Battle of Wits: The Complete Story of Codebreaking in World War II

I have for many years wondered exactly how the supposedly unbreakable German Enigma machine and the Japanese diplomatic and Naval codes were broken. Stephen Budiansky does a great job at explaining how this was done. This was no easy task, requiring the ability to explain complex mathematical and mechanical concepts in a political and military context. Budiansky is uniquely suited to this task and I for one am grateful for his successful effort. He has a master's degree in applied mathematics, along with work in military studies as a Congressional Fellow. To this one must add that he is a good writer, as attested to by the fact that he is a correspondent for The Atlantic, The New York Times and The Economist among other prestigious publications. This is no dry academic text, but is a story of great excitement, of great internal rivalries and intrigues. It is also fortunately much more, as it also goes into detail about the design and operation of the code machines and ciphers, as well as the novel approaches that were used to overcome them. It goes into considerable detail about these approaches, without becoming overly pedantic. This book covers the Japanese Diplomatic and Naval codes as well as the German Enigma machine. As such, it covers both code machines and ciphers, with a very good discussion of the history of both and the distinction between them. This book is more than a dry discussion of mathematics, but also delves into the personalities of the people involved and the internal rivalries between the US Army and Navy and between the civilian and military branches of the governments involved. It touches on espionage and the application of the knowledge of what was learned from the code breaking. I was aware of the general outlines of what was done, of Bletchley Park and the American equivalents and of the importance of the early work of Polish code breakers. What I was not aware of was exactly how this was done. The Germans were confident that even if the allies got hold of a code machine they could not unscramble a message that was coded with what was a virtually unlimited number of possible combinations. I now have a better idea of how this was done and if you read this book so will you. I learned of the importance of a spy in Germany who early on provided a few messages and some code setting that were of great initial help, how German regularity in the form of the messages and the laziness of some operators in reusing the same text were of great importance, of the struggles to overcome the continual changes in the machines and upgrading of the codes. Most of all, I learned of the creativity and persistence of the human mind. My only criticism, and it is a minor one, is that very little space is given to the German and Japanese efforts (many of them successful) in deciphering allied codes. I hope that this will be the subject of a future book of Budiansky's.

Very thoroughly researched, with lots of new and interesting details. Especially clear explanations of how it all worked. This is not "cryptology for drooling idiots," but with a little attention you can follow the details without knowing anything about group theory. I really liked the material about the development of mechanical methods for sorting and correlating -- poorly covered in most accounts.Sticks to documented facts and steers clear of speculation and hearsay, which may be part of why the book seems slightly light on the Pacific side. But if you like your history factual, clear, and well-written, this is an excellent book.It's no accident that it sells well in Virginia and Maryland!

Unquestionably the finest general history of codebreaking in the Second World War. This comprehensive, well-researched and well-balanced treatment is particularly valuable for its account of the US contribution to the codebreaking war. Everyone interested in cryptanalysis or the history of the Second World War should read this book.

This book is well-written in a clear, flowing and lucid style. Lots of details and human interest liven up a subject that is always on the edge of putting some readers to sleep. This book surveys code-breaking in both the European and Pacific theaters of war and even-handedly deals with the contributions of both the Brits and the Yanks (all too few books on this topic do so). The author wisely puts the most arcane bits of math in appendices.Very well done and hightly recommended to both those who have never read a book on this subject and those who have read several.

This book deserves more than five stars, and the massive British and American government information releases that made it possible also deserve credit for making the book possible.This book pays the reader the compliment of assuming both intelligence and sincere interest in the subject. Although much of the book is a repeat of what has been written before, the book also contains much new information (especially about breaking the Japanese codes) and important insights. As the most complete examination of the code side of World War II, the book is essential reading for anyone who is interested in that conflict.Although this book is about World War II, it contains much interesting material about earlier code-breaking, especially during World War I and the disarmament conference in the 1920s. Basically, codes and codebreaking were in a transition period during the 1930s and 1940s between the primitive historical codes and the modern encryption techniques. The weakness of this transition period was that computer-like devices could use brute force calculations to spot patterns that the code designers were unaware of.Clues came from many places. For example, "eins" showed up very frequently in German communications, so by looking for four word groups of great frequency, you could guess that they meant "eins" and work from there. This could unmask the daily code key much faster. Luftwaffe code operators were sloppy about the codes they used, and those bad habits provided clues as well. The British were brilliant in targeting German naval and weather vessels, and sinking them in ways so that codes and code machine parts could be saved. In some cases, Japanese embassies were broken into and codes directly stolen. The most fascinating parts of the book come from the descriptions of how raw brain power solved problems. Many new code-solving techniques were developed. The Poles (especially Marian Rejewski) deduced the structure of the German Enigma machine just through examining the encoded message structures, and built one. Later, Turing took the idea of linking Enigma machines together to test patterns and developed a process for finding which settings were being used each day. Almost unbelievably, ideas and machines came along later that greatly improved the efficiency of this process even further.If you like puzzles, you will love the discussions of the codebreaking technques because they employ detailed descriptions of the codes, code machines, and the exact methods used. Many wonderful diagrams of wiring and logical connections make this transparent for those who are interested in fully understanding. If you are not so interested, you can skip ahead to the material that interests you instead.Emotionally, you will find yourself riveted by the races between the code breakers and the pace of unfolding battles. In several instances, such as at Midway, in the North Atlantic convoy runs, in North Africa, and during the Battle of the Bulge