Method for verifying television receiver sets with access control and corresponding receiver set

A method for verifying a receiver for a television system with access control, wherein the receiver comprises a chip card, wherein a broadcaster transmits corresponding access rights to subscribers having subscribed to subscriptions, the receiver storing the access rights in the chip card, the method comprising:

• the broadcaster performing a plurality of calculations, wherein each of the plurality of calculations is defined by a first parameter corresponding to one of the subscriptions and a second parameter constituted by one of a plurality of characteristics of the receiver;
• the broadcaster then transmitting to the receiver a plurality of results corresponding to the plurality of calculations that is intended for the receiver, the receiver storing the plurality of results in the chip card,
• wherein in order to verify the receiver:
• the broadcaster, after sending the plurality of results, chooses a first parameter and a second parameter specific to the receiver and transmits the chosen parameters to the receiver,
• the receiver performs a subset of the calculations performed by the broadcaster, which is less than said plurality of calculations performed by the broadcaster, using the first and second parameters chosen by the broadcaster
• comparing the result obtained by the receiver and the result previously stored by the receiver, and, in case of difference, altering an operation of the receiver to one selected from a group consisting of a partial halt and a total halt, wherein the partial halt is defined as partially stopping the operation of the receiver and a total halt is defined as stopping operation of the receiver;
• wherein the calculations performed by the broadcaster and the receiver are defined by an encryption algorithm, the first parameter being a subscription key used as an encryption key for the encryption algorithm and the second parameter being a serial number of the receiver.