A method and apparatus are provided for improving the security of data transmissions between stations and for controlling secured transactions from remote locations in a data-transfer system. The method and apparatus obviate the need for transmitting user-identification information such as personal identification...http://www.google.fr/patents/US4283599?utm_source=gb-gplus-shareBrevet US4283599 - Method and apparatus for securing data transmissions
Method and apparatus for securing data transmissions
