Authentication method, encryption method, decryption method, cryptographic system and recording medium

• US 20060155991A1
• Filed: 01/05/2006
• Published: 07/13/2006
• Est. Priority Date: 01/07/2005
• Status: Abandoned Application

• Current Assignee: LG Electronics Company Limited (LG Corporation)
• Original Assignee: LG Electronics Company Limited (LG Corporation)
• Inventors: Yoo, Jea Yong, Seo, Kang Soo, Kim, Kun Suk
• Application Number:
  US11/325,468
• Publication Number:
  US 20060155991A1
• Time in Patent Office: Days
• US Class Current: 713/168
• CPC Class Codes: G11B 20/00086 Circuits for prevention of unauthorised reproduction or copying, e.g. piracy indicating unauthorised use of record carriers in general G11B23/28; scrambling for television signal recording H04N5/913; network architectures or network protocols for network security H04L63/00; cryptographic mechanisms or cryptographic arrangements for secret or secure communication H04L9/00
• CPC Class Codes: G11B 20/0021 involving encryption or decryption of contents recorded on or reproduced from a record carrier
• CPC Class Codes: G11B 2220/2541 Blu-ray discs; Blue laser DVR discs
• CPC Class Codes: H04L 2209/60 Digital content management, e.g. content distribution
• CPC Class Codes: H04L 9/3249 using RSA or related signature schemes, e.g. Rabin scheme
• CPC Class Codes: H04L 9/3268 using certificate validation, registration, distribution or revocation, e.g. certificate revocation list [CRL]
• CPC Class Codes: H04L 9/50 using hash chains, e.g. blockchains or hash trees

Abstract

An authentication method, encryption method, decryption method, cryptographic system and recording medium are disclosed. The present invention includes the steps of decrypting authentication information and a content provider'"'"'s public key stored in a certificate signed by a certificate authority with a public key of the certificate authority to authenticate the content provider using the decrypted authentication information and authenticating the public key of the content provider by checking the decrypted public key of the content provider. And, the present invention provides the encryption method includes the steps of encrypting content data with a secret key, encrypting the secret key with a public key, and transferring the encrypted content data and the encrypted secret key.

Claims

1. An authentication method comprising the steps of:

decrypting authentication information and a content provider'"'"'s public key stored in a certificate signed by a certificate authority with a public key of the certificate authority to authenticate the content provider using the decrypted authentication information; and

authenticating the content provider'"'"'s public key by checking the decrypted public key of the content provider.

2. The authentication method of claim 1, further comprising the step of checking whether the certificate is valid before performing authentication.

3. The authentication method of claim 1, wherein the authentication information and the content provider'"'"'s public key are encrypted using a private key of the certificate authority.

4. The authentication method of claim 1, wherein the certificate is one of a plurality of certificates in a certificate chain.

5. The authentication method of claim 1, wherein the certificate is stored as a file in a recording medium.

6. The authentication method of claim 5, wherein the file exists in a directory storing certificates only within the recording medium.

7. The authentication method of claim 1, wherein the certificate is a certificate downloaded from an outside of a recording medium.

8. The authentication method of claim 1, wherein the certificate follows X.509 of a public key infrastructure (PKI).

9. The authentication method of claim 1, wherein the certificate is a certificate used in authenticating data stored within a recording medium.

10. The authentication method of claim 1, wherein the certificate is a root certificate used in authenticating an application within a recording medium and/or a local storage.

11. The authentication method of claim 1, wherein the certificate is a root certificate used in verifying a signature located at a signature file of a binding unit associated with a recording medium within a local storage.

12. A recording medium comprising:

a data area storing content data; and

an authentication management area storing authentication information,

wherein a certificate generated from encrypting authentication information and a content provider'"'"'s public key is stored in the authentication management area.

13. The recording medium of claim 12, wherein a private key of a certificate authority is used in encrypting the authentication information and the public key.

14. The recording medium of claim 13, wherein the certificate is one of a plurality of certificates in a certificate chain.

15. The recording medium of claim 12, wherein the certificate exists in a directory storing the certificates only within a file structure within the recording medium.

16. The recording medium of claim 12, wherein the certificate is a certificate used for authentication of data within the recording medium.

17. The recording medium of claim 12, wherein the certificate is a root certificate used for authentication of an application within the recording medium.

18. The recording medium of claim 12, wherein the certificate is a root certificate used in verifying a signature located at a signature file of a binding unit associated with the recording.

19. The recording medium of claim 12, wherein the certificate follows X.509 of a public key infrastructure (PKI).

20. An encryption method comprising the steps of:

encrypting content data with a secret key;

encrypting the secret key with a public key; and

transferring the encrypted content data and the encrypted secret key.

21. The encryption method of claim 20, wherein the public key belongs to an optical terminal.

22. The encryption method of claim 20, wherein the public key belongs to a content provider.

23. The encryption method of claim 20, wherein the content data is encrypted by AES algorithm.

24. The encryption method of claim 20, wherein the content data is encrypted by DES algorithm.

25. The encryption method of claim 20, wherein the secret key is encrypted by RSA cryptographic algorithm.

26. The encryption method of claim 20, wherein the public key is distributed by a handshake process between a content provider and an optical player.

27. The encryption method of claim 20, wherein the secret key comprises a session key.

28. The encryption method of claim 27, wherein the session key is generated by using random data.

29. A decryption method comprising the steps of:

receiving an encrypted secret key and encrypted content data;

decrypting the encrypted secret key; and

decrypting the encrypted content data using the decrypted secret key.

30. The decryption method of claim 29, wherein the encrypted secret key is decrypted using a private key of an optical player.

31. The decryption method of claim 29, wherein the encrypted secret key is decrypted using a private key of a content provider.

32. The decryption method of claim 29, wherein the encrypted secret key is decrypted by RSA cryptographic algorithm.

33. The decryption method of claim 29, wherein the encrypted content data is decrypted by AES algorithm.

34. The decryption method of claim 29, wherein the encrypted content data is decrypted by DES algorithm.

35. The decryption method of claim 29, wherein the secret key comprises a session key.

36. The decryption method of claim 35, wherein the session key is generated through random data.

37. A cryptographic system comprising:

an encryption system encrypting content data with a secret key, the encryption system encrypting the secret key with a public key, the encryption system transferring the encrypted content data and the encrypted secret key; and

a decryption system receiving the encrypted secret key and the encrypted content data, the decryption system decrypting the encrypted secret key, the decryption system decrypting the encrypted content data using the decrypted secret key.