At present the system supports any static content such as HTML pages, images, and other files such as postscript, pdf, etc. Publius content is encrypted by the publisher and spread over some of the web servers. 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. 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. A particularly interesting feature of SD3 is that it is implemented with a certified evaluator , which produces not only an answer to each security query, but also a proof that the answer follows from the security policy. The proof and the answer are passed through a small and simple proof checker that double checks the result before returning it to the user. This arrangement means that the correctness of the implementation depends only on the correctness of the checker, and not the rest of the evaluator.