The History and Mathematics of Codes and Code Breaking

Author: herbstts

The Interference of Secrecy









The Cryptonomicon brings up an interesting idea when Sergeant Shaftoe, Corporal Benjamin and Lieutenant Monkberg get in an argument after they ram their ship into Normandy. The reader already knows the purpose of the mission because it is alluded to in earlier chapters, but only Lieutenant Monkberg knows the exact orders, which causes problems when he tells them to do something that seemed like treason. The purpose of the mission was to leave behind the Allies' code book in order to have an excuse to change their codes, which they know the Germans have cracked, without alerting the Germans that they have cracked Enigma. Hiding the fact that they have cracked Enigma while still taking advantage of what they know  is basically the entire purpose of Detachment 2702. The concept of Detachment 2702 raises an interesting point because they have to deliberately hurt themselves in order to not reveal their resources. The concept behind 2702 is an answer to one of the things discussed in class, mainly the problem of revealing that a code has been cracked. Because of Detachment 2702, the Allies were able to fool the Axis into believing that Enigma was same and because of that, the Allies were able to keep a crucial advantage that was desperately needed in order to gain the upper hand in World War II. The Allies even had 2702 fooled, they couldn't possibly comprehend why they would ever leave behind the code book, though this secrecy turned into a double sided sword. When Corporal Benjamin is told to leave behind the code book, the Corporal assumes that his commanding officer is a spy and it didn't help that Lieutenant Monkberg was the only person that had received the orders. If they would have continue with taking the code book with them, they would have failed in their mission though they wouldn't realize it and it would have ended up costing Allied lives because the Allies would have needed to come up with a new way in which to justify switching code books, and until then all Allied conveys would be at risk of being destroyed by German U-boats.

Picture: U-Boat Surrender by Wessex Andy (Flickr)





The National Security Agency has one main priority, the protection analysis of communications, both domestic and foreign , that pose a threat to the United states of America. The NSA would be unable to do their job if they weren't able to tap into communications that
the NSA developed the Data Encryption Standard (DES) weak enough to be broken by them using means that were well wicould lead to a legitimate threat to the US. In order to do their job most effectively and not waste manpower developing new ways to break codes,within their grasp. In deliberately weakening the DES, the NSA left businesses and personal messages with a standard that wasn't as strong as it could possibly though it was strong enough to keep their secrets relatively private. The senders of the messages that used the DES were generally angry that they couldn't have more secure encryption that had been created already, but the NSA was justified in keeping the security of the DES at a lower level the possible. In doing this, the NSA made it more difficult more threats against the US to develop within the US, which is the biggest threat to the security. While foreign attacks on the US are a more likely possibility, it is the home grown attacks that prove the most dangerous because security within the US is relatively weak in comparison to the security of getting into the US. Home grown attacks also more difficult to detect because there are a larger number of people that could be in on a plot and the members of a plot might be more diverse and harder to track. The solution to home grown attacks would be to either make it easier to identify attackers or make attackers jobs more difficult by increasing security; increasing security would first of all be a logistical nightmare because of the size of the US and secondly it would also cause mass protests amongst the US population who already despise the relatively simple security measures of airport security. Because of that, the NSA had to go with solution b and make it easier to identify attackers by making their communications open to the NSA if they ever become suspicious, while allowing the NSA to focus more time on investigating foreign communications.

Image: "Elderly Armenian Woman Guards Home" by United Nations Photos, Flickr(CC)

Illegal Knowledge

In Cory Doctorow's Little Brother, Doctorow discusses the different types of cryptography without going to deep into the math behind it, instead focusing on its modern history and its effect on modern society. In the beginning of chapter 17, Doctorow briefly talks about the recent state of cryptography being considered a munition  and those illegal to create, instead everyone that needed cryptography had to rely on what was given to them by the NSA, even though that cipher was purposely designed to be possible to crack. This meant that banks and corporations all had to use a cipher that was designed to fail, which meant that there secrets could be revealed by anyone as intelligent or with the same training as the NSA agents. The fact that the NSA created a ban on cryptography, which at first makes some sense, is simply  unbelievable because it means that like Marcus Yallow says, "[we] used to have illegal math." This made the passage capture my attention because it connects the over arching theme of what freedoms and rights do we have and ties it with something that we are discussing in class. The length at which the NSA went to block the publishing of a graduate student's paper just because it had a tutorial that had the potential to make a cipher thousands of times stronger then the NSA standard is aggravating because it seems that the NSA would be happier that there was a stronger cipher that they could use, but instead they tried to force everyone to use what they could control even if it made everyone's ciphers weaker because of that. The other aspect of this passage that appealed to me was the  fact that is was another example in Little Brother in which the governtment tried to control something because they believed that they knew what was best for everyone, even when it is plain to see that they were hopelessly wrong.

Image: Shotgun Cartridges by John Gilchrist


The Allure of Money and Fame

The main reason that I believe people still pursuing Beale's treasure because of the obvious reasons:fame and fortune. The allure of millions of dollars worth of gold laying around somewhere in Virginia is just too strong a temptation for most people to ignore, and those with the means and drive to actively search for it are going to because for most people, the outcome of finding the treasure is worth the effort. In addition to the monetary value of the treasure, claiming the Beale Treasure would result in fame across the country, the person that solved it would hailed as a modern Benjamin Gates (National Treasure, Nicholas Cage). The temptation of these two strong drive forces are powerful enough to get many people started, and the sensation that they are on the verge of discovering the treasure, much like the sensations a gambler feels when he hits a rough patch in his betting, is what keeps them at it.

The Great Decipherment

The Great Cipher, invented by the Rossignol family, was such a difficult cipher to crack because of two important factors. First the details and use of it was lost one the Rossignols died, which meant hat cryptanalyst had to start from scratch without knowing anything about how the cipher was created besides what they assume based on what other ciphers looked like during the same time period as Louis XIV.  The other significant factor that made the Great Cipher so powerful is the fact that it was not a simple single letter substitution cipher but actually a double letter substitution with a twist: instead of substituting letters, it instead substituted syllables. This greatly complicated the cipher because there an incredibly large number of ways in which to rearrange and cipher syllables, and if there is now starting point at which to begin deciphering the Great Cipher, then it becomes infinitely harder to crack the Great Cipher as opposed to a simple single letter substitution cipher. While these things combine to make it difficult to crack the Great Cipher; the inclusion of traps, such as numbers to delete the previous syllables, made it difficult to tell whether or not a postulated key to the cipher is correct until the traps are detected and accounted for. The combination of having no information about the formation of the Great Cipher as well as the unique substitution it uses as well as traps to trick cryptanalysts all combined to make it unbroken for 200 years after it was created despite the effort of many intelligent cryptologists.

The Advancement of Civilization's Effect on Cryptography

The reason that relatively untrained cryptanalysts are able to use frequency "on their own" is because the civilization has advanced enough for them to think in a way that allows for them to  think in complex ways. Though they are relatively untrained in the discipline of cryptography, they are well versed in the realm of linguistics, both reading and writing, and as well as at least a basic understanding of math and statistics.  This is very different from the civilizations that Singh refers to when discussing civilizations that weren't advanced enough to to preform crypt analysis, in those civilizations writing, reading, math and statistics were reserved to such a select few that new and original ideas were hard introduce. Because there were no new ideas that came into the intellectual aspect of the civilizations and the intellectual community is so small, it is hard for people to notice the patterns that is the basis of frequency analysis. In today's society, even those that are classified as "amateur" cryptanalysts still have a solid base in linguistics and at least a basis in math and statistics which allows them to be able to come up with frequency analysis "on their own."   The intellectual community is larger and because of that , there are more examples of cryptography and as Singh shows in his book, the more material there is, the easier it is to see the pattern of the encryption that hides the plain text of a message. The intellectual basis combines with the fact that the intellectual community is larger in order to create the opportunity for frequency analysis to appear naturally in today's society, as opposed to the civilization, such as Europe, who Singh classifies as not having "sufficiently sophisticated level of scholarship ".

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