Otto Buggisch
Otto Buggisch was a German mathematician who, during World War II, was a cryptanalyst working in the cipher bureau, the Cipher Department of the High Command of the Wehrmacht responsible for deciphering of the opposing forces Communications. He also dealt with the security control of own key procedures. Through research and revelations exposed by two Polish officers, late in the war, he recognized the true cryptographic weaknesses of the Enigma rotor cipher, key machine used by the German armed forces to encrypt their secret communications, in World War II.
Life
Buggisch graduated from the Ludwig-Georgs Gymnasium in Darmstadt in 1928. He studied pure mathematics and physics and the subsidiary subject applied mathematics at the Technische Universität Darmstadt.In 1938, Buggisch was promoted to Dr. rer. nat. with a mathematical dissertation titled On the Rarity of Equations with Affect which was supervised by Udo Wegner at the Technische Universität Darmstadt.
During the war, Buggisch held the military rank of a sergeant in group 7/VI at OKW/Chi.
Military career
1940
From May 1940 to July 40, Buggisch was posted to a Wireless Telegraphy Listening Interpretation Station of Army Group C in Bad Schwalbach, Bad Kreuznach, Saarbrücken. Buggisch was subordinated to Hauptmann Walter Mettig, a signals officer, who became second-in-command of OKW/Chi. Together with his colleague, the mathematician, Wolfgang Franz, they initially worked on French Army cipher systems before and during the Battle of France. These were the F90, F110 ciphers, known by their German designations and were based on 4-figure codes. In one case the recipher consisted of a periodic adder, or subtractor of length 11. In the other, it was ordinary transposition, the transposition key being obtained from a key word which itself was taken from the code and shown by an indicator group. Both systems were being read from the winter of 1939 to the end of the Battle of France in June 1940. Buggisch also worked on analysing the diagonal write-out transposition, C-36 cipher machine These were simple field codes. From 20 July 1940, he was posted and attached to an intercept station in Berlin at 29/30 Bendlerstrasse, where there were other specialist sections for interception of Russian and Balkan traffic. During this period, he undertook the completion of two works on the C-36 Cipher machine, while working with the team which included Erich Hüttenhain, the chief cryptanalyst of OKW/Chi and Fritz Menzer, the hand and machine cipher designer and inventor. Buggisch also studied the M40 device, designed by Fritz Menzer, finding it moderately secure but it was never actually used. The M40 device was the forerunner of the Cipher Machine 41, but the motion of the wheels was found to be not so irregular.During September 1940, Buggisch was transferred to a Soviet specialist section. They worked on a 4-figure code and 5-figure codes, creating practice messages. In October or November 1940, Buggisch transferred to an intercept station in France.
1941
In January 1941, he was transferred to the Balkans specialist section that was directed by Rudolf Bailovic. Buggisch worked on the Greek 5-figure transposition cipher. Two memoranda were issued concerning the JUGO – SLAV code.Around 1 February 1941, all cryptanlysts including Buggisch were transferred from the Intercept station to the Inspectorate 7 unit, later called the General der Nachrichtenaufklärung.
In June 1941, Buggisch moved to the newly formed Signals Recce Abteilung, with all personnel who worked in In 7/VI being subordinated into that unit. The Russian cipher specialist section was again subordinated to the Intercept station, with the unit moving to Loetzen. Between July 1941 and November 1941, while at Loetzen, Buggisch worked on 5-figure material, specifically the OK40 code and the K37 machine. The OK40 was the official Russian designation for the Soviet 5/F or 5-figure operational code. It contained 25,000 groups namely all the five-figure numbers and only these, in which the first three figures were all simultaneously odd or simultaneously even. For recyphering the add or 300 5/F groups were in general use by the Soviets. The code was used from about the end of June 1941 to September 1941, by the higher and highest Soviet Army command. Soon after the beginning of Operation Barbarossa, several copies of the code were captured along with their recypher tables but with most of them out of date by that point, with the Soviets changing them frequently, but not yet daily. Owing to the already mentioned special characteristic of the first three elements of the code groups it was particularly easy to line them up. In this way, depth of 8–12 was often obtained, so that the recipher could easily be stripped by well known methods.
The K37 was the Russian Crystal cipher machine, that worked on the same principle as the B211 cipher, but a more primitive cipher. The K37 machine was different from the B211 in lacking the or, a sort of Enigma wheel by which the path of the current was turned to another channel at one point, crossing over and exchanging positions with another path instead of continuing parallel. Buggisch called this the X effect, and stated it greatly complicated cryptanalysis, as it was hard to tell when it was being employed in place of the parallels.
A model was captured in 1941. Analysis by Buggisch and Herbert von Denffer found that it could be solved on a 10 letter crib. The work remained purely theoretical as no traffic from this machine was ever received.
In November 1941, Buggisch was transferred to In 7/VI in Berlin, working at the French specialist section, located at Matthekirchplatz 4. Posted there until August 1942, he worked on a variety of problems, including
The unit included Dr Kunze of Pers Z S, working on French diagonal write-out transposition ciphers used by the de Gaulle delegation in Senegal.
1942
At the beginning of 1942, Buggisch's signals unit was disbanded and he was transferred to a company called 4 Company, Evaluation Company was formed with Major Mettig in command In the summer of 1942, Buggisch was working with Doering on the first detailed investigation of cypher teleprinters, the T52 models T52a to c, that were to be extensively used by the Wehrmacht. The B211 code was worked on with Denffer and Hilburg later in the summer. Buggisch worked in the section until August 1942, until a reorganization of the specialist desks of Section VI was undertaken. A few mathematicians left for Section IV of Inspectorate 7. Buggisch transferred to the newly formed cipher machine specialists section, conducting extensive investigations into Cipher Machine 41. Buggisch subsequently worked on call sign's and research into the double Playfair. In November 1942, Buggisch started work into research of Cipher Machine 39 that was being proposed for use by the Kriegsmarine.By the summer of 1942, Buggisch had been assigned to work full-time on the cypher teleprinter T52 with Doering. Buggisch and Doering worked on versions a, b, c of the teleprinter, as well as the SZ40 rotor stream cipher machine. The B-211 code was studied in detail, using traffic collected from two years before. A theoretical solution to the B211 code was developed by the group and back traffic was actually solved. However, the method did not work in practice when B211 traffic was again encountered. Buggisch did not mention any other solutions.
In August 1942, Inspectorate 7/VI were again under reorganization. Buggisch was transferred to the newly formed machine specialist section. Buggisch conducted an investigation into Cypher Device 41 known as Schlüsselgerät 41. Buggisch stated that Device 41 was Fritz Menzer's idea, and the technical side was worked on by Wa Pruef 7/IV. Buggisch also worked on Call signs and weaknesses in the double Playfair cipher. In November 1942, Buggisch began research into the security of the naval version of Cypher Device 41.
1943
In the spring 1943, Buggisch conducted general investigations into the small technique TECHNIK Hagelin machine. The Swedish firm, A.B. Cryptograph, Stockholm produced an early type of Hagelin machine known as TEKNIK. One example of the BC 38 device was received from the Wa Pruef 7/IV unit, together with the statement that Boris Hagelin was working in America. The BC38 was a Swedish Hagelin machine. An engineer called Voss, who was a German spy in Sweden, had informed Germany that the US was planning to adopt a Hagelin idea. Buggisch and his team had investigated the Hagelin machine for security weaknesses. Buggisch also conducted research into Enigma machine 39 during this period. He also started work on a future German Standard Cypher teleprinter standard. French C36 messages appeared in the 5-figure Charles de Gaulle code traffic again, with the decoding of the work being done by means of the method developed earlier by Denffer. It was discovered to be transposed. Likewise more B-211 messages appeared but the theoretically worked out procedure did not result in a decode.During the summer of 1943, Buggisch works with Luzius and Rudolf Kochendörffer on the Crib problem with converter 209, which had been captured from Italy. This was the first key recovery from a crib. Major Lechner was head of Section Inspectorate 7/VI. During this period Buggisch conducted conferences with OKW/Chi regarding security studies on the BC38 device, which was the Swedish Hagelin cipher machine, on the Enigma cipher machine and on the cypher teleprinter with Karl Stein and with Gisbert Hasenjaeger. During the summer Buggisch worked on and broke the Croatian Enigma. From about August 1943, Buggisch worked on a captured specimen of converter 209 from Italy. During the course of 1943, the Inspectorate 7/VI was renamed to the Signal Intelligence Section of the Department of signals of the General Army Office. In October 1943, the office moved to Jüterbog. In the winter of 1943, Buggisch worked with Doering, whose specialty was also machine ciphers, on Russian cypher teleprinters, i.e. the Russian Fish device, cribs and supposed results of the device from the Forschungsamt. He also worked on the Enigma specifically crib problems, Bigram systems. On the Converted 209, he worked on column separation. He also conducted continued research on the C36 messages, looking at messages with complicated enciphering techniques, which were solved in the spring. Later, he conducted lectures on theory, specifically discussing depth problems, X2 and W2 methods.
Towards the end of the year, in November 1943, Buggisch had a discussion with Korvettenkapitän Jaeckle. He has become acquainted with Jaeckle in 1943, when Jaeckle who was an ordinary Naval Signals Officer, had managed to get hold of a model of the M-209 cipher device and had worked out a solution while sitting idle in a French port. The solution was, in fact, childish and consisted of nothing more than a study of the theoretical working equation of the machine. Jaeckle had talked his way into the SKL and had talked a lot about getting a section of 200 men to work on the machine. Actually he had been exposed quickly and had been sent back to sea after three or four months. Buggisch considered this a very foolish incident altogether.