Patent ID: 8204220
Filing Date: 2012-06-19
Classification: H04L,H04N

Abstract:
1. A method of deriving a content key that is shared among a plurality of conditional access (CA) vendors having independent CA systems with each CA system using independent key generation methods, the shared content key used at an encrypter as a control word to encrypt content, the method comprising: receiving a CA Value contribution from each of the plurality of CA vendors at the encrypter, where each CA Value contribution comprises a code word that is independently generated by each of the CA vendors: hashing the CA Values from each of the plurality of CA vendors together using a hashing function to produce an output control word for encryption of the content; at the encrypter using the output control word as a shared content key, wherein the shared content key is used as an encryption key to encrypt content provided to a plurality of receivers that decrypt the content using any of the independent conditional access systems; wherein there are at least two CA Value contributions CAV wherein one of CAV