Patent ID: 8737990

Claim:
A method for conditional access to a digital data stream encrypted with at least one control word and broadcast via a plurality of transmitters in a broadcast network to at least one mobile device in communication with a transmitter among the plurality of transmitters, said method comprising: receiving a control message stream by the mobile device, the control message stream comprising control words and access conditions, the access conditions including at least one location identifier; receiving a current location identifier by the mobile device, the current location identifier being transmitted by and identifying the transmitter; performing by the mobile device a comparison of the current location identifier with the location identifier contained in the access conditions; and authorizing or blocking the access to said data stream by the mobile device depending on the result of said comparison; wherein the control word comprises a key for decrypting the encrypted digital data stream, the control word being received in encrypted form; and wherein the access conditions further comprise at least one entitlement description related to the broadcasted content and wherein the authorization or blocking of the access further depends on the presence of the at least one entitlement description.