METHOD FOR CHANGING AN AUTHENTICATION KEY

摘要

The invention relates to a method for changing an authentication key, said key being associated with a subscriber identification number by the safety module of a communication terminal via a network, the safety module storing a first subscriber authentication key in a first network (12) in association with a first subscriber identification number in the first network, as well as a master key for generating keys specific to a second network (13), wherein the method includes: a step (24) of the safety module receiving a random number provided by the first network; a step (26) of the safety module calculating a second subscriber authentication key in the second network using the master key and the received random number; and a step (32) of storing, in the safety module, the second calculated authentication key in association with a second identification number.