Each day Internet is more and more important to us -- It has penetrated almost every aspect of our day to day life, including personal communications, entertainment, shopping, business, etc. We need, therefore, to be able to trust the servers, to be sure they are reliable. Every step taken to make our servers more reliable is a step in the right direction. Every obstacle we put in the intruders' way will be a valuable addition to our servers' overall security.
This work is not unique in its approach. Different programs, such as TCP Wrappers, by Wietse Venema [3] or SMAP, by Marcus Ranum [4], have been written with the idea of wrapping around protocols. None, however, has been written in the spirit presented in this work: To be both a multiple purpose wrapper, protecting different servers and protocols, and to be an informed wrapper, examining each line before it reaches the server.