Patent ID: 7890770

Claim:
A method for deactivating and reactivating security modules intended for accessing control to conditional access data, the security module including a plurality of registers (R 1 , R 2 , R 3 , R n ) containing values, the method comprising: sending, by an operator, at least one management message containing an executable code (RUN-EMM), said executable code being loaded into a memory of the security module, reading the values contained in at least two registers, and modifying the values contained in said at least two registers using a scrambling code, said modification being done in a reversible way such that the initial values contained in said at least two registers are obtained by applying a descrambling code on the modified values and in which a result of the modification depends at least one of the initial values that were read in the registers, wherein the content of the registers after modification of the values renders the module unusable.