In 2006 the distributed "M4 Message Breaking Project" under the lead of Stefan Krah aimed at decrypting three ENIGMA M4 messages from the time of World War II. Two of the three messages where decrypted within the first weeks. However, the third message withstood despite all efforts and remained unbroken. Today, the M4 project has been discontinued with the last message still unbroken. The task of this challenge is to break this very last message - after all, a few years have past since the project was discontinued and cryptanalysis and computational power also advanced during this time. Note: The solution was published here: http://www.enigma.hoerenberg.com/. You can't get points for solving it any more, but you can still use it as a good training experience.