Spy vs. Spy
Jennifer Wilding

The popular image of spies is very glamorous. They lead perilous lives, full of danger, romance and excitement. Ian Fleming, who worked in British Military Intelligence before he created James Bond, is largely responsible for this perception. Having worked in Intelligence, Fleming certainly knew better.

Life for the few agents working undercover can be very exciting indeed. It can also be very short and undercover work is not where the main area of intelligence gathering takes place. Intelligence gathering consists largely of intercepting and interpreting messages. For this reason information is generally transmitted in codes or ciphers, the keys to which are closely guarded secrets. Each side spends enormous amounts of time, money and effort in developing unbreakable codes and trying to break the enemy's unbreakable codes. This work is not carried out by spies, but by mathematicians and scholars. One of the largest groups of code breakers during the Second World War was made up of Classical scholars, people adept at deciphering ancient manuscripts and solving the puzzle of unknown languages.

Nazi Germany came very close to the unbreakable code with the Enigma Machine.

In 1919 Dutch inventor Hugo Koth began marketing his Glow Lamp Ciphering and Deciphering Machine as a postal machine, to keep business transactions secret. The threat of industrial espionage was not an issue, and there was no particular market for it. However, Arthur Scherbuis, a German engineer, saw possibilities in it and developed the Enigma machine in 1923. This time there was interest, on the part of the German, Polish, Japanese and American military. Each nation purchased at least one machine before the German government bought the patent and made the machine a military secret. Germany, Poland and Japan began adapting the Enigma machines, the American model was packed away and forgotten.

The first military application of the Enigma was in February 1926, by the German navy. The Army began using in it in 1928 and in 1933 the Luftwaffe followed suit. During this time the Enigma had been developed and refined, the 'M' model replaced the original 'C' in 1934. It was an enormously complex machine, with interchangeable rotors. Electrically powered, it randomly selected a letter for any key pressed, never selecting the same letter twice. Pressing, for example, "oo" could produce any combination of two letters, selected completely at random by the machine. As the number of rotors increased the possibility of different meanings for each letter or code group increased exponentially. Too, altering the current settings could produce yet another completely random set of letters. To complicate matters for any enemy cryptography department deciphering an Enigma encoded message required the code groups for the day, the current settings, the correct rotor (which could go both backwards and forwards) and a correctly configured Enigma machine. It produced wholly indecipherable messages.

The Enigma machines were particularly valuable to the navy, where hand delivered secret messages were impossible. It made the German submarine wolf packs nearly invincible and supply lines to Britain came close to being cut during the Battle of the Atlantic. Breaking the code became of paramount importance to the British war effort.

The Japanese had also been working on their Enigma machine. It was radically refined and improved and eventually surfaced as the Alphabetical Typewriter 97, also known as The Purple Machine. It worked along the same principles as the German machine, but was a more complex problem for cryptoanalysis as Japanese was based on ideograms rather than a Western style alphabet. The secrets of the Purple Machine were eventually broken, but not until the German Enigma was solved.

The fate of the American owned Enigma is a peculiar tale. The US Signal Corps had acquired it in 1927, and the cryptoanalysis department had been working on it. However, in May 1929 Secretary of State Henry Stinson declared that "gentlemen do not read each others mail" and work on the Enigma was abandoned, as was virtually all cryptoanalysis. Signal Corps Major P.W. Evans had actually seen a German Enigma demonstrated and explained, his report was filed away.

The Poles, however, had been very busy indeed with their Enigma machine. The German threat was overwhelming, and the Poles were very aware that their position was perilous. They had never stopped intercepting and reading German messages and rapidly became expert code breakers. When Germany began using Enigma messages the Polish code breakers began trying to break them. It is estimated that by January 1938 the Poles were about 75% accurate in deciphering Enigma traffic. Part of this success may be attributed to the "Bomba", a sort of high speed calculator with bits of Enigma machines wired into it. It was more effective than anything else that had been developed, but was not really capable of solving the Enigma. When Poland fell in September 1939 some of the Polish cryptographers escaped, first to France and then to England, work on the problem began in deadly earnest.

Enigma was such an overwhelming problem that there was an entire intelligence department devoted to it, with a special designation, Ultra, a department beyond Top Secret. Work was largely carried on at Bletchley Park and eventually involved hundreds of mathematicians, Classics scholars, cryptographers, and others. Much of the success in cracking the Enigma was due to plain hard work, but there were also some spectacular lucky breaks. An Enigma machine and code book were captured when a signal man in a sinking German ship failed to throw them overboard in time. Polish underground members succeeded in getting machines to the British in daring missions that cost them their lives.

Cracking the Enigma was one of the largest covert operations of World War Two. It did involve dangerous missions that cost men's lives but mostly it was hard, tedious work. Eventually a machine similar to the Polish Bomba was produced and Enigma traffic could be deciphered in very short order. It was a vital step in defeating the wolf packs and, eventually, Nazi Germany.