Method and device for monitoring technically transmitted telephone conversations

摘要

In telephone conversations conducted in a conventional manner, it is not possible to verify the authenticity and the integrity of the received portion of a telephone conversation in a traceable manner. Consequently, it is not possible to monitor whether or not the received portion of the telephone conversation actually originates from the transmitted conversation partner or originates from an unauthorised person (authenticity check). Furthermore, it is not possible to monitor whether the received portion of the telephone conversation has undergone a modification of the original content thereof during transmission (integrity check). According to the invention, such authenticity and integrity checks of telephone conversations may be made possible, by means of a method and device for monitoring technically transmitted conversations, in particular, telephone conversations. Said method comprises providing telephone conversations with so-called digital signatures, which clearly identify each conversation partner. The received telephone conversation may be checked by means of a received digital signature. The additional use of check values for transmitted and received telephone conversations permits the monitoring of the integrity of received telephone conversations.