The Research Corner |
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The Research Corner is Web page that shows some of my cryptological research interests but it is also a place where I will inform the public about cryptological topics that might be of a more general interest. I often come across bits and pieces of information that do not easily tie in with my other publication efforts. It would be wrong of me to sit on this information forever and not using it so when time allows I will try to put up some of this information here.
The Typex files are documents from the US Naval cryptanalytical organisation OP-20-G's study of the British cipher machine Typex. At the end of the war, OP-20-G got access to one of these machines that were used operationally by the British Navy in the Atlantic Ocean area. At the same time, they also had access to the operational rotor sets used with this machine, SP02390, SP02391 and Y269. The documents contain the rotor wirings, photos of a Typex Mark II, serial No. 2026, and other technical details such as circuit diagrams, movement patterns, indicators etc.
The Schlüsselfernschreibmaschine (SFM) T43 is a German Baudot one-time tape mixer of the Vernam type that was developed in 1943 and that was brought into service on some teleprinter communication links towards the end of 1944. It saw use mainly on links carrying especially secret or sensitive traffic. According to Dr. Werner Liebknecht of Wa. Prüf 7/III (Heereswaffenamt, Waffenprüfung, Abteilung 7, Gruppe III – Army Ordnance, Development and Testing Group, Signal Branch) the machine was originally developed by Obstlt. Schultze-Köther for the German Air Force (Luftwaffe). An extract of this testimony from his interrogation report TICOM I-57 is available here.
Dr. Erich Hüttenhain and Dr. Walther Fricke of OKW/Chi have given a more technical description of the machine and they describe a security problem that was discovered during the development of the machine. This problem was due the key relays being too slow and therefore the plaintext and key impulse to be added would arrive slightly out of phase. By studying the ciphertext impulses at the line output one could derive information about the plaintext and key impulses. An extract from their background papers compiled into TICOM report I-45 is available here. For those who are interested I have also decided to make the complete compilation available:
TICOM I-45: OKW/Chi Cryptanalytic Research on Enigma, Hagelin and Cipher Teleprinter Machines
by Dr. Erich Hüttenhain and Dr. Walther Fricke of OKW/Chi.
Copyright:
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The material described on these pages is created, collected, edited and published
by Frode Weierud, © February 2016
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