FIELD: physics; communication.
SUBSTANCE: invention relates to communication systems. In accordance with the invention, a bit sequence known to a network node (MSC/SGSN) and a communication terminal (MS), indicates in the signaling message (Authentication Request) sent to the communication terminal (MS) that the said signaling message (Authentication Request; another message) contains verification value. The verification value received by the communication terminal (MS) is compared with a verification value calculated in the communication terminal (MS), and if the bit sequence has been received in the signaling message (Authentication Request; another message), the communication terminal (MS) defines the signaling message (Authentication Request; another message) as unaltered only if comparison of both verified values gives a positive result.
EFFECT: more efficient identification of changes to the signaling message.
15 cl, 4 dwg
