Updating of an authentication algorithm in an information system, uses storage of replacement algorithm before first authentication algorithm is inhibited and replacement algorithm activated

摘要

The authentication algorithm operates between a SIM card (CARD) and a server (SERV) which both store a subscriber identifier (IMSI1) associated with an authentication algorithm (Algo1). In a preliminary stage a second inactive authentication algorithm (Algo2) is stored. The first algorithm is then swapped with the second, so that the first algorithm is inhibited and the second activated.