Obit of the Day: Breaking the Enigma
One of the most important factors in the defeat of the Germans during World War II was the Allies’ success in breaking the codes created by the Nazi’s “Enigma” machine. The machine, invented in 1919, and modified several times over the next twenty-five years, was considered completely secure and impossible to decipher.
The Polish government, using mathematicians, was actually able to break the early Enigma machine’s code system and even build replicas. But after the invasion of Poland in 1939 they passed on their Enigma information to the French and British.
Although both countries had success in unlocking the mysteries of the complicated code system, it was the British who made major leaps.
Mavis Batey was recruited to the Enigma project when she was only nineteen years old. Selected because of her knowledge of German - she was undertaking coursework for a degree in the language at Oxford when the war broke out - she was sent to work with legendary, and eccentric, codebreaker Dilly Knox at Bletchley Park.
Mrs. Batey was one of the “break-in” specialists who helped to decipher Enigma codes that had not been broken. Her first success came when she broke the Enigma code for the Italian Navy. After her first success, which read simply “Today is the day minus three,” she and her colleagues spent those three days trying to figure out the navy’s next move.
They determined that a Royal Navy supply convoywas to be the focus of an attack on the Mediterranean Sea. Which this knowledge, the Royal Navy turned the table and through some additional trickery surprised the Italians in March 1941, destroying five vessels with the loss of over 3000 Italian sailors.
Mrs. Batey’s biggest triumph, while working with Mr. Knox and fellow codebreaker Margaret Rock, was figuring out the Enigma used by the German Abwehr, or secret service. Unlike the traditional Enigma which used three wheels the Abwehr model had four wheels, making deciphering code exponentially harder. (One mathematician determined that Allied codebreakers had to deal with a possible 107, 458, 687, 327, 250, 619, 360, 000 permutations on a traditional 3-wheel model.) It was Mrs. Batey who decoded the first Abwehr message on December 8, 1941.
Once the Abwehr code was broken it lead to the success of the D-Day invasion at Normandy. Mrs. Batey and the others at Bletchley Park learned that the Germans had fallen for the MI5’s “double cross” plan and believed that the June 6, 1944 invasion would land at Calais. Adolf Hitler made sure that two armored divisions remained at Calais - reducing his tank forces at Normandy.
Following the war, while her husband, Keith, a fellow codebreaker, worked at Oxford University, Mrs. Batey developing an interest in land and garden preservation. She would write three books on historic garden in England and became president of the Garden History Society and was named a Member of the Most Excellent Order of the British Empire (MBE) for her work on garden preservation.
Mavis Batey, the last of the Bletchley Park “break-in” group, died on November 12, 2013 at the age of 92.
Sources: The Daily Telegraph, PBS.org, HelpNet Security (YouTube), codesandciphers.org, "The Theoretically Possible Number of Engima Configurations" and Wikipedia
(Image of Mavis Batey and her Keith Batey, while they worked as codebreakers at Bletchley Park in 1942 is courtesy of the Daily Mail from an article where Mrs. Batey criticizes Kate Winslet’s portrayal of a female codebreaker in the film Enigma.)