Facts and myths of Enigma: Breaking stereotypes

Abstract

In spite of a relatively large number of publications about breaking Enigma by the Allies before and during the World War II, this subject remains relatively unknown not only to the general public, but also to people professionally involved in cryptological research. For example, the story of Enigma is rarely a part of a modern textbook on cryptology or a modern course on cryptography and network security. There exist multiple reasons for this situation. First, there are still a few unresolved issues, resulting from conflicting reports, the lack of reliable sources, and a long period required for declassifying documents related to any cryptological activity during the World War II. Secondly, the issue is highly political, and there is little consensus in weighing the contribution of all involved countries. Thirdly, many contemporary cryptologists honestly believe that there is little to learn from the analysis of old cryptosystems, because of the tremendous progress in theory and practice of cryptography and a little similarity between old and modern ciphers. In this paper we confront these opinions by presenting a look at the current state of knowledge about cryptological methods and devices used to break Enigma. We introduce all major players involved in these activities, and we make an effort to weigh their original contributions. Finally, we show that the story of Enigma can still provide contemporary cryptographers with many useful lessons regarding the way of organizing and building any large-scale security system. © International Association for Cryptologic Research 2003.