Securing coded, confidential message transmissions

摘要

The transmission takes place over open communication systems between outer stations and exchanges, i.e. signalling, control, and mounting messages in user-user signalling (UUS) of the ISDN D-channel. After installation of a security appts. in the outer station and entry of the ISDN number, the exchange module requests a connection via the security appts. for the initial operation.The operation is set up from the security appts. of the outer station to that of the exchange with a request of a B-channel for data transmission. Then an opposite, individual authenticity check is carried out from the exchange to the outer station with authentic and confidential transmission of a session code. The outer station stores the check as a UUS frame for UUS use.