I think I have earlier touched the subject of cryptology and deciphering. A well-known example is how the British in Bletchley Park, with important ground- work being done previously by the Poles, mangaged to break into most of the German Enigma ciphers during World War II. In this they had the help of early number-crunching machines such as the "Bombes" and particulary the Colossus, the first electronic computer in the world, constructed by among others the famous Alan Turing. It may be less well-known, but the fact is that the Swedish intelligence service during WWII had their own successes with German ciphers. With the fundamentals worked out by the brilliant professor in mathematics, Arne Beurling (1905-1986), they broke into the German Geheimschreiber, a machine used for teletype traffic and by many considered even more complex than the Enigma. Bengt Backman's book Svenska kryptobedrifter (Bonniers, 1996) tells all about it. The title means "Swedish Crypto Achievements", and the book has also been published under that in English (so you may be able to find it). The Enigma was a machine the Germans used for wireless traffic (in fact there were several Enigma designs, with eg a different number of enciphering rotors; so there were numerous different Enigma ciphers) issued to all the German WWII armed services in huge numbers (one source says 200 000 Enigmas were produced). The Geheimschreiber ("Secret Writer") or G-schreiber was a machine used for wire traffic. They were not similar in design; the Enigma used revolving rotors to garble the text. The G-schreiber on the other hand used a complicated set of relays; the Enigma was intended for morse code and produced ordinary letters in the form of lamps lighting up on a panel; the G-schriber used binary teletype code. The G-schriber was probably the most complicated of the two, being the size of desk, weighing hundreds of kilos; the Enigma was like a medium-sized protable typewriter. The G-schreiber was also considered to be safer and was issued in far less numbers. The Swedes had a history in cryptology. One of the first cipher machines in the world was constructed by the baron Gripenstierna and presented in a letter to king Gustaf III in 1786 (consisting of a large drum with movable rings of letters). Around the time of WWI a Swedish engineer, A Damm, began designing a cipher machines, later in the early 20's perfected with the help of B Hagelin and soon to be available on the commercial market as the Hagelin machine. The Hagelin was in fact more or less the blueprint for machines like the Enigma and was in different variations used in WWII by both the British, Americans, Swedish, Italians, Japanese and many other militaries. (With internal modifications of the wiring and such, though the principles of operation were the same.) In the 1930s the Swedish military became very interested in cryptology and opened cipher-schools. One who took part in this was the young, then national serviceman, Arne Beurling, who was able to prove that the then used Swedish Army cipher machine had built in weaknesses. At the same time the Swedish intelligence had some success with eg breaking into the Soviet navy ciphers. The activities were intensified as WWII came closer and eventually broke out, a war the Sweden stayed out of as being neutral - and was hoping to continue to stay out of! For this policy, the deciphering by the intelligence service became absolutely crucial. As Germany invaded Denmark and Norway, April 9th 1940, Sweden became surrounded (Finland to the east had an uncertain peace with the Soviets, for a short time) and her military forces were far from adequate to deter an aggressor. The Germans who soon after also took most of Western Europe were at the height of their might and could bully the Swedish government to some concessions, including continued delivery of the valuable iron ore, transit by train of soldiers on leave, and the right to use Swedish telegraph lines. The last thing proved to be a lucky thing - for the Swedes. Of course the Swedish intelligemce service tapped the lines, despite that the texts to begin with looked like gibberish. Beurling who had done his military service in the cipher school had meanwhile become professor of mathematics at Uppsala Unversity. He called the military himself, and suggested that he should be drafted - into the cipher department. He was. The Defence Staff crypto department was originally housed in a building in central Stockholm, on Karlaplan No 4, which soon became known as "Karlbo". It was originally one big, ordinary flat (which said "Jacobsson" on the door), but as the activities grew the department annexed more and more of the surrounding flats. It would eventually grow to a department of 500 or even more, which would later move out of central Stockholm. Security was very strict. None were allowed to talk about their work, only say they did administrative work for the Defence Staff. (But this security wasn't airtight, as we shall see later.) Decrypted messages were distributed on a very limited scale, and had to be burned after being read. What Beurling did, was practically the same as Turing & Co did in Bletchely Park, about the same time, but with a different cipher machine. But Beurling didn't have "Bombes" and early electronic number-crunchers to help him. He simply ordered to get the print-outs of all G-schreiber traffic for a certain day (May 25th 1940), and then looked himself into a room, with paper and pencils, for a fortnight. And then he emerged and said "Iv'e got it!". No one is really sure *how* Beurling did it, but this book has an attempt to reconstruct his reasoning. He never left more than tiny clues to how he worked, and explained "A magician never reveals his tricks!". What we do know is that he could break in with the help of lapses in the crypto discipline, that overworked or even right out sloppy operators allowed themselves. (It was the same with the Enigma. Lapses in routines were always the cracks that let the Bletchley people in.) Before I continue with Beurling, the Swedes had several other very talented crypto analysts too. The Russian navy ciphers have been mentioned. One Yles Gyldén broke into the French diplomatic ciphers. Several other ciphers were also successfully attacked, but AFAIK not anything Enigma based. It seems the Swedes never gave priority to Enigma; they had the land lines to tap and Enigma was for the wireless. The Swedish talent for SIGINT (SIGnal INTelligence) have lead to many cases of intelligence cooperation with the "West", something that has continued until today. In the 1950s a Swedish SIGINT DC3 was shot down by the Soviets over the Baltic Sea, filled with American listening equipment (the info the Swedish military got was obviously going to be shared with the Americans; however the DC3 mission was "legal" and over international waters!). From June 1940 until May 1943, the Swedes could read all or substantial parts of the German military cable traffic that went through Sweden, ie traffic to and from Finland and Norway. It was 10 000's of telegrams, and many would contain general assessments of the military situation and dispositions in the whole European theatre. So the Swedish military intelligence got a front row seat to the German military capacity. They would know when a threat was real or when it was just a diplomatic bluff, and of course so would the government which could issue orders of partial mobilisations, movement of troops, etc to adapt. On several occasions, there were partial mobilisations to counter possible German threats (the "midsummer crisis" of 1941 around the time of operation Barbarossa, an invasion threat of February 1942, and of course August 1943 when the Swedes cancelled the German use of Swedish railways). The Defence Staff crypto department may not be the sole reason for Sweden being able to stay out of the war, but it certainly did a very substantial contribution towards it! Despite top secrecy, a spy crept into the crypto department. A courier by the name Allan Emanuel Nyblom who transported the deciphered documents from the crypto department to the Defence Staff was in January 1942 revealed as a spy for - the Soviets. He did it partly for ideological reasons, partly for money, and was only revealed after he had been involved in an affair of illegal abortions (in which a failed abortion lead to a woman's death). This didn't hurt the Swedes capacity to read German telegrams (but the Russians tightened their own cipher security) since they had no reason to tip the Germans off - they were at war with Germany. However, another leak jeopardised the crypto department. Exact details has never been found out, but the leak probably came from the Finns - who were at war on the German side. The Finns learned that the Swedes seemed to know a lot about the Germans, and hinted that to them. This happened in mid-1942 and one possible leak is the Finnish military attache in Stockholm, one colonel Stewens, who often moved around in the Defence Staff HQ. He may even have seen decrypted German messages. But even after this, it would up to a year for the Germans to tighten up their security. They were slow in changing their routines, introduce new ciphers, and new cipher machines. They did in fact begin using a new modified G- schreiber, but it was easy to break into for the Swedes; a further new model was also broken into. Only a fourth, unknown cipher machine proved too much for the Swedes. At this time, it didn't matter too much, though. This was after El Alamein and Stalingrad, the German war machine had lost its edge. The threat against Sweden was substantially smaller. The crypto department had gotten us through the worst, when the info was crucial. How did Arne Beurling do his successful cipher attack on the G-schreiber? A "reconstruction" was done by one Car-Gösta Borelius, who himself worked with the G-schreiber material. It is known that Beurling ordered material from 25th of May 1940, when the lines had been established and worked well but before that operators had time to get used to them. Here are some details. One "code" the operators would use often was "QRV", international telepgraphese for "Do you read me?". Another thing was that the lines often had disturbances which for instance would lead the character table to "shift" to numbers (numbers were reached after a certain "shift" character). To counter this, the telegrams would often replace the character for "space" with the (non- printable) characters for "shift to alphabetical" followed by an extra "space". If the text was shifted to numbers, it would therefore automatically shift back to letters at every space position. The Swedes used their own "pseudo" coding for the silent (non-printable) characters, in which "shift to alphabetical" + "space" would print as "35". So Beurling would know that "QRV" would often come early in a message exchange, and that "space" would usually written as "35" (to to make sure that the tables didn't shift to numbers). Also, between enciphered messages the operators, who were "on-line" to each other", would produce quite a lot of chat which wasn't enciphered, to prepare for the enciphered text to be sent. This would give clues to what kind of messages one was to expect, eg: in clear "I begin to encipher now. Do you read?", probable answer (enciphered) "Yes, I can read". Another weak point was that when an operator had to resend a message, it was complicated to make a new setting for the G-schreiber, byt realatively easy to go back to the previous key. Operators would therefore often do this, which was a breach of standard procedures and made it easier to break into the traffic. Beurling discovered that the plain text of 3 and 5 had one pulse the same and four different (they were written as a binary with five binary pulses), this had also to be the case in the enciphered state. For a guessed 3 there existed only five possible 5 and vice versa. It was therefore easy to establish spaces between words. And a guessed 3 gave only five possible Q and V in QRV. Then he saw that a change from one character in the plain text to a cipher character after the "overlaying" (ie passing through the G-schreiber relays) consisted of a change in polarity for some of the pulses in the plain text character, and for all the characters in the column it was always the *same* character that changed. This could be analysed manually on big "work sheets". With clues like this, Beurling could begin to look for patterns that could reveal the inner wiring and layout of the G-schreiber. From his instructions, the telecom company L M Ericsson, designed functional equivalents to the G- schreiber, which became known as "Appar" ("Apps", from "apparatus"). Every morning the Swedish crypto department would go through the latest messages, and find out the keys (usually from messages resent in the same wording in several copies with different keys), which would then be handed over to the "Apps" and be deciphered, more or less in real time. It should be noted that the machines, both the G-schreiber and Enigma, probably gave perfectly adequate security, in a mathematical sense. It was sloppiness in procedures and with the operators that opened cracks that decryption attempts could put to use. It was an operation amazingly similar to Bletchley Park, which however was much bigger (10 000's of people involved), possibly because the volume of messages Bletchley handled was much bigger (and Britain was also in a shooting war). Beurling did his thing alone, though, not together in a whole team, and just with his brain - not with any number crunching machines. The author and crypto historian David Kahn wrote: "Quite possibly the finest feat of cryptanalysis performed during the Second World War was Arne Beurling's solution to the Secrect of the Geheimschreiber." Beurling would after the war be offered a position at Princeton, where he BTW had the same office as Albert Einstein. He did not - according to this book - became more than moderately successful, the reason being that he interested himself in rather obscure fields of mathematics that didn't attract much attention. The Defence Staff's crypto department was in 1942 turned into The Defence Radio Institution (or in Swedish Försvarets Radio-Anstalt, abbr FRA), which is an organisation that lately has become the subject of a heated debate. FRA has for a long time, probably not without success, been snapping up all kinds of signals and traffic going through the ether. In later years, however, much of the traffic that used to go through the air or via satellites, has move to cables. So the Swedish parliament in the beginning of the summer passed the *highly*controversial so called FRA Act, with empowered the FRA to scan *all* cable traffic going out of, into or across Sweden for "outer threats". (There is little doubt that they hope to catch a lot of Russian traffic.) However, this means they would also "scan" all innocent Internet traffic to and from ordinary citizens. It is basically a Swedish version of Echelon (if you have heard that name before). Quite often ordinary traffic from ordinary citizens "bounces" through a foreign server, or goes across a border due to technical reasons. One can never know when FRA will be listening. People in general have been outraged by this FRA Act, which is seen by many in the public debate as a threat to personal integrity. There has been lots of protests and the government has (mosly in vain) tried to defend itself. The debate has not died down. There have been street demonstrations. There are articles about it in the papers every day. The so called "blogosphere" has attacked the FRA Act in a massive manner. The question will be up in the parliament again this fall. And, strangely enough, it all started with breaking into German messages during World War Two. --Ahrvid More information: The Geheimschreiber Secret - Arne Beurling and the success of Swedish signals intelligence: http://frode.home.cern.ch/frode/ulfving/ulfving.html About the Geheimschreiber: http://july.fixedreference.org/en/20040724/wikipedia/Geheimfernschreiber About Arne Beurling: http://wapedia.mobi/en/Arne_Beurling The Geheimschreiber Secret (a very good article!): http://web.usna.navy.mil/~wdj/papers/cryptoday/ulfving_weierud_secret.pdf ----- SKRIVA - sf, fantasy och skräck * Äldsta svenska skrivarlistan grundad 1997 * Info http://www.skriva.bravewriting.com eller skriva- request@xxxxxxxxxxxxx för listkommandon (ex subject: subscribe).