Cryptography

The History and Mathematics of Codes and Code Breaking

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Navajo Code Talkers — Beyond Encryption

Though German Overconfidence in Enigma was a key factor to their loss, another major impact was the Navajo Code Talkers. The Navajo Code Talkers success can be considered just as important and the code breaking of the Enigma. Without secure communications it is hard for the Allies to fight back in an organised manor. With the Navajo Code Talkers, the Allies were able to have some of the most secure communications in the war. What made the Navajo Code Talkers so important is the language they spoke and the amount of people who spoke it. The Navajo language is extremely rare as well as the people who speak it. With a rare unrecognizable language being introduced in the war the Allies had a huge advantage. This, in my opinion, can be considered a type of double encryption. The first layer being the Navajo language and the second being the encryption of it. The language had two flaws, the military jargon translations and its weakness to frequency analysis. These weaknesses were serious yet the code was still not broken. Considering how successful the Navajo Code Talkers were, the method as well as the encryption of the code must have been very secure. Thanks to the Navajo Code Talkers, the Allies were able to establish a secure line of communication.

The Allies’ Teamwork Against the Germans’ Human Error

While the Germans’ overconfidence in the strength of Enigma was a primary factor leading to their loss in the World War II, I believe how the Allies worked in a united and coherent way also significantly influenced the outcome of the battle of cryptography. The French Secret Service first obtained the documents that suggested the wirings of the military Enigma machine, and then handed them to the Poles so that the Biuro Szyfrów could try to crack the Enigma with such a starting point. Furthermore, after the Poles successfully broke the Enigma cipher for several years but were no longer able to decipher the Germans’ messages when more scramblers and plugboard cables were added, they offered their code-breaking techniques to the British and the French, letting them continue the decipherments. Therefore there came the stories at Bletchley Park and Alan Turing’s well-known accomplishments. If any one of France, Poland and Britain was unwilling to share its information and works with others, the Allies might not break the Enigma because no one would have enough resources indispensable to cracking the codes.

In comparison to the Allies’ teamwork, the Germans, interestingly, compromised their own cipher. Germans are always acknowledged as procedural and rigid; with these characteristics they sometimes yielded advantages in the war in which the order and decisive operations mattered. However, their adherence to rules also resulted in flaws in their encryption. The repetition of message keys, and the rigidly structured weather reports were exploited by the Allies to crack the Enigma. Without the human error on the German side, it would take the Allies more time to break the code and end the war.

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One overlooked important contribution to Allied success in cracking Enigma was that the Allies had knowledge of the structure of Enigma machines; had the Germans kept Scherbius’s invention as classified as possible—including exactly how many scramblers were used and the plugboard—efforts on the Allied side would have been much more stymied by pure bafflement of how the text could have even been conceived. Without knowing that there were scramblers, how many of them were employed, and how they worked, their progress would have been much more set back. They wouldn’t even know where to start, since all previous methods of decrypting messages would render to be useless. To guess out of the blue that there are 3 scramblers in effect in addition to a plugboard would have required some great intellectual leaps itself. 

Another flaw lies in the inherent structure-oriented nature of militaries.They always fall to regimented schedules, customs, and chain of command. In a way, they are sort of formulaic. In ROTC, we often write up memorandums, which is the main way formal messages are communicated through the detachment, and they always follow a certain template: the date is always in a specific location and distance away from the edge of the paper, the first line is always “MEMORANDUM FOR…”, the line after that is always “FROM”, and the line after that is always “SUBJECT.” Knowing this, the intense structured military environment allows no room for subjectivity, which reduces individual creativity and expression. It will always follow an objective that has been laid out for someone to fill in the blanks. Its repercussions can be seen in two areas: the location and repetition of the scrambler settings for the next message and the weather report that usually came at 6am every day. 

Had the weather report not contained the German word “weather” as the second word of each message and rather been incorporated into differently structured sentences (today’s weather is…the weather for today…it appears that it will rain at 1600 today…etc.) this would have drastically reduced the amount of cribs available for the code breakers. Unfortunately, under normal circumstances, it is unfavorable to deviate from the norm. Because that’s not how militaries work. In the military, they rely on unison and synchronicity. If a soldier decided to put a potentially life saving device in a pocket that was not designated for that device and ended up in a life threatening situation, he might not make it because other soldiers count on the fact that that device will always be in a specific pocket, which in this case is not. This wastes time and reduces efficiency. These are some other important factors that led to Allied success in cracking Enigma.

 

References: Photo from https://www.memecenter.com/fun/164162/ctrl-c-ctrl-v.

The Allies Work Better Under Pressure

It is no secret that Allied code breakers bested German code makers during World War II which contributed enormously to an Allied victory in the war. Germany’s overconfidence in the strength of its Enigma cipher definitely contributed to the Allies’ code breaking success, but another main contribution was the pressure that Germany forced against the Allies. The Allies were on their heels trying to defend against Germany, which led countries to band together and individual cryptographers to band together to fight a common enemy. The necessity for the Allies to break Enigma in order to thwart the Axis’ attacks brought Poland, England, France, and America together which gave them the resources to crack Enigma and Purple (Japan’s encryption method).

Without the pressure the Axis powers were putting the Allies under, they would not have felt the urgency to break Enigma and Purple. The Allies won this war on intelligence because they were on the defense and needed to break Enigma and Purple in order to turn the tables against the Axis, while the Axis got complacent and confident about their machines because they were able to advance through Europe and the Pacific without their code being decrypted. Since the Allies were under such pressure, they had to find a way to gain the advantage. Therefore, countries such as Poland and England teamed up and individuals such as the mathematicians at Bletchley Park teamed up to crack the Enigma and Purple ciphers. Without the pressure that the Axis’ exerted on the Allies, the Allies would not have been so desperate to find any way possible to crack Germany and Japan’s seemingly unbreakable ciphers.

Divided and Conquered

The Allied cryptanalysts were victorious over the German cryptographers due to a variety of reasons; however, one rather simple reason is often overlooked: the allies had a much larger and much more unified base of cryptologists than the Germans.

Germany had a total of around 30,000 people working in the intercepting, decoding, and coding of messages. The European Axis powers had a grand total of 36,000 people working in those endeavors. The Allied powers had a number closer to 60,000 people doing the same jobs, nearly twice that of the Axis powers. Just think about the implications of this: more people leads to more intercepted messages, which leads to more cipher text to work with (a historically beneficial resource in terms of breaking codes), and more people leads to more brain power trying more techniques to break the same code.

In addition to this, Germany did not have a central cryptology base like the Allies did at Bletchley Park. The Germans were spread out among 6 different bases, and would often overlap in each other’s efforts, duplicating each other’s work and thus wasting time and resources. There was some collaboration but not nearly to the degree of the Allies. In Andrew’s blog post, he discusses the importance of collaboration in the field of cryptology so I will not expand upon this as much.

Finally, the Germans never created a bombe-like machine that could decipher messages which can very easily be attributed to the division and smaller size of the German forces. Without this key technology, Germans had to do a lot of the leg work manually which is much much more time-consuming and much less reliable. The bombe and other machines like it (Colossus and Tunny) exponentially increased the cryptographic progress of the Allies, catapulting them far ahead of the Axis powers.

 

Click here to see my primary source.

German Cryptography is still Human Cryptography

During WWII, Germans sent out thousands of messages encrypted using the supposedly unbreakable Enigma machine. It was discovered after the war that German intelligence knew that these messages could be captured by the Allies, but they could not think anyone would have the time or resources to possibly decipher them. This strongly held idea that Enigma was unbreakable was perhaps the greatest mistake of Germany.

Another factor, besides German overconfidence, that allowed the Allies to decipher German messages were the patterns discovered when Enigma was used. These patterns were precisely the result of non-randomness that describes human nature. Some keys were easily guessed because the letters on the Enigma keyboard were next to each other. Other keys may have been similarly predictable because they resembled German names, or they were used repeatedly. These were called “cillies.” Ironically, an effort to consciously combat human un-randomness was also a mistake on Germany’s part. By avoiding “obvious” plugboard settings and arranging rotors to avoid repeated positions, the amount of possible settings were drastically reduced.

Human nature in and of itself is never truly random; this is a basic fact we learn in our statistics classes. If you asked a population to randomly choose a number between 1 and 4, would a fourth of the people choose each of the numbers? Polls have shown that, instead, a clear majority would choose the number 3. In the same manner, cipher keys are not always a random garble of letters. They are often derived from meaningful words or phrases that may be pertinent to the message or the receiver/sender of the message.

Rejewski and Turing

One of the main reasons for the success of the Allied cryptanalysts at Bletchley Park over German cryptographers is the acquisition of the previous work of the Polish on the German Enigma. Polish cryptanalyst, Marian Rejewski, led the polish to first break Enigma in 1932, and kept up with breaking any new security the Germans implemented to strengthen Enigma, until in 1939, when the Germans increased the number of plugboard connections from 5 to 8 to 7 to 10, which made cryptanalysis extremely more difficult. This spurred the Polish to disclose all their work on Enigma to the Allies, especially as the likelihood for another war was growing. Thus, when war broke out and the need to break Enigma became of utmost importance, the Allies had a head start on breaking the codes, as they already had acquired intelligence on Enigma.

Another curious and more indirect reason why the Allies were ultimately successful was because Britain never found out that Alan Turing was a homosexual. Turing was the one of the most important men in the war in that he led the cryptanalyst team at Bletchley Park to victory in breaking Enigma. At the time, homosexuality in Britain was illegal and it was very fortunate that the state never found out about Alan Turing’s case during the war, otherwise Turing probably would never had made it to Bletchley.  Needless to say, if Turing had not been working for the Allies during the war, Enigma may never have been broken and the Germans may have won.

Allies versus Germans: they won because they were Allies

It is my opinion that one of the prominent and yet overlooked reasons that the Allied cryptanalysts were able to end up winning against German cryptographers was that they were indeed Allies. Although there were times when they kept information from each other, they were able to share their breakthroughs in a way that Germany could not share with its allies. Every time an advancement in breaking the code was made it was possible for them to share that advancement with each other, and this allowed them to break more codes faster. Germany, on the other hand could not share breakthroughs with codewriting and codebreaking with its allies. This is for a pretty obvious reason.

The Allies were only intent on defeating Germany and its allies, to keep the world balance as it was. Germany and its allies were intent on conquering as much territory as possible. This meant that Germany was afraid to share information with its allies, because there was always the chance that once they defeated the Allies, they would turn on each other. An interesting parallel of this would be that of supervillains. The issue with them joining together to defeat superheroes was and is always that they can’t work together for very long before turning on each other.

The Allies could communicate with each other. Germany could not do so. This, as simple as it is, is one of the key reasons that the cryptanalysts worked so efficiently. The Allies were allies.

Ethical, Unethical, or Both?

I am of the opinion that there are two ways that the question can be looked at. Personal ethics, I think, are different than the ethics of a nation. This is something that must be taken into account when questioning the ethics of decisions surrounding national security; it most certainly must be taken into account when considering the Zimmerman telegram.

From a personal standpoint, this decision is unquestionably unethical. Letting America know the contents of the Zimmerman telegram would have saved American lives, and potentially shortened the length of the war. Although it could be argued that more lives might have been lost if Germany knew that the code had been broken, I vastly disagree. Creating a new and equally strong code for their messages would have taken Germany a long period of time, because creating codes that function and are very strong is not an entirely simple process. Even if Germany became aware that their code had been broken, with the advantage given to both America and Britain, the war may have been won before the new code was invented. It is completely unethical for someone to break a code with the intention of shortening the war, and then not use the broken code to save as many lives as possible.

At the other end of this issue is the standpoint of national ethicality.  It is my opinion that a nations ethics are typically focused first and foremost selfishly, on the survival of that specific nation. It is quite possible that Admiral Hall believed that telling the Americans about the contents of the Zimmerman telegram would jeopardize the very survival of his nation, in which case he simply obeyed his national ethics, which told him that survival came first. In following this duty to his country he also follows another part of national ethicality, that the homeland must come first.

With these two sides to keep in mind, it is impossible for me to conclude that one is more correct than the other. Personally, it is unethical. Nationally, it seems it may have been quite ethical. In the end, this is a murky issue. However, in the tumultuous and interconnected times we live in today, this will be an issue I think we will revisit very soon.

Strategical rather than unethical

After the Zimmermann telegram was deciphered, Admiral Hall chose to withhold the important information regarding the unrestricted submarine warfare and put many Americans’ lives on the line.

The decision itself at that moment seemed unethical because it resulted in the death of many innocent Americans. However, thinking in a larger scale, Hall’s action was justifiable. Firstly, given this war context, the ethical considerations probably weren’t be the top priority for people who dedicated themselves for the future of their country. Instead of thinking about whether their decisions might be ethical, they would probably spending more time weighing up the consequences of their actions, which, in Hall’s case, was the potential long-term consequences of disclosing their advanced cryptographic progression to the world. Hall realized that it might eventually make the British lose the advantage of using their advanced cryptographic techniques to gather the information that would be extremely valuable to them in the war.

Another text written by Sun-Tze in the Art of War says that “if you know your enemies and know yourself, you will not be imperiled in a hundred battles.” Sun-Tze’s words implies that in order to win the battle, not only should us try to gather as much information as we can about the enemies, but also try to avoid exposing any of our own progression to the enemies. That was exactly what Hall did. His action enabled the British to see through German’s plot while keeping the Germany in the dark, hence gaining significant advantages in the long run. In this sense, I believe that Hall’s decision shouldn’t be considered unethical, but simply strategical.

 

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