Prior to WWII, Germans improved upon a machine that became known as “Enigma” built in the 1920’s enabling a message to be encrypted before it was sent and then the process reversed to decipher it upon receipt. Easily carried in ships, submarines, air-planes and to army field stations. it used a series of rotating four inch wheels that scrambled plain text messages into unreadable gibberish. Since the wheels could be set into billions of positions, an unlimited number of combinations provided the German high command with the ability to transmit and receive Morse code messages without concern that the Allies would intercept and know their plans. During the early years of the War, Hitler’s armies enjoyed a tremendous advantage using this method.
In 1929, Polish mathematician Marian Rejewski attended a secret cryptology course conducted by the Polish General Staff’s Cipher Bureau, which he joined in September 1932. Rejewski deduced the coding machine’s (Enigma) secret internal wiring and with his two colleagues developed successive techniques for the regular decryption of Enigma messages. Five weeks before the German invasion of Poland in 1939, Rejewski and his colleagues presented their achievements to French and British intelligence representatives in Warsaw. Shortly after the outbreak of war, the Polish cryptologists were evacuated to France.
Dilly Knox, (1884 – 1943) a leading cryptologist, who cracked the code of the commercial Enigma machines used in the Spanish Civil War, was one of the British participants at the conference in which the Poles disclosed their achievements in Enigma decryption. Knox broke non-steckered Enigma machines (those without a plugboard) and developed a linguistic, as opposed to mathematical, way of breaking codes. This technique worked on the Enigma used by the Italian Navy and the German Abwehr. Knox worked next to Bletchley Park as head of a research section, which contributed significantly to cryptanalysis of the Enigma.
Bletchley Park, north-west of London (between Oxford and Cambridge), is one of the best known British sites from WW2. Its fame goes back to the code-breaking of the legendary Enigma cipher machine and its successor, the Lorenz cipher machine. In order to perform this work, the development of early computers took place here. The mechanical Bombe for breaking the Enigma, and the valve-based Colossus for breaking the Lorenz. Colossus was the world’s first electronic digital programmable computer. Two Englishmen, Alan Turing, (after whose name the coveted prize for artificial intelligence is named) and Gordon Welchman developed “The Bombe” using the fact that common words and phrases, such as names and weather were coded into most messages.
The brilliant mathematician Alan Turing cracked the Nazi’s Enigma code and because his individual achievements were so momentous, it’s sometimes forgotten that more than 10,000 other people worked at the Government Code and Cypher School, of whom more than two-thirds were female. These service-women played a pivotal role in an operation that decrypted millions of German messages and which is credited with significantly shortening the war.
After the War, a great shield of secrecy kept information about the Allied deciphering efforts from the public eye for more than fifty years. In 2009 Prime Minister Gordon Brown of the UK broke the silence to honour one of the last surviving code-breaking operatives, Margaret Fick.
Margaret Fick had been sent to the Isle of Man, just 17, to learn Morse code and join the secret German Intercept Service. From the listening station near Harrogate, she along with other listeners, copied thousands of coded messages and passed them along to the Bletchey Park group for deciphering. This whole operation was guarded and the Nazi high command never realized that the Allies knew their secret plans within hours. Hardly recognized as War heroines, these Morse code listeners played a tremendous role in shortening the war and bringing peace to Europe. Their contribution should be remembered and honoured.
Margaret Rock, Mavis Lever and Joan Clarke were all part of the civilian numbers and were first employed by the Foreign Office for clerical work. Mavis and Joan were recruited straight out of University in 1940 but Margaret was much older at 36 when she arrived, also in 1940. Margaret and Joan were mathematicians and Mavis a German Linguist. The Bletchley bosses wanted educated women but never expected, or planned for the fact that they could be as capable at cryptanalysis as their male peers.
Joan (Clarke) Murry’s ingenious work as a codebreaker during WW2 saved countless lives, and her talents were formidable enough to command the respect of some of the greatest minds of the 20th Century, despite the sexism of the time. The only woman to work in the nerve centre of the quest to crack German Enigma ciphers, Clarke rose to deputy head of Hut 8, and would be its longest-serving member.
The navy ciphers decoded by Clarke and her colleagues were much harder to break than other German messages, and largely related to U-boats that were hunting down Allied ships carrying troops and supplies from the US to Europe. Her task was to break these ciphers in real time, one of the most high-pressure jobs at Bletchley. Because of the secrecy that still surrounds events at Bletchley Park, the full extent of Clarke’s achievements remains unknown.
She was appointed MBE in 1947 for her work during WW2. She died in 1996
Mavis Batey – née Lever (5 May 1921 – 12 November 2013) Codebreaker
Midway through her course in German linguistics at University College London, just 19 years old, she arrived at Bletchley Park, where she was introduced to Knox. Shortly afterwards, in March 1941, she had her first success when she broke the Italian Naval Enigma code, something that would prove to be vital to the victory in the Battle of Cape Matapan. Her most important work however, was her collaboration with Dilly Knox and Margret Rock, another leading female codebreaker, on breaking the Enigma G, a special version of the Enigma machine that was used by the German secret service, the Abwehr. It had not been broken by Hut 6 and for a while was thought to be unbreakable. Mavis met her future husband Keith Batey whilst working at Bletchley Park. 2009 she wrote a biography about her cryptologist boss, Dilly Knox.
Margret Rock (1903 – 1983) With her degrees in mathematics and French from the University of London’s Bedford College, as well as her post-graduation work in statistics, it’s no surprise that in 1939 she went to work for the Government Code and Cypher School (CCCS) at Bletchley Park. She worked on cracking the German and Russian codes .In 1945 Rock was also appointed MBE.
The listener – Patricia Davies spent World War II listening – spending hours at a time trying to pick voices from squealing static. Davies was one of a room full of women scouring the radio waves and scribbling down nonsensical monologues. These messages were orders destined for German sub-marine bases on the west coast of France or ships in the Baltic Sea. Davies was a member of the Wrens who were capturing these communications and sending them by teleprinter to the code breakers at Bletchley Park, aka Station-X. The seemingly random jumble of letters were a code produced by the Enigma machine, which took the German messages and scrambled the letters in quintillions of different ways.
German orders weren’t just spoken but also sent as Morse code, and the series of long and short beeps the Germans used to open these messages stayed with Davies “They had a code that all ships used for heading and signing off, that always began with three letter groups, beginning with the letter Q.” Davies remembers messages carried by radio waves that had bounced off the earth’s ionosphere giving them intercontinental range. “We even accidentally picked up radio signals that didn’t seem to fit into the German naval pattern,” she said. “It turned out they were German tanks on the Russian front talking to each other. It was, of course, of no interest, but was rather eerie.”