The best books about how to break things (encryption, passwords, etc.)

Rarely can a book intertwine the inner workings, history, and applications of something--particularly when that something is a complicated topic like cryptography. But Simon Singh pulls it off with style. The Code Book delves into the history of ciphers, how they have been used, and how they have impacted history, from the 1500s through today. It also explains how these ciphers actually work, using language and illustrations that do not require a PhD in mathematics to understand. You will come away with a greater understanding and appreciation for how cryptography makes us more secure.

Passwords: everybody has them and everybody abuses them. Passwords can provide good security, but very few users use passwords correctly in order to take advantage of the protections they provide. The key to our poor implementation of passwords is a complete misunderstanding of how attackers break our passwords. Without this understanding users create weak passwords that are easy to break. Joshua Picolet's book is a reference guide for cracking passwords, but by explaining how to break passwords it also provides valuable information about how to make them strong to protect passwords from attacks. This book provides the proof of why we should treat passwords like our underwear: don't let people see it, change it often, and don't share it with strangers.

It is hard to underestimate the significance of code breaking during World War II. Without the work of dedicated mathematicians, linguists, and others the great conflicts such as the Battle of Midway and the German U-boat "wolfpacks" that sank over 13 million tons of Allied supplies could have easily been up for grabs. But due to the codebreakers the balance shifted to the Allies. And what is even equally impressive is that the Axis powers never knew that their encoded messages were being read. Stephen Budiansky traces how the codebreakers pulled off this feat while at the same time often battling within their own ranks about who should decode the message, how the messages should be used, and who should get the credit.

David Kahn explains the most widely-known effort (widely-known today but in complete secrecy then) to decipher messages sent by the Germans using their Enigma machines during World War II. This book looks at the groundbreaking work done by Polish mathematicians in the 1930s, how Enigma machines were rescued from sinking German U-boats, and how Bletchley Park in Britain became the focal point of breaking these transmissions. Much of the book focuses on how Enigma machines, rotors, and codebooks were confiscated from German submarines and surface vessels, and how these were then used to allow the Allies, by the war's end, to read German messages almost as quickly as the Germans could send them.

Perhaps the best book on the epic World War II Battle of Midway, Craig Symonds brings together all the pieces that became the turning point in the Pacific War. Looking at the leadup to the battle from both the Japanese and American perspectives, Symonds shows how the Japanese, in their typical style, created a battle plan that was overly complicated for its objective. Symonds explains how American Joe Rochefort and his eclectic band (he even had commissioned naval musicians) worked to bend (but not entirely break) the Japanese naval code. This allowed the Allies to surmise Midway as the Japanese target and set in place their own battle plan. Symonds clearly explains how the codebreaking efforts played a huge role in this battle of battles.