Common encryption key generating method for e.g. voice over Internet protocol application, involves verifying correspondence between control data displayed on terminal of one user and control data received from another user by latter user

摘要

The method involves determining a common encryption key by each of communication terminals (PA, PB) of users (A, B) from random data (a, b) and initialization data (Ga`, Gb`). Control data (Ca, Cb) are determined from locally calculated initialization data (Ga, Gb) and data (Ga`, Gb`), and are displayed on one user`s terminal. The control data are transmitted to the other user via a voice communication channel (CV). Correspondence between the displayed control data and the control data received from the latter user is verified by the latter user using a validation unit. Independent claims are also included for the following: (1) a computer program executed by a terminal connected to another terminal via a digital link of a communication network (2) a terminal for generating an encryption key common to another terminal.