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 Hatted diplomatic 5-figure codes used by Charles de Gaulle Swiss Hagelin machine messages. 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,