Sunday, May 13, 2018

Another correction

After the release of TICOM report D-83, in The British Typex cipher machine I’ve changed the paragraph

In the period 1940-41 the cipher research department of the German Army’s signal intelligence agency Inspectorate 7/VI had several talented mathematicians (Pietsch, Steinberg, Marquart, SchulzRinow) tasked with examining difficult foreign cryptosystems. The war diary of Inspectorate 7/VI shows that these individuals investigated the Typex device and by May ’41 had ascertained that it was mainly used by the RAF and was issued with 10 rotors. Their research on its internal cipher operation however was slow and had not led to any breakthrough. Things changed in May when they visited the facilities of the Signal Intelligence Agency of the Supreme Command of the Armed Forces - OKW/Chi and were able to examine a Typex machine captured at Dunkirk. The device worked according to the Enigma principle with the two rotors on the left remaining stationary and the wiring of the entry and reflector wheels could be recovered’  

into

In the period 1940-41 the cipher research department of the German Army’s signal intelligence agency Inspectorate 7/VI had several talented mathematicians (Pietsch, Steinberg, Marquart, SchulzRinow) tasked with examining difficult foreign cryptosystems. The war diary of Inspectorate 7/VI shows that these individuals investigated the Typex device and by May ’41 had ascertained that it was an Enigma type device with 5 multistep rotors, the last two of which did not move during encipherment. Their research was confirmed in May, when they visited the facilities  of the Signal Intelligence Agency of the Supreme Command of the Armed Forces - OKW/Chi and were able to examine a Typex machine captured at Dunkirk. The device worked according to the Enigma principle with the two rotors on the left remaining stationary and the wiring of the entry and reflector wheels could be recovered’.