Patent ID: 7225340
Filing Date: 2007-05-29
Classification: G11B,H04N

Abstract:
1. A method for generating protected digital content, the method comprising: encoding a first digital content with a first encoding parameter to produce a first copy of digital content; encoding the first digital content with a second encoding parameter different from the first encoding parameter to produce a second copy of digital content which is a deteriorated copy of the first digital content; encoding the first digital content with a third encoding parameter different from the first and second encoding parameter to produce a third copy of digital content which is a deteriorated copy of the first digital content; encoding the second copy of digital content with an encrypting key to produce a first encrypted copy of digital content; encrypting twice the third copy of digital content with the encrypting key to produce a second encrypted coy of digital content; and combining the first copy of digital content and the first encrypted copy of digital content and the second encrypted copy of digital content to produce the protected digital content; performing a first decryption of the protected digital content with the encrypting key to obtain the first copy of digital content, wherein the first decryption changes the protected digital content such that the first copy of digital content is no longer available in subsequent copying operations.