Defense against man-in-the-middle attack in client-server systems

The deployment of several client-server applications over the Internet and emerging networks requires the establishment of the client´s integrity. This is necessary for the protection of copyright of distributed material and, in general, for protection from loss of “sensitive” (secret) information. Clients are vulnerable to powerful man-in-the-middle attacks through viruses, which are undetectable by conventional anti-virus technology. We describe such powerful viruses and show their ability to lead to compromised clients, that cannot protect copyrighted or “sensitive ” information. We introduce a methodology based on simple hardware devices, called “spies”, which enables servers to establish client integrity, and leads to a successful defense against viruses that use man-in-the-middle attacks