"Battle of Wits presents the history of the war that these documents reveal. From the Battle of Midway until the last German code was broken in January 1945, this is an astonishing epic of a war that was won not simply by brute strength but also by reading the enemy's intentions." "This is the story of the Allied codebreakers puzzling through the most difficult codebreaking problems that ever existed. At the same time, the compelling narrative shows the crucial effect codebreaking had on the battlefields by explaining the urgency of stopping the wolf pack U-boat attacks in the North Atlantic, the burning desire in the United States to turn the tide of the war after Pearl Harbor, the importance of halting Rommel's tanks in North Africa, and the necessity of ensuring that the Germans believed the Allies' audacious deception and cover plans for D-Day."--Jacket.

Includes maps of: Battle of Midway; Bletchley Park; Wartime Washington; Mediterranean Theater; Atlantic Convoys.

Prologue : Midway -- "No good, not even for intelligence": The end of the black chamber ; William F. Friedman picks up the pieces ; "I had the good sense to get out of it!" ; Room 40 ; Winston Churchill, an early convert ; The foreign office, a late convert ; The Soviet intercepts ; A strategic failure for intelligence -- Nature of the beast: The birth of codebreaking ; Machine ciphers, Poland, and the Enigma ; Depth reading ; The distinct limitations of thievery ; Solving the Red machine -- "Il y a du nouveau": 1939, a dark new year ; Meeting at Pyry Forest ; Marian Rejewski's mathematical feat ; Recovering the daily Enigma keys ; Alan Turing and other "men of the professor type" ; Bletchley Park ; The Poles' flight -- Fighting back: British mathematicians vs. the Enigma ; The bombe takes shape ; "A pile of dull, disjointed, and enigmatic scraps" ; Cryptanalytic talent ; Norway and yellow ; France and red ; HMS Glorious -- Impossible problems: The sinking of U-33 ; Naval Enigma and the bombe ; Operation Ruthless and other straws ; American isolationism ; Purple ; The British charm offensive ; A mission to Bletchley, bearing gifts -- Success breeds success: The blitz ; Cape Matapan ; Boniface, Barbarossa, and Bismarck ; Naval Enigma, U-110, and the trawler pinches ; The eastern front and German atrocities ; Trafalgar day ; Cribs and continuity -- The machines: The British make polite noises ; IBM machines and JN-25 ; The machine attack on Floradora ; Washington at war ; Military vs. civilians ; An American ultimatum ; Better bombes ; High-speed analyzers -- Paranoia is our profession: Dönitz's suspicions ; The evacuation of Corregidor ; The Midway leak ; Some bungled operations ; "Do not talk at meals" ; Suspicions among friends -- The shadow war: Calling the shots in the Mediterranean ; Torch and deception ; The flight from Vichy ; Atlantic convoys ; U-559 and the breaking of Shark ; The hunt for leaks ; The American invasion ; Pressures and diversions ; Women in uniform -- Command of the ether: Russian espionage and Project Venona ; GEE and fish ; Masters of deception ; Yamamoto ; The water transport code ; Failure in the Ardennes ; Signaling the end -- Epilogue : Legacy.