Patent ID: 7254838
Filing Date: 2007-08-07
Classification: G06F,H04L

Abstract:
1. A copy protection method for digital media, the method comprising: (a) encrypting an original media data set with a symmetric algorithm corresponding to an original media key; (b) generating an intermediate key by encrypting said original media key with a media identification; (c) encrypting said intermediate key with a public key of a compliant playing device; (d) delivering said encrypted media data set, said encrypted intermediate key, and a media certificate to said playing device, said certificate including a private key identification of said playing device; (e) searching for an actual private key corresponding to said private key identification; (f) decrypting said delivered intermediate key with said actual private key; (g) obtaining said original media key by decrypting said decrypted intermediate key with said media identification; and (h) decrypting said delivered media data set with said obtained media key, wherein said media identification and said public key are separately provided and are independent of each other.