Two of the most important systems were the ciphers used by the operational troops of the NKVD for communications from Regiment upwards.From German reports it is possible to identify their original designation and the one given to them by the Germans. According to Alexis Dettmann, head of cryptanalysis at the German Army’s cryptanalytic centre in the East Intercept Control Station East - HLS Ost the high level systems were:
These enciphered codes were used on the links GUP NKVD-Front staff-Division-Brigade-Regiment.A monthly report of Inspectorate 7/VI says that the main cipher system of the security and operational troops of the NKVD (Sicherungs u operative Truppen NKWD) had the original designation 039W and the German designation was R4 ZC 1100 (4 figure code with additive encipherment).
The replacement was 049W, introduced in September 1944 (with the exception of the 4th Ukrainian front). The German designation was R4 ZC 2750. This code was enciphered twice with numerical sequences. Despite this fact it was possible to solve messages due to mistakes in encipherment and stereotyped beginnings.
This information complements and supports the validity of TICOM report DF-112, written by Dettmann.