Patent ID: 7684567

Claim:
A method for securing a portable security module for use with a decoding element, the portable security module and the decoding element allowing to descramble scrambled audiovisual information, the method comprising: processing at the portable security module Entitlement Control Messages (ECMs) received at the portable security module to allow the descrambling of the scrambled audiovisual information; analyzing at the portable security module a sequence of ECMs, the sequence of ECMs comprising a new ECM and a previous ECM received at a previous time, the ECMs of the sequence being received at the portable security module at distinct times, the analyzing being performed at the receiving of the new ECM; incrementing an error register upon a determined result of the analyzing, wherein the error register is incremented when the previous ECM and the new ECM do not match; applying a penalty to the portable security module depending on a value of the error register by introducing a dead time at the processing so as to slow down the processing.