Device and method to render secure the transfer of data between a videotex terminal and a server

摘要

The protection of the transfer of data between a videotex terminal (TVX) and a server (SE) is carried out by means of an additional package (BA) connected to a video adaptor connector (PPI) of the terminal (TVX). In a presession embodiment, the package acts on the switching device (AIG) of the terminal by monitoring any other action on said switching equipment. The switching cabinet and the server conduct dialogue according to a predetermined sequence of operations comprising the definition of a transmitted session key encrypted in accordance with a basic key. Any anomaly occuring during this dialogue aborts the presession mode.