Breaking the Enigma code
Polish contribution to victory

Andrzej Dabrowa, Ph.D.

Enigma machine M Rajewski H Zygalski J. Rozycki
Chapters
  1. Synopsis
  2. Historical background
  3. Breaking the Enigma Code
  4. Polish decrypting effort 1930-1939
  5. Polish decrypting effort 1939-1945
  6. English decrypting effort - the beginnings
  7. England - Bletchley Park
  8. United States in the secret war
  9. Battle of Britain
  10. British northeast Africa
  11. Invasion of French northwest Africa
  12. Battle of the Atlantic
  13. Battle of the terror weapons V1 & V2
  14. German atrocities
  15. Enigma security
  16. Conclusion
  17. Epilogue
  18. References

16. Conclusion

The wise use of Enigma intelligence shortened the war by six to twelve months, reduced the suffering of millions of people under German occupation, saved the lives of hundreds of thousands of people in German concentration camps, saved the lives of a hundred thousand Allied soldiers, reduced damage to property and prevented the march of the Red Army into Western Europe.

It was only in 1973, when Gen. Bertrand published his book entitled "Enigma ou plus grande engine de la guerre", that the first account of Enigma operations became public. This was followed by "Ultra Secret" written by F. W. Winterbotham in 1974. In 1981 M. Rejewski, who developed a mathematical approach that led to breaking the Enigma code, wrote a paper in the Polish Mathematical Journal describing in detail the method he developed to crack the cipher. Since then a number of articles and books have been written giving accounts of the Bletchley Park operation. The titles of well-documented books that were used to prepare this article are given in the reference section. Many more were published by lesser known authors and publishers and in limited numbers. Bletchley Park Ultra operation was successfully kept secret for many years after the end of WW2. Major figures of those days kept their word to Winston Churchill and took their secret to the grave. Churchill, the British Prime Minister, was an ardent supporter of Ultra Operation and had an absolute belief in the value of Enigma generated intelligence. Three of his quotes that have been recorded:

  1. On the Bletchley Park operation and it's absolute security:" the geese that laid golden eggs and never cackled"
  2. On the daily briefings he received on Enigma intercepts: "my most secret source"
  3. On the Battle of Atlantic and the help he received from Enigma Intelligence: "The Battle of Atlantic was the dominant factor throughout the War"

Another leader of comparable standing was the Allied Forces Commander-in-Chief Gen. D. D. Eisenhower, under whose command plans were made for the invasion of Europe. He clearly understood the benefits and advantages given by Enigma and the "Fish" intelligence as stated in his letter to Gen. S. Menzies Chief of British Intelligence (MI6) in 1945: "The intelligence which has emanated from you before and during this campaign has been of precious value to me. It has simplified my task as commander enormously. It has saved thousands of British and American lives and, in no small way, contributed to the speed with which the enemy was routed and eventually forced to surrender. I should be very grateful, therefore, if you would express to each and everyone of those engaged in this work from me personally my heartfelt admiration and sincere thanks for their very decisive contribution to the Allied war effort."

The benefits of Enigma intelligence were numerous and weighed heavily in the Allied victory over Germany whether it be in the advance planning, finding the enemy's weak points, running operations or in the details of particular engagements. The first benefit of Enigma intelligence was realized in preparation for and during the Battle of Britain, which was supposed, in the words of Hermann Goering "to wipe out the British Air Force from the sky". This all out attack was in preparation for "Operation Sea Lion", the invasion of Britain by the German Army. Marshal of the Royal Air Force, J. C. Slessor, made the following remarks about Air Marshall H. C. T. Dowding's successful handling of the Battle of Britain and the criticism he suffered: "he had known so much from Ultra of the Luftwaffe's plans through the Battle of Britain .. I know that in his place I should have been sorely tempted to use my knowledge of it to confute more junior critics who, unfortunately but quite rightly had, for security reasons not been admitted to this priceless secret. Dowding honourably kept his secret, and was sacked". Faced with the loss of air superiority, Hitler was forced to delay indefinitely the invasion of Britain. Even if the Germans had decided to invade Britain, it is doubtful whether they could have transported a sufficient number of troops in a short enough period of time since they had no previous experience of combined operations on that scale.

What is certain is that the casualties, on both sides, would have been substantial. The question as to whether the Battle of Britain was the most important is moot, because if the Germans had succeeded history would have been totally different! But there were much bigger battles to come and to be won with the help of Enigma and "Fish" intelligence. There is no doubt that the Battle of the Atlantic was the most important battle of WW2 and that Enigma played its greatest role. Britain's existence and the future conduct of the war depended heavily upon the Allied ability to ship food, supplies, arms and troops to Britain. Early in the war, Allied merchant shipping losses caused by German U-boats were staggering and shipyards had difficulty in replacing the sunk vessels. Furthermore, each replaced merchant ship meant one less naval vessel. Monitoring German Navy radio traffic and direction finding permitted the Allies to route convoys around German activity areas and to reduce the merchant ship losses but it contributed little to the fight against the U-boats! The German Navy Enigma code was very difficult to break, forcing the British Navy to seek and capture German ships to obtain the documents and code books needed to break the code. Once the cipher was broken, the merchant convoy losses were drastically reduced and pinpointing U-boat locations permitted the Allies to track, chase and sink them at an ever increasing rate. Enigma solutions prevented U-boats from dominating the Atlantic Ocean in the second half of 1941 and then in the winter of 1942/1943. Finally breaking the "Triton" Enigma code in May 1943 allowed the Allies to take the initiative and win the Battle of the Atlantic. Marshal of the Royal Air Force J. C. Slessor who, as Commander-in-Chief Coastal Command in 1943, had an intimate knowledge of Enigma intelligence relating to the Battle of Britain and Atlantic stated: "But I have the best reason to know that in the Battle of the Atlantic Ultra, in conjunction with High Frequency Direction Finding, was a real war winner. As Commander-in-Chief Coastal Command in 1943 I made a habit, at specially critical times, of attending the regular morning conference over the scrambling telephones between Roger Wynn at the Admiralty, Max Horton's Headquarters in Liverpool and my own at Northwood - by the end of which there was little or nothing we did not know about what the U-boats were up to in the Atlantic at the time". In military campaigns timing is of utmost importance and can make the difference between success and failure.

From the beginning of the war the British had information, through several sources, that the Germans were experimenting with rocket driven weapons. Massive bombing of Peenemunde and associated factories forced the Germans to move further east, out of the range of bombers, and delayed the use of these weapons by at least six months. The timing of these bombings was specially selected to coincide with the weapons research maturing and going into production. This was done to assure maximum damage and to maximise the delay in production until the Allies had a chance to move into occupied Europe. This was enough to allow the Allies to launch the invasion of Europe two weeks before the start of the V1 and three months before the V2 offensives! Had the invasion of Europe been delayed by several months there would have been major carnage and havoc, the invasion would have ended in a stalemate and the Red Army would have marched across the whole of Europe!

One cannot avoid the fact that the Battle of Britain, the Battle of the Atlantic, the heavy bombing of German cities, military targets and industrial centres, routing the Germans from North Africa and the massive concentration of troops and arms in Britain was a logical step towards the successful invasion of a well-defended Europe. Such a step had no precedent in military history and had to be extremely well planned and executed! This was when the use and value of Enigma reached its peak. Planning a beach landing required knowledge of the German defence plans with the precise location, strength and equipment of the defending army. Further, as the invasion forces moved inland, knowledge of German weak and strong points would allow the Allies to move forward without reaching a stalemate. All that information was copiously available from Enigma intercepts before and during the invasion and throughout the rest of the war!

Knowing the precise location and strength of the massive German tank concentration at Caen allowed the Allies to change their plans, choose more advantageous positions and to pinpoint the panzers. Another example of the use of Enigma intercepts was in the battle of Falaise which permitted Gen. G. S. Patton to use Blitzkrieg on the Germans and to move forward fast. Group Captain F. W. Winterbotham in charge of the Special Liaison Unit at Bletchley Park, had an intimate knowledge of Enigma intelligence, its use by various commanders and its value in the war effort. He states in his book entitled "The Ultra Secret": "After the fall of Falaise, the Ultra shortened the war by giving all the Allied commanders details of the weak points and the dwindling resources of the enemy so that they could go forward as natural hazards would let them. This was important in view of the advancing Russian Armies. Without Ultra we might have had to meet the Russians on the Elbe, and they would have stayed put." Gen. Alexander in Tunisia in 1943 said: " The knowledge not only of the enemy's precise strength and disposition but also how, when and where he intends to carry out his operations has brought a new dimension into the prosecution of the war." Surprise is the most valuable ingredient of modern warfare and the ability to deny information to an unsuspecting enemy is to achieve for one's self one of the elements of victory.

Finally one scholar's view, as quoted in the book written by D. Khan entitled "Seizing the Enigma": "Ultra created in senior staff and at the political summit a state of mind which transformed the taking of decisions. To feel that you know your enemy is a vastly comforting feeling. It grows imperceptibly over time if you regularly and intimately observe his thoughts and ways and habits and actions. Knowledge of this kind makes your own planing less tentative and more assured, less harrowing and more buoyant."

We see from the above Enigma discussion that the leading figures of WW2 agreed that the Enigma Intelligence was a major contributor to winning the war. The Allies would have won the war without the Enigma intelligence by using the atom bomb but the war would have lasted much longer and would have been more costly in terms of human lives, destruction and cost to the Allies.

This however did very little for Poland which was abandoned by the Allies to the "mercy" of communism. Fifty-five years of oppression brought economic disaster and personal suffering to its thirty-five million people.

The British, having learned a hard lesson how vital it is to have the ability to read an enemy's orders, implemented a long term post war plan to:

  1. Maintain absolute secrecy that the Enigma code could be broken for as long as possible
  2. Collect as many Enigmas as they could in Europe. Most of them were probably sold to unsuspecting governments, allowing the British to read their diplomatic mail.

(c) 2003 A R Dabrowa