Patent ID: 7885895

Claim:
A method of providing content to a terminal device in a network, the method comprising: storing, in memory, a first content encrypted by a first content key, the first content key encrypted by a first network key, a second content encrypted by a second content key, and the second content key encrypted by the first network key; storing, in a network key storage, the first network key, wherein the first network key is shared with the terminal device; receiving a second network key as an update of the first network key, wherein the second network key is shared with the terminal device; receiving a request for the first content; performing a key update triggered by the request, the key update comprising: decrypting the first content key with the first network key; encrypting the decrypted first content key with the second network key; decrypting the second content key with the first network key; encrypting the decrypted second content key with the second network key; and storing, in the memory, the second content key encrypted by the second network key; and sending the first content encrypted by the first content key and the first content key encrypted by the second network key to the terminal device in response to the request.