Patent ID: 7970132

Claim:
A controller comprising: digital circuitry configured to receive an encrypted media stream from a provider, wherein the encrypted media stream is encrypted with an encryption key and is configured to be decrypted with a decryption key corresponding to the encryption key, wherein the decryption key is configured to be determined from a selected content key; wherein the digital circuitry is configured to receive with the encrypted media stream an identifier indicative of the selected content key from the provider without receiving with the encrypted media stream either the decryption key or the selected content key; a first non-transitory memory including a plurality of indexes received from the provider prior to the encrypted media stream being received by the digital circuitry, wherein each index respectively corresponds to an identifier, with one of the indexes corresponding to the identifier indicative of the selected content key; and a second non-transitory memory including a plurality of content keys received from the provider prior to the encrypted media stream being received by the digital circuitry, wherein the plurality of content keys correspond to the plurality of indexes, with one of the content keys corresponding to the index which corresponds to the identifier indicative of the selected content key; wherein the digital circuitry is configured to select from the first non-transitory memory the index corresponding to the identifier indicative of the selected content key in response to receiving the encrypted media stream; wherein the digital circuitry is configured to determine from the second non-transitory memory the selected content key using the selected index; wherein the digital circuitry is configured to determine the decryption key from the selected content key and decrypt the encrypted media stream with the decryption key.