Apparatus and method for hierarchical encryption

1. An apparatus to hierarchically encrypt media data, comprising:

an N-th layer key generator generating an N-th layer key;

an (N+1)-th layer key generator generating an (N+1)-th layer key by applying the N-th layer key to a predetermined function;

an N-th layer data encryptor encrypting N-th layer media data using the N-th layer key; and

an (N+1)-th layer data encryptor encrypting (N+1)-th layer media data using the (N+1)-th layer key.

2. The apparatus of claim 1 , wherein the predetermined function is a one-way function to deduce a value of the function from an input value but not to deduce the input value from the value of the function.

3. The apparatus of claim 1 , wherein the N-th layer media data is the entire media data except key clip data and key frame data, and the (N+1)-th layer media data is the key clip data except the key frame data.

4. The apparatus of claim 1 , wherein the N-th layer data is key clip data of the media data except key frame data of the media data, and the (N+1)-th layer data is the key frame data of the media data.

5. The apparatus of claim 4 , wherein the N-th layer key generator generates the N-th layer key by applying an (N−1)-th layer key to the predetermined function.

6. The apparatus of claim 1 , further comprising:

an N-th layer key buffer temporarily storing the N-th layer key;

an N-th layer key generation commander commanding the N-th layer key generator to generate the N-th layer key according to meta-data when the meta-data is received; and

an N-th layer key supply commander commanding the N-th layer key buffer to supply the N-th layer key to the N-th layer data encryptor according to the meta data when the N-th layer media data is received.

7. The apparatus of claim 1 , further comprising:

an (N+1)-th layer key buffer temporarily storing the (N+1)-th layer key;

an (N+1)-th layer key generation commander commanding the (N+1)-th layer key generator to generate the (N+1)-th layer key according to meta-data when the meta-data is received; and

an (N+1)-th layer key supply commander commanding the (N+1)-th layer key buffer to supply the (N+1)-th layer key to the (N+1)-th layer data encryptor according to the meta data when the (N+1)-th layer media data is received.

8. The apparatus of claim 1 , further comprising:

an N-th layer key encryptor encrypting the N-th layer key.

9. The apparatus of claim 8 , further comprising:

an encrypted N-th layer key transmitter transmitting the encrypted N-th layer key.

10. The apparatus of claim 8 , further comprising:

an encrypted N-th layer key storage block storing the encrypted N-th layer key; and

an encrypted N-th layer key transmitter transmitting the encrypted N-th layer key stored in the encrypted N-th layer key storage block upon a request from a user.

11. The apparatus of claim 1 , further comprising:

an (N+1)-th layer key encryptor encrypting the (N+1)-th layer key.

12. The apparatus of claim 11 , further comprising:

an encrypted (N+1)-th layer key transmitter transmitting the encrypted (N+1)-th layer key.

13. The apparatus of claim 11 , further comprising:

an encrypted (N+1)-th layer key storage block storing the encrypted (N+1)-th layer key; and

an encrypted (N+1)-th layer key transmitter transmitting the encrypted (N+1)-th layer key stored in the encrypted (N+1)-th layer key storage block upon a request from a user.

14. The apparatus of claim 1 , further comprising:

an encrypted N-th layer data transmitter transmitting the encrypted N-th layer media data.

15. The apparatus of claim 1 , further comprising:

an encrypted N-th layer data storage block storing the encrypted N-th layer media data; and

an encrypted N-th layer data transmitter transmitting the encrypted N-th layer media data stored in the encrypted N-th layer data storage block upon a request from a user.

16. The apparatus of claim 1 , further comprising:

an encrypted (N+1)-th layer data transmitter transmitting the encrypted (N+1)-th layer media data.

17. The apparatus of claim 1 , further comprising:

an encrypted (N+1)-th layer data storage block storing the encrypted (N+1)-th layer media data; and

an encrypted (N+1)-th layer data transmitter transmitting the encrypted (N+1)-th layer media data stored in the encrypted (N+1)-th layer data storage block upon a request from a user.

18. An apparatus to hierarchically decrypt media data, comprising:

an N-th layer key generator generating an N-th layer key;

an (N+1)-th layer key generator generating an (N+1)-th layer key by applying the N-th layer key to a predetermined function;

an encrypted N-th layer data decryptor decrypting encrypted N-th layer media data using the N-th layer key; and

an encrypted (N+1)-th layer data decryptor decrypting encrypted (N+1)-th layer media data using the (N+1)-th layer key.

19. The apparatus of claim 18 , wherein the predetermined function is a one-way function by which a value of the function is found from an input value but the input value is not found from the value of the function.

20. The apparatus of claim 18 , wherein the N-th layer media data is the entire media data except key clip data and key frame data, and the (N+1)-th layer media data is the key clip data except the key frame data.

21. The apparatus of claim 20 , wherein the N-th layer key generator receives an N-th layer key and generates the N-th layer key.

22. The apparatus of claim 20 , wherein the N-th layer key generator comprises:

an encrypted N-th layer key receiver receiving the encrypted N-th layer key; and

an encrypted N-th layer key decryptor decrypting the encrypted N-th layer key to generate the N-th layer key.

23. The apparatus of claim 18 , wherein the N-th layer media data is key clip data of the media data except key frame data of the media data, and the (N+1)-th layer media data is the key frame data of the media data.

24. The apparatus of claim 23 , wherein the N-th layer key generator generates the N-th layer key by applying an (N−1)-th layer key to the predetermined function.

25. The apparatus of claim 18 , further comprising:

an N-th layer key buffer temporarily storing the N-th layer key;

an N-th layer key generation commander commanding the N-th layer key generator to generate the N-th layer key according to meta-data when the meta-data is received; and

an N-th layer key supply commander commanding the N-th layer key buffer to supply the N-th layer key to the encrypted N-th layer data decryptor according to the meta data when the encrypted N-th layer media data is received.

26. The apparatus of claim 18 , further comprising:

an (N+1)-th layer key buffer temporarily storing the (N+1)-th layer key;

an (N+1)-th layer key generation commander commanding the (N+1)-th layer key generator to generate the (N+1)-th layer key according to meta-data when the meta-data is received; and

an (N+1)-th layer key supply commander commanding the (N+1)-th layer key buffer to supply the (N+1)-th layer key to the encrypted (N+1)-th layer data decryptor according to the meta data when the encrypted (N+1)-th layer media data is received.

27. An apparatus to hierarchically encrypt and decrypt media data, comprising:

a hierarchical encryption unit generating an N-th layer key, generating an (N+1)-th layer key by applying the generated N-th layer key to a predetermined function, encrypting N-th layer media data using the N-th layer key, and encrypting (N+1)-th layer media data using the generated (N+1)-th layer key; and

a hierarchical decryption unit generating the N-th layer key, generating the (N+1)-th layer key by applying the N-th layer key to the predetermined function, decrypting the encrypted N-th layer media data using the N-th layer key, and decrypting the encrypted (N+1)-th layer media data using the (N+1)-th layer key.

28. The apparatus of claim 27 , wherein the predetermined function is a one-way function by which a value of the function is found from an input value but the input value is not found from the value of the function.

29. The apparatus of claim 27 , wherein the N-th layer media data is the entire media data except key clip data and key frame data, and the (N+1)-th layer media data is the key clip data except the key frame data.

30. The apparatus of claim 27 , wherein the N-th layer media data is key clip data of the media data except key frame data of the media data, and the (N+1)-th layer media data is the key frame data of the media data.

31. The apparatus of claim 27 , wherein the N-th layer key generator generates the N-th layer key by applying an (N−1)-th layer key to the predetermined function.

32. A method of hierarchically encrypting media data, comprising:

generating an N-th layer key;

generating an (N+1)-th layer key by applying the N-th layer key to a predetermined function;

encrypting N-th layer media data using the N-th layer key; and

encrypting (N+1)-th layer media data using the (N+1)-th layer key.

33. The method of claim 32 , wherein the predetermined function is a one-way function by which a value of the function is found from an input value but the input value is not found from the value of the function.

34. The method of claim 33 , wherein the N-th layer media data is the entire media data except key clip data and key frame data, and the (N+1)-th layer media data is the key clip data except the key frame data.

35. The method of claim 32 , wherein the N-th layer media data is key clip data of the media data except key frame data of the media data, and the (N+1)-th layer media data is the key frame data of the media data.

36. The method of claim 35 , wherein the generating of the N-th layer key comprises generating the N-th layer key by applying an (N-1)-th layer key to the predetermined function.

37. The method of claim 32 , further comprising:

temporarily storing the N-th layer key;

commanding that the N-th layer key be generated according to meta-data when the meta-data is received; and

commanding that the stored N-th layer key be supplied to encrypt the N-th layer media data according to the meta data when the N-th layer media data is received.

38. The method of claim 32 , further comprising:

temporarily storing the (N+1)-th layer key;

commanding that the (N+1)-th layer key be generated according to meta-data when the meta-data is received; and

commanding that the stored (N+1)-th layer key be supplied to encrypt the (N+1)-th layer media data according to the meta data when the (N+1)-th layer media data is received.

39. The method of claim 32 , further comprising:

encrypting the N-th layer key.

40. The method of claim 39 , further comprising:

transmitting the encrypted N-th layer key.

41. The method of claim 39 , further comprising:

storing the encrypted N-th layer key; and

transmitting the encrypted and stored N-th layer key upon a request from a user.

42. The method of claim 32 , further comprising:

encrypting the (N+1)-th layer key.

43. The method of claim 42 , further comprising:

transmitting the encrypted (N+1)-th layer key.

44. The method of claim 42 , further comprising:

storing the encrypted (N+1)-th layer key; and

transmitting the encrypted and stored (N+1)-th layer key upon a request from a user.

45. The method of claim 32 , further comprising:

transmitting the encrypted N-th layer media data.

46. The method of claim 32 , further comprising:

storing the encrypted N-th layer media data; and

transmitting the encrypted and stored N-th layer media data at a user's request.

47. The method of claim 32 , further comprising:

transmitting the encrypted (N+1)-th layer media data.

48. The method of claim 32 , further comprising:

storing the encrypted (N+1)-th layer media data; and

transmitting the encrypted and the stored (N+1)-th layer media data upon a request from a user.

49. A method of hierarchically decrypting media data, the method comprising:

generating an N-th layer key;

generating an (N+1)-th layer key by applying the N-th layer key to a predetermined function;

decrypting encrypted N-th layer media data using the N-th layer key; and

decrypting encrypted (N+1)-th layer media data using the (N+1)-th layer key.

50. The method of claim 49 , wherein the predetermined function is a one-way function by which a value of the function is found from an input value but the input value is not found from the value of the function.

51. The method of claim 49 , wherein the N-th layer media data is the entire media data except key clip data and key frame data, and the (N+1)-th layer media data is the key clip data except the key frame data.

52. The method of claim 51 , wherein the generating of the N-th layer key comprises:

receiving an N-th layer key and generating the N-th layer key.

53. The method of claim 51 , Wherein the generating of the N-th layer key comprises:

receiving an encrypted N-th layer key; and

decrypting the encrypted N-th layer key to generate the N-th layer key.

54. The method of claim 49 , wherein the N-th layer media data is key clip data of the media data except key frame data of the media data, and the (N+1)-th layer media data is the key frame data of the media data.

55. The method of claim 54 , wherein the generating of the N-th layer key comprises:

generating the N-th layer key by applying an (N-1)-th layer key to the predetermined function.

56. The method of claim 49 , further comprising:

temporarily storing the N-th layer key;

commanding that the N-th layer key be generated according to meta-data when the meta-data is received; and

commanding that the stored N-th layer key be supplied to the decryption of the encrypted N-th layer media data according to the meta data when the encrypted N-th layer media data is received.

57. The method of claim 49 , further comprising:

temporarily storing the (N+1)-th layer key;

commanding that the (N+1)-th layer key be generated according to meta-data when the meta-data is received; and

commanding that the stored (N+1)-th layer key be supplied to the encryption of the (N+1)-th layer media data according to the meta data when the encrypted (N+1)-th layer media data is received.

58. A method of hierarchically encrypting and decrypting media data, the method comprising:

generating an N-th layer key;

generating an (N+1)-th layer key by applying the generated N-th layer key to a predetermined function;

encrypting N-th layer media data using the N-th layer key, and encrypting (N+1)-th layer media data using the generated (N+1)-th layer key;

generating the N-th layer key;

generating the (N+1)-th layer key by applying the N-th layer key to the predetermined function;

decrypting the encrypted N-th layer media data using the N-th layer key; and

decrypting the encrypted (N+1)-th layer media data using the (N+1)-th layer key.

59. The method of claim 58 , wherein the predetermined function is a one-way function by which a value of the function is found from an input value but the input value is not found from the value of the function.

60. The method of claim 58 , wherein the N-th layer media data is the entire media data except key clip data and key frame data, and the (N+1)-th layer media data is the key clip data except the key frame data.

61. The method of claim 58 , wherein the N-th layer media data is key clip data of the media data except key frame data of the media data, and the (N+1)-th layer media data is the key frame data of the media data.

62. The method of claim 61 , further comprising:

generating the N-th layer key by applying an (N−1)-th layer key to the predetermined function.

63. A computer readable storage medium controlling a computer and comprising a process of:

generating an N-th layer key;

generating an (N+1)-th layer key by applying the N-th layer key to a predetermined function;

encrypting N-th layer media data using the N-th layer key; and

encrypting (N+1)-th layer media data using the (N+1)-th layer key.

64. A computer readable storage medium controlling a computer and comprising a process of hierarchically decrypting media data, comprising:

generating an N-th layer key;

generating an (N+1)-th layer key by applying the N-th layer key to a predetermined function;

decrypting encrypted N-th layer media data using the N-th layer key; and

decrypting encrypted (N+1)-th layer data using the (N+1)-th layer key.

65. A computer readable storage medium controlling a computer and comprising a process of hierarchically encrypting and decrypting media data, comprising:

generating an N-th layer key;

generating an (N+1)-th layer key by applying the generated N-th layer key to a predetermined function;

encrypting N-th layer data using the N-th layer key, and encrypting (N+1)-th media layer data using the generated (N+1)-th layer key;

generating the N-th layer key;

generating the (N+1)-th layer key by applying the N-th layer key to the predetermined function;

decrypting the encrypted N-th layer media data using the N-th layer key; and

decrypting the encrypted (N+1)-th layer media data using the (N+1)-th layer key.