الملخص

Network security has become one of the most important interesting areas for researches. Protecting the network can be done by many mechanisms. Among the most effective one is the network firewall. While the firewall protecting the network from the external intruding, it does upward nothing about the internal intruding. Internal intruding or Inside attacks can lead to a big loosing. One of these attacks is attaching an unauthorized host to the network to get benefits of using the network resources provided by the server (like Internet service) or to leak information into the outside. To solve this problem, this paper suggested that two new programs have to be built under windows operating system in a client server model, one at the client and another at the server. The first supplies an authenticated unique host-ID to each packet destined to leave the network, while the latter verifies these information, allowing the authenticated packet to pass into its destined while dropping and documenting the unauthorized one. This work is considered as a logical extension of the conventional network firewall and can be installed with any of these firewalls. While the conventional firewall is protecting against outside attacks, this work is protecting against one of these inside attacks.