Patent ID: 8879729

Claim:
A method for providing conditional access to at least one of a plurality of media services, each one of the plurality of media services comprising at least one media program, comprising the steps of: transmitting media information encrypted according to a control word (CW) to a receiver station; transmitting entitlement management information (EMI) to the receiver station, the EMI comprising a service bitmap having a plurality of elements, wherein each of the plurality of elements of the service bitmap comprises only one of a first value and a second value wherein the first value of the indexed element of the service bitmap indicates an approved attempted decryption of the control word (CW) by the receiver station and the second value of the indexed element of the service bitmap disapproving the attempted decryption of the control word (CW) by the receiver station; encrypting the control word according to a key derived at least in part from at least a subset of the plurality of elements of the service bitmap, the at least a subset of the plurality of elements including elements having the second value disapproving the attempted decryption of the control word (CW) by the receiver station; and transmitting entitlement control information (ECI) to the receiver station, the entitlement control information including an index to an element of the plurality of elements of the service bitmap and the encrypted control word (CW).