devices that receive the key information; and

updating the count by adding to it the additional value.

27. A non-transitory computer-readable medium according to claim 26, wherein the random value is transmitted to the at least one of a sink device or a bridge device in response to one or more of (i) the count being less than a predefined maximum value and (ii) the identification information of the at least one of a sink device or a bridge device being already registered in the registration list.

28. A non-transitory computer-readable medium according to claim 26, wherein in response to the count being equal to the predefined maximum value and the identification information of the at least one of a sink device or a bridge device not being already registered in the registration list, the random value is not transmitted to the at least one of a sink device or a bridge device.

29. A non-transitory computer-readable medium according to claim 26, wherein the information processing method further comprises deleting the identification information registered in the registration list and resetting to zero the count of devices that receive the key information in response to the decryption key being changed.

30. A bridge device, comprising:

a random value transmitting unit that transmits a random value to at least one of a sink device or another bridge device that receives encrypted content;

a signature judging unit that judges whether a signature is valid, the signature being generated by the at least one of a sink device or another bridge device based on the random value and then transmitted from the at least one of a sink device or another bridge device;

a key transmitting unit that transmits key information used for decrypting the encrypted content to the at least one of a sink device or another bridge device in response to the signature being valid;

a determining unit that determines an additional value used to update a count of devices that receive the key information based on whether identification information of the at least one of a sink device or another bridge device is already registered in a registration list that includes respective identification information of each one of the devices that receive the key information; and

an updating unit that updates the count by adding to it the additional value.

31. A bridge device according to claim 30, wherein the random value transmitting unit transmits the random value to the at least one of a sink device or another bridge device in response to one or more of (i) the count being less than a predefined maximum value and (ii) the identification information of the at least one of a sink device or another bridge device being already registered in the registration list.

32. A bridge device according to claim 30, wherein in response to the count being equal to the predefined maximum value and the identification information of the at least one of a sink device or another bridge device not being already registered in the registration list, does not transmit the random value is not transmitted to the at least one of a sink device or another bridge device.

33. A bridge device according to claim 30, further comprising an information updating unit that deletes the identification information registered in the registration list and resets to zero the count of devices that receive the key information in response to the decryption key being changed.

34. A bridge device according to claim 30, wherein the bridge device receives, from a source device, the key information used for decrypting the encrypted content.

35. An information processing method carried out by a bridge device, the method comprising:

transmitting a random value to at least one of a sink device or another bridge device that receives encrypted content;

judging whether a signature is valid, the signature being generated by the at least one of a sink device or another bridge device based on the random value and then transmitted from the at least one of a sink device or another bridge device;

transmitting key information used for decrypting the encrypted content to the at least one of a sink device or another bridge device in response to the signature being valid;

determining an additional value used to update a count of devices that receive the key information based on whether the identification information of the at least one of a sink device or another bridge device is already registered in a registration list that includes respective identification information of each one of the devices that receive the key information; and

updating the count by adding to it the additional value.

36. An information processing method according to claim 35, wherein the random value is transmitted to the at least one of a sink device or another bridge device in response to one or more of (i) the count being less than a predefined maximum value and (ii) the identification information of the at least one of a sink device or another bridge device being already registered in the registration list.

37. An information processing method according to claim 35, wherein in response to the count being equal to the predefined maximum value and the identification information of the at least one of a sink device or another bridge device not being already registered in the registration list, the random value is not transmitted to the at least one of a sink device or another bridge device.

38. An information processing method according to claim 35, further comprising deleting the identification information registered in the registration list and resetting to zero the count of devices that receive the key information in response to the decryption key being changed.

39. An information processing method according to claim 35, wherein the bridge device receives, from a source device, the key information used for decrypting the encrypted content.

40. A non-transitory computer-readable medium having recorded thereon computer program instructions for a bridge device to execute an information processing method, the method comprising:

transmitting a random value to at least one of a sink device or another bridge device that receives encrypted content;

judging whether a signature is valid, the signature being generated by the at least one of a sink device or another bridge device based on the random value and then transmitted from the at least one of a sink device or another bridge device;

transmitting key information used for decrypting the encrypted content to the at least one of a sink device or another bridge device in response to the signature being valid;

determining an additional value used to update a count of devices that receive the key information based on whether the identification information of the at least one of a sink device or another bridge device is already registered in a registration list that includes respective identification information of each one of the devices that receive the key information; and

updating the count by adding to it the additional value.

41. A non-transitory computer-readable medium according to claim 40, wherein the random value is transmitted to the at least one of a sink device or another bridge device in response to one or more of (i) the count being less than a predefined maximum value and (ii) the identification information of the at least one of a sink device or another bridge device being already registered in the registration list.

42. A non-transitory computer-readable medium according to claim 40, wherein in response to the count being equal to the predefined maximum value and the identification information of the at least one of a sink device or another bridge device not being already registered in the registration list, the random value is not transmitted to the at least one of a sink device or another bridge device.

43. A non-transitory computer-readable medium according to claim 40, wherein the information processing method further comprises deleting the identification information registered in the registration list and resetting to zero the count of devices that receive the key information in response to the decryption key being changed.

44. A non-transitory computer-readable medium according to claim 40, wherein the bridge device receives, from a source device, the key information used for decrypting the encrypted content.

45. A system, comprising:

a source device that transmits encrypted content; and

a bridge device that receives the encrypted content and transmits the encrypted content;

the source device, including;

a first random value transmitting unit that transmits a first random value to the bridge device,

a first signature judging unit that judges whether a signature generated by the bridge device is valid, the signature being generated based on the first random value and then transmitted from the bridge device,

a first key transmitting unit that transmits key information used for decrypting the encrypted content to the bridge device in response to the signature generated by the bridge device being valid,

a first determining unit that determines an additional value used to update a count of devices that receive the key information from the source device based on whether identification information of the bridge device is already registered in a first registration list that includes respective identification information of each one of the devices that receive the key information from the source device, and

a first updating unit that updates the count of devices that receive the key information from the source device by adding to it the additional value;

the bridge device, including;

a second random value transmitting unit that transmits a second random value to at least one of a sink device or another bridge device that receives the encrypted content;

a second signature judging unit that judges whether a signature generated by the at least one of a sink device or another bridge device is valid, the signature being generated based on the second random value and then transmitted from the at least one of a sink device or another bridge device;

a second key transmitting unit that transmits the key information used for decrypting the encrypted content to the at least one of a sink device or another bridge device in response to the signature generated by the at least one of a sink device or another bridge device being valid;

a second determining unit that determines a further value used to update a count of devices that receive the key information from the bridge device based on whether identification information of the at least one of a sink device or another bridge device is already registered in a second registration list that includes respective identification information of each one of the devices that receive the key information from the bridge device; and

a second updating unit that updates the count of devices that receive the key information from the bridge device by adding to it the further value.

46. A system according to claim 45, wherein the bridge device further comprises an information updating unit that deletes the identification information registered in the second registration list and resets to zero the count of devices that receive the key information from the bridge device in response to the decryption key being changed by the source device.

47. An information processing apparatus that receives encrypted content, the information processing apparatus comprising:

a random value receiving unit that receives a random value transmitted by another information processing apparatus;

a signature transmitting unit that generates a signature based on the received random value and that transmits the signature to the another information processing apparatus; and

a key receiving unit that receives key information transmitted by the another processing apparatus in response to the another processing apparatus judging that the signature is valid, the key information being used for decrypting the encrypted content

wherein the random value receiving unit receives the random value from the another information processing apparatus in response to the another information processing apparatus determining that a count of information processing apparatuses that receive the key information is less than a predefined maximum value.

48. An information processing apparatus according to claim 47, further comprising:

a digital certificate transmitting unit that transmits a digital certificate associated with the information processing apparatus to the another information processing apparatus,

wherein the random value receiving unit receives the random value from the another information processing apparatus in response to the another information processing apparatus determining that the digital certificate is be valid.

49. An information processing apparatus according to claim 48, wherein the digital certificate includes the identification information of the information processing apparatus and further key information associated with the information processing apparatus.

50. An information processing apparatus according to claim 47, wherein the signature transmitting unit generates the signature using further key information associated with the information processing apparatus.

51. An information processing apparatus according to claim 50, wherein the further key information associated with the information processing apparatus is a private key.

52. An information processing apparatus according to claim 47, wherein the key receiving unit receives the key information in response to the another information processing apparatus judging that the signature is valid using further key information associated with the information processing apparatus.

53. An information processing apparatus according to claim 52, wherein the further key information associated with the information processing apparatus is a public key.

54. An information processing apparatus according to claim 47, further comprising:

a control section that operates as the random value receiving unit, the signature transmitting unit, and the key receiving unit.

55. An information processing apparatus according to claim 47, further comprising:

a communication interface (I/F), wherein the random value receiving unit receives the random value from the another information processing apparatus via the communication interface, and the key transmitting unit transmits the key to the another information processing apparatus via the communication interface.

56. An information processing apparatus according to claim 47, further comprising:

an decryption section that decrypts the encrypted content using the received key information.

57. An information processing apparatus according to claim 47, further comprising:

a storage section that stores at least one of the encrypted content or the decrypted content.

58. A sink device that receives encrypted content, the sink device comprising:

a random value receiving unit that receives a random value transmitted by at least one of a source device or a bridge device;

a signature transmitting unit that generates a signature based on the received random value and that transmits the signature to the at least one of the source device or the bridge device; and

a key receiving unit that receives key information transmitted by the at least one of the source device or the bridge device in response to the at least one of the source device or the bridge device judging that the signature is valid, the key information being used for decrypting the encrypted content

wherein the random value receiving unit receives the random value from the at least one of the source device or the bridge device in response to at least one of the source device or the bridge device determining that a count of such sink devices that receive the key information is less than a predefined maximum value.

59. A sink device according to claim 58, further comprising:

a digital certificate transmitting unit that transmits a digital certificate associated with the sink device to the at least one of the source device or the bridge device,

wherein the random value receiving unit receives the random value from the at least one of the source device or the bridge device in response to the at least one of the source device or the bridge device determining that the digital certificate is be valid.

60. A sink device according to claim 59, wherein the digital certificate includes the identification information of the sink device and further key information associated with the sink device.

61. A sink device according to claim 58, wherein the signature transmitting unit generates the signature using further key information associated with the sink device.

62. A sink device according to claim 61, wherein the further key information associated with the sink device is a private key.

63. A sink device according to claim 58, wherein the key receiving unit receives the key information in response to the at least one of the source device or the bridge device judging that the signature is valid using further key information associated with the sink device.

64. A sink device according to claim 63, wherein the further key information associated with the sink device is a public key.

65. A system, comprising:

a source device that transmits encrypted content; and

a sink device that receives the encrypted content from the source device;

the source device including;

a random value transmitting unit that transmits a random value to the sink device,

a signature judging unit that judges whether a signature generated by the sink device is valid, the signature being generated based on the random value and then transmitted from the sink device,

a key transmitting unit that transmits key information used for decrypting the encrypted content to the sink device in response to the signature generated by the sink device being valid,

a determining unit that determines an additional value used to update a count of devices that receive the key information from the source device based on whether identification information of the sink device is already registered in a sink registration list that includes respective identification information of each one of the devices that receive the key information from the source device, and

an updating unit that updates the count of devices that receive the key information from the source device by adding to it the additional value;

the sink device including;

a random value receiving unit that receives the random value transmitted by the bridge device,

a signature transmitting unit that generates the signature based on the received random value and that transmits the signature to the source device, and

a key receiving unit that receives the key information transmitted by the source device in response to the source device judging that the signature is valid, the key information being used for decrypting the encrypted content.

66. A system, comprising:

a source device that transmits encrypted content;

a bridge device that receives the encrypted content from the bridge device and transmits the encrypted content; and

a sink device that receives the encrypted content from the bridge device;

the source device including;

a first random value transmitting unit that transmits a first random value to the bridge device,

a first signature judging unit that judges whether a first signature generated by the bridge device is valid, the first signature being generated based on the first random value and then transmitted from the bridge device,

a first key transmitting unit that transmits key information used for decrypting the encrypted content to the bridge device in response to the first signature generated by the bridge device being valid,

a first determining unit that determines an additional value used to update a count of devices that receive the key information from the source device based on whether identification information of the bridge device is already registered in a first registration list that includes respective identification information of each one of the devices that receive the key information from the source device, and

a first updating unit that updates the count of devices that receive the key information from the source device by adding to it the additional value;

the bridge device including;

a second random value transmitting unit that transmits a second random value to the sink device;

a second signature judging unit that judges whether a second signature generated by the sink device is valid, the second signature being generated based on the second random value and then transmitted from the sink device;

a second key transmitting unit that transmits the key information used for decrypting the encrypted content to the sink device in response to the second signature generated by the sink device being valid;

a second determining unit that determines a further value used to update a count of devices that receive the key information from the bridge device based on whether identification information of the sink device is already registered in a second registration list that includes respective identification information of each one of the devices that receive the key information from the bridge device; and

a second updating unit that updates the count of devices that receive the key information from the bridge device by adding to it the further value;

the sink device including;

a random value receiving unit that receives the second random value transmitted by the bridge device,

a signature transmitting unit that generates the second signature based on the received second random value and that transmits the signature to the bridge device, and

a key receiving unit that receives the key information transmitted by the bridge device in response to the bridge device judging that the second signature is valid, the key information being used for decrypting the encrypted content.