The IP Security Protocol, Part 1
Unfortunately, IP packets carry our precious data in a clear form that is easily intercepted by malicious users. Doing this on a common Linux-based PC is actually quite easy, provided that one has access to the network segment over which the desired packets are traveling.
Several different solutions exist that allow us to cope with this problem, each operating at a different level of abstraction. In this article, we will discuss the differences between and purposes of application-level security, socket-level security and network-level security.
The link for this article located at Linux Journal is no longer available.