An anonymous publication system (APS) is a system in which users can anonymously publish and retrieve documents. Furthermore it should be difficult to censor such a system by removing documents or blocking user access. Freenet (freenet.sourceforge.net) and Free Haven (freehaven.net) are some of the more wellknown examples of APSs.

In this lecture I will give an introduction to APSs, including the problems of anonymous communication, content location, and protection of the server operators in an APS. Furthermore I will present my work on Yet Another Anonymous Publication System (YÅPS).