This is a summary of an amazing article by the wonderful Bruce Schneier sent in this April’s CryptoGram Newsletter.
The rules for papal elections are steeped in tradition, and were last codified on 22 Feb 1996. The document is well-thought-out, and filled with details. The article elaborates on the election process overview, then on hacking the election process, concluding that the process itself is secure.
A summary of the process follows. The hacking process and the conclusion of Mr. Schneier can be found in here as well.