Secured method for setting up a call connection or a transaction between a terminal and an element of a network infrastructure

摘要

To prevent piracy against mobile communications due to the weakening of the A5/2 algorithm, the GMS infrastructure is provided with means to measure the time taken by a telephone to respond to a request ( 121 ) for the use of the A5/1 algorithm. If this time is greater ( 115 ) than the predetermined period, then it is assumed that there is piracy and the call connection is interrupted.