Ultra in World War II
Story by Isabella Kates, photograph by Mauro Sbicego
The Weimar government of Germany purchased the Enigma machine from its inventor, Arthur Scherbius, in 1923 as previous cryptographic devices had been solved by other countries and security issues were prevalent. The Enigma machine functioned by having its rotors move to keep the cipher changing continuously every time a key was pressed. It was particularly valuable because it was the first rotor-based cypher machine of its kind. Settings of its four rotors contained approximately 158,000,000,000,000,000,000 possible solutions that made it extremely challenging to decode. Because of this, the Germans regarded the Enigma machine as unbreakable and therefore disregarded proper security precautions. The machine was also vulnerable in that no letter would ever be coded as itself (the premise upon which all code-breaking efforts were based).1
Polish intelligence took the first steps in breaking the Enigma by developing a similar machine called the bomba. After Germany invaded, the British continued these efforts. Bletchley Park, the headquarters of Britain’s Government Code & Cypher School, became MI6’s center for cryptanalytic research and counterintelligence. The only way the Enigma could be solved was by acquiring stolen keys. So, codebreakers utilized materials from German ships and submarines. The capture of the German submarine U-110 in 1941 provided invaluable information such as codebooks describing the patterns of rotors for each day, wireless logs of conversations, and an undamaged Enigma.2
By 1943, engineers Alan Turing and Tommy Flowers had devised a complex machine to decipher and transcribe German intercepts. The device, named Colossus, could handle the thousands of intercepts arriving daily at Bletchley Park. The massive task of transcribing and photographing decoded messages for storage in the archives was greatly reduced since Colossus transcribed the messages, in the original German, directly onto a typewriter. British Intelligence soon realized Colossus was so efficient that it could decipher messages more rapidly than even the intended recipients. Bletchley deciphered an estimated eight to fifteen thousand messages during the war, proving pivotal.3
Ultra enhanced radar by determining the difference between decoy ships and real watercraft and provided intel on the number of German ships.4 The codebreakers at Bletchley Park additionally figured out which Allied maritime codes had been compromised, allowing Allied ships time to relocate to a different point in the Atlantic before German U-boats arrived. As the Battle of the Atlantic developed, Ultra’s contributions only grew. The ability to concentrate naval forces on the critical convoys enabled the Allies to use their resources more efficiently.
For example, Bletchley Park detected Operation Paukenschlag, the U-boat campaign along the eastern seaboard of the United States after Pearl Harbor, in advance and responded to the threat.5 Having foresight into the enemy’s plan shaped Allied successful strategies.
Moreover, Bletchley Park supported land operations by persuading the Germans that the Normandy invasion would be a feint. Field Marshal Bernard Montgomery and General Dwight Eisenhower sent false messages to each other using a code they knew the Germans had broken. From Ultra intelligence, they learned that their deception had convinced Hitler that Pas de Calais was the target of the incoming invasion. Hitler diverted a significant number of troops there, lessening the defenses on the northern Normandy beaches. Furthermore, Bletchley Park intercepted Hitler’s order during the battle to move four divisions of troops with tanks to the front of Gold Beach, giving the Allies time to prepare for the incoming forces.6
Edgar Williams, a high-ranking British Army officer, remarked that Ultra “was the only source of revealing the enemy’s reaction to a cover plan. Without Ultra, we should never have known…” (referring to the four divisions of troops). The information Bletchley park decoded made D-Day possible through strategy that limited the loss of Allied lives.
Ultra was also used in approaches to the Battle of Monte Cassino, Battle of Anzio, and Operation Mincemeat. It was also used to gain the advantage on the North African front both defensively and offensively, effectively giving Allied forces access to Southern Europe.
Yet the true value of the Enigma machine is highly contested.
David Khan, an established cryptography scholar and author, claims that, while Ultra reduced the time it took for World War II to end, it proved more useful in tactical and operational areas than strategic ones. He posits that, by the time Ultra was fully functional, there were no longer any German strategic decisions left to learn.11
In contrast, Telford Taylor, a Harvard educated intellectual who served in several high government positions, asserts that Ultra had a negative impact. He argues that lives were lost from Ultra intelligence and that Bletchley Park contributions like Colossus did not shorten the war. In his speech to the American Historical Association, Taylor references the Ardennes offensive during the Battle of the Bulge. Allied intelligence staff were aware that the Germans had assembled the Sixth Panzer Army in the area east of Aachen. However, the positioning of its divisions was misinterpreted by Allied intelligence as replacing units being moved out rather than as the preparation for a massive counteroffensive, resulting in 75,000 Allied casualties. Taylor cites military leaders’ over-reliance on the tool as its failure.12
Regardless of how one interprets the impact of the Enigma machine on World War II, the machine reveals the interesting question of technology’s role in war and war’s role in technology. After all, the existence of the Enigma machine necessitated counterintelligence advancements to beat it and the existence of war necessitated the invention of the Enigma machine in the first place. Similarly, governments of today are constantly racing to develop new militaristic tech like lethal autonomous weapons systems. Throughout time, fear of conflict and conflict itself are unequivocally tied to both the death and destruction that sets societies back and the technological developments that propel them forward.
Notes
1 Gladwin, Lee A. Alan Turing, Enigma, and the Breaking of German Machine Ciphers in World
War Two. N.p., 1997.
2 Deutsch, Harold C. "The Historical Impact of Revealing the Ultra Secret." Parameters:
Journal of the U.S. Army War College, October 26, 2006, 17-29 and Erskine, Ralph. German Naval Enigma M4 Messages. Unpublished raw data, 1943.
3 Ibid.
4 Kahn, David. "Codebreaking in World Wars I and II: The Major Successes and Failures, Their
Causes and Their Effects." The Historical Journal 23, no. 3 (1980): 617-39.
5 Showalter, Dennis, and William Kautt. "Ultra: Was the Role of Ultra Decisive in the Outcome
of the War in Europe?" In History in Dispute, 260-265. Vol. 4. Detroit, MI: St. James Press, 2000.
6 Spiller, Roger J. "Some Implications of ULTRA." Military Affairs 40, no. 2 (1976): 49-54.
7 Lerner, Adrienne Wilmouth. "Ultra, Operation." In Encyclopedia of Espionage, Intelligence
and Security, 184-186. Vol. 3. Detroit, MI: Gale, 2004.
8 Gladwin, Lee A. Alan Turing, Enigma, and the Breaking of German Machine Ciphers in
World War Two. N.p., 1997.
9 U.S. Army Center of Military History. "Battle of the Bulge."
10 Gladwin, Lee A. Alan Turing, Enigma, and the Breaking of German Machine Ciphers in
World War Two. N.p., 1997.
11 Kahn, David. "Codebreaking in World Wars I and II: The Major Successes and Failures,
Their Causes and Their Effects." The Historical Journal 23, no. 3 (1980): 617-39.
12 Deutsch, Harold C. "The Historical Impact of Revealing the Ultra Secret." Parameters:
Journal of the U.S. Army War College, October 26, 2006, 17-29.
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