Method and apparatus for encrypting and decrypting communications between a user and a computer over the telephone network, in vocal form in the direction computer to user and in frequency-coded form in the direction user to computer

摘要

The method and apparatus for encrypting and decrypting telephone communications between a user of the telephone network and a central computer when the communications are made in vocal form in the computer-to-user direction and in the form of frequency codes in the user-to-computer direction are characterised by a handler (7) which calculates the encoding key starting from several "passwords" of various origins, so as to apply it to a conversion algorithm allowing encrypting of the signals formed with the aid of the keypad (6) into coded signals transmitted to a generator (10) transmitting with frequency codes. IMAGE