The Enigma machine was a cipher device developed in Germany in the early 1900s. Its fame, besides its technical prowess at the time, was that it was the primary cryptography device used by the Nazi’s during World War II. Seen by them as being unbreakable, the Nazi’s used it to encrypt their most secret messages.
The history of the Enigma, and the dubious errors that led to its being broken, has been documented in scores of books and thousands of articles. In Enigma Myth Deciphered: Codebreakers, Commanders and Politicians (Springer), author Marek Grajek, a Polish cryptologist and historian, details not just the history of the Enigma machine, but the role of the Polish cryptographers played in breaking Enigma.
While the roles of British cryptographers, including Alan Turing, and their American counterparts are well documented, Grajek does an amazing job of providing the history of how Polish cryptographers and mathematicians began to break Enigma as early as 1932. Their role was instrumental for the Americans and the British to fully break Enigma a few years later.
At 500 pages, this is a dense and comprehensive guide to everything directly and indirectly related to Enigma. The book details the history of codebreaking, the mathematical background to cryptography and much more. As a cryptologist and historian, Grajek is uniquely qualified to write on this topic.
While the book is centered around the Enigma machine, similar to Les Misérables, where Victor Hugo devotes about a quarter of the novel to digressions—things not directly related to the plot —Grajek spends a considerable amount of time dealing with parenthetically associated aspects of the machine. He gets into the politics of the times, the interplay between the various countries, and more.
Within the history of cryptography, people such as Martin Hellman, Whitfield Diffie, Ron Rivest, Adi Shamir, and Leonard Adleman (the RSA) are well-known. The world of Polish cryptography is also quite rich. While people such as Marian Rejewski, Jerzy Różycki, and Henryk Zygalski are not well-known outside of their native land, these Polish mathematicians and cryptologists are given their historical due here.
As Grajek details, Rejewski, Różycki, and Zygalski worked at breaking the Enigma ciphers before and during World War II and developed various methods and hardware to break Enigma-based messages. Their work was instrumental in how the Americans and British were ultimately able to break Enigma.
As for Zygalski, the book dedicates a significant amount of time to detailing Zygalski sheets, a cryptologic technique he developed. This technique utilized 26 perforated sheets of paper, mimicking the hardware approach employed by Enigma.
This was an ingenious technique, such that when the sheets were placed over each other and moved in the same sequence that the Enigma would use, it could be used to calculate the order of the rotors on the Enigma machine.
The work performed by Rejewski, Różycki, and Zygalski was significant. In the spirit of open source, they shared what they knew about Enigma with their British and French counterparts, whose progress in breaking Enigma had stalled. Their work enabled the British to break some of the Enigma ciphers. This was a decisive element that led to the ultimate defeat of Germany.
As the title of the book suggests, there are numerous myths surrounding the Enigma. What Grajek does here in this fascinating book is complete the story and demonstrate how Polish cryptologists were instrumental in breaking Enigma. Were it not for them, this review would be written in German.