Publius is a system for anonymous and censorship-resistant publishing on the Net. How it works, straight from their homepage:
Our system consists of publishers who post Publius content to the web, servers who host random-looking content, and retrievers who browse Publius content on the web. At present the
system supports any static content such as HTML pages, images, and other files such as postscript, pdf, etc. Javascript also works. We assume that there is a static, system-wide list of
available servers. Publius content is encrypted by the publisher and spread over some of the web servers. In our current system, the set of servers is static. The publisher takes the key, K
that is used to encrypt the file and splits it into n shares, such that any k of them can reproduce the original K, but k-1 give no hints as to the key. Each server receives the encrypted
Publius content and one of the shares. At this point, the server has no idea what it is hosting -- it simply stores some random looking data. To browse content, a retriever must get the
encrypted Publius content from some server and k of the shares. Mechanisms are in place to detect if the content has been tampered with. The publishing process produces a special URL
that is used to recover the data and the shares. The published content is cryptographically tied to the URL, so that any modification to the content or the URL results in the retriever being
unable to find the information, or a failed verification. In addition to the publishing mechanism, we provide a way for publishers (and nobody else) to update or delete their Publius content.
Publius also provides a way to publish several files at once and to publish mutually hyperlinked material.
The size of individual files is limited to 100 K which is probably supposed to stop people from using it for the distribution of Pamela Anderson videos and Metallica MP3s. Publius was developed by AT&T. The project homepage is at <http://cs1.cs.nyu.edu/waldman/publius/>.