The Emperor's Codes: Bletchley Park's Role in Breaking Japan's Secret Ciphers [Paperback]

Right after World War II, the American cryptographers broke the story of how they had cracked the Japanese diplomatic code (the so-called Purple code). What was not known, until recently, is that almost all of success with the other Japanese codes involved British and/or Australian codebreakers. Even more surprising is that the U.S. Navy kept intercepts and code books from the British codebreakers despite agreements to share. Undoubtedly, many lost their lives and the war was prolonged because of these U.S. errors.

But there were also errors in using the coded output. Some commanders just wouldn't take it seriously, and placed their ships in harm's way. Consider the irony of the British decoding an impending attack on their codebreaking home in Ceylon which the British Navy largely ignored after the attack was delayed for a few days.

The Japanese codebreaking was much more difficult than that for the German codes because the allies had few Japanese readers to draw on. Before the war's end, the British invented a six month cram course that effectively taught code-breaking Japanese. Also, because the British lost so many bases in Asia, the codebreakers were pushed further and further away from Japanese bases and shipping. That meant an inability to get enough radio messages to be able to effectively decode. At the key turning points in the war, the British were trying to listen to Japan from a lousy station in Kenya. Go figure! Here's where the U.S. Navy could have made a big difference, because they always had lots of intercepts from naval shipping in the Pacific. "The record of the US Navy in cooperation, not just with the British but with their own Army, was not merely lamentable, it was shameful."

Interestingly, the Japanese codes were able to be broken mostly because the Japanese assumed that no one could. So when it appeared that the codes might have been compromised, they kept using the same ones. That gave the allies an edge. The Japanese also had some habits that helped. They began many messages with similar flowery language such as "I have the honour to inform your excellency . . . ." Find enough of those messages, and you could begin to decode.

It was fascinating to see how one source of intelligence helped other parts of the war. The Japanese ambassador in Berlin was a great source of information about Nazi Germany, through the broken Purple code. He toured Normandy just before D-Day, and his rambling account tipped the allies off to the need to throw Hitler's attention towards Pas de Calais.

The book also recounts how a broken message allowed the allies to shoot down Admiral Yamamoto. You also get a very fine explanation of how the coded messages were used to help win the Battle of Midway and the speed the liberation of the Philippines.

Long sections of the story are presented as quoted material from partipants, which provides a change in voice and of perspective. Many of the codebreakers in the various Asian locations were women. What was it like to find a giant snake in the toilet that you so desperately wanted to use? Many of those involved in codebreaking married, and had to deal with the many British retreats (from Hong Kong to Singapore to Colombo to Mombasa). Their stories will make all of this much more appealing and personal to you.

After you finish understanding how valuable it is to understand your opponent, think about your competitors in work or play activities. How well have you undertaken to understand what they are thinking about in order to anticipate what they will do next? For those you serve, don't forget that you can ask them directly.

Get to the bottom of important puzzles!

Right after World War II, the American cryptographers broke the story of how they had cracked the Japanese diplomatic code (the so-called Purple code). What was not known, until recently, is that almost all of success with the other Japanese codes involved British and/or Australian codebreakers. Even more surprising is that the U.S. Navy kept intercepts and code books from the British codebreakers despite agreements to share. Undoubtedly, many lost their lives and the war was prolonged because of these U.S. errors.

But there were also errors in using the coded output. Some commanders just wouldn't take it seriously, and placed their ships in harm's way. Consider the irony of the British decoding an impending attack on their codebreaking home in Ceylon which the British Navy largely ignored after the attack was delayed for a few days.

The Japanese codebreaking was much more difficult than that for the German codes because the allies had few Japanese readers to draw on. Before the war's end, the British invented a six month cram course that effectively taught code-breaking Japanese. Also, because the British lost so many bases in Asia, the codebreakers were pushed further and further away from Japanese bases and shipping. That meant an inability to get enough radio messages to be able to effectively decode. At the key turning points in the war, the British were trying to listen to Japan from a lousy station in Kenya. Go figure! Here's where the U.S. Navy could have made a big difference, because they always had lots of intercepts from naval shipping in the Pacific. "The record of the US Navy in cooperation, not just with the British but with their own Army, was not merely lamentable, it was shameful."

Interestingly, the Japanese codes were able to be broken mostly because the Japanese assumed that no one could. So when it appeared that the codes might have been compromised, they kept using the same ones. That gave the allies an edge. The Japanese also had some habits that helped. They began many messages with similar flowery language such as "I have the honour to inform your excellency . . . ." Find enough of those messages, and you could begin to decode.

It was fascinating to see how one source of intelligence helped other parts of the war. The Japanese ambassador in Berlin was a great source of information about Nazi Germany, through the broken Purple code. He toured Normandy just before D-Day, and his rambling account tipped the allies off to the need to throw Hitler's attention towards Pas de Calais.

The book also recounts how a broken message allowed the allies to shoot down Admiral Yamamoto. You also get a very fine explanation of how the coded messages were used to help win the Battle of Midway and the speed the liberation of the Philippines.

Long sections of the story are presented as quoted material from partipants, which provides a change in voice and of perspective. Many of the codebreakers in the various Asian locations were women. What was it like to find a giant snake in the toilet that you so desperately wanted to use? Many of those involved in codebreaking married, and had to deal with the many British retreats (from Hong Kong to Singapore to Colombo to Mombasa). Their stories will make all of this much more appealing and personal to you.

After you finish understanding how valuable it is to understand your opponent, think about your competitors in work or play activities. How well have you undertaken to understand what they are thinking about in order to anticipate what they will do next? For those you serve, don't forget that you can ask them directly.

Get to the bottom of important puzzles!