METHOD FOR AUTHENTICATING COMMUNICATION PARTICIPANTS, SYSTEM FOR APPLICATION OF THE METHOD AND FIRST COMMUNICATION PARTICIPANT AND SECOND COMMUNICATION PARTICIPANT FOR APPLICATION IN THE SYSTEM

摘要

Known methods for authenticating communication participants add a code word to a command signal, which code word is a crytographic function of the command signal and a key value which in its turn is a function of a master key value and a change code word. The master key value has a permanently fixed value, in contrast to the change code word which serves to change the key value. The method according to the invention makes use of a key value which is a function of at least one previous key value, the master key value with the permanently fixed value, which, once it has been discovered or leaked, substantially weakens the encryption, no longer being required.