() was the signals intelligence agency of the Heer (German Army), before and during World War II. It was the successor to the former cipher bureau known as Inspectorate 7/VI in operation between 1940 and 1942, when it was further reorganised into the Headquarters for Signal Intelligence () () between 1942 and 1944, until it was finally reorganised in October 1944 into the GdNA. The agency was also known at the OKH/Gend Na, GendNa or Inspectorate 7 or more commonly OKH/GdNA. Inspectorate 7/VI was also known as In 7 or In/7 or In 7/VI and also OKH/Chi.
Chi-Stelle The letter Chi for the ('cipher department') is, contrary to what one might expect, not the Greek letter Chi, nor anything to do with the chi-squared test, a common cryptographic test used as part of deciphering of enciphered message, and invented by Solomon Kullback, but simply the first three letters of the word .
Key personnel
Senior personnel Erich Fellgiebel, was Director of the Code and Cipher section of the Defense Ministry from 1931 to 1932 and held the dual combined office of Chef HNW and Chief Signal Officer Armed Forces (Chef WNF) from 1939 until 20 July 1944. Fellgiebel was executed in July 1944 after an attempt on Hitler's life in the failed 20th July plot.
The unit was then subordinated to Fritz Thiele, who was Director of Section III of the Armed Forces Signal Communication Group, Radio Defense Corps, or more accurately the AgWBNV, Radio Communication Group 3 (), (AgWNV/FU III) were responsible for locating, eliminating, or neutralizing all enemy agents' radio activities.IF-176, foreword
Wilhelm Gimmler, () was Chief Signals Officer subordinated to Commander in Chief OB West and Chief of the Armed Forces Signal Communications Office. Gimmler was responsible for coordinating all the cryptographic security studies undertaken by German Armed Forces and was notable for standardising wireless phraseology between different Army Groups.
Colonel Hugo Kettler was a career Signals officer, who volunteered at the start of World War I, entering the Telephone Replacement Department No. 6 () and after undergoing continual promotion during World War I and the interwar period, was a senior signals officer at the start of World War II. Colonel Hugo Kettler was a Director of OKW/Chi from October 1943. Kettler was first director of HLS Ost and who would later become Chief of OKW/Chi in the summer of 1943. During the summer of 1942, Kettler was succeeded by Baron Colonel Rudolf Von Der Osten-Sacken, who remained its chief until July 1944, when he was implicated in the 20 July plot on Hitler's life and committed suicide before he was scheduled to be hanged.
Headquarters
Agn/Gen. der. Nachr. Aufkl – Fritz Boetzel Chief of Staff () – Andrea Adjutant Norawec Chief of Understaff () Köbe Group Z – Major Hüther
Fritz Boetzel, was the officer who was responsible for the German Defense Ministry's signals intelligence agency, during the important interwar period, when the service was being enlarged and professionalised, In 1939, he was posted to Army Group Southeast () to take up the office position of Chief of Intelligence Evaluation in Athens, Greece. In 1944, following the reorganisation of the Wehrmacht signals intelligence capability, Fritz Boetzel, now General Fritz Boetzel, who was promoted by Albert Praun, created 12 Communications Reconnaissance Battalions (KONA regiment) in eight regiments, with each regiment assigned to a particular Army Group. Fritz Boetzel was considered to be one of the sources for the Lucy spy ring. Boetzel knew Hans Oster and Wilhelm Canaris and had fit the anti-nazi personality of Rudolf Roessler contacts, the man who had run the spy ring.
Cryptanalysis unit command
The directors of the In 7/Vi cryptanalysis units from January 1941 to February 1945 were:
Major Major Mang. 1941–1942 Major Mettig. November 1941 to June 1943 Major Lechner 1943 Major Dr Rudolf Hentze 1944–1945
Werner Mettig was a career signals officer who joined the military in 1933, and worked up to command the Germany Armies cryptologic centre, Inspectorate 7/VI from November 1941 to June 1943. After working in the Signals Battalion on the Eastern Front for several months, he was assigned second in command of OKW/Chi in December 1943, and subordinated to Hugo Kettler, and held the position until April 1945. After the war he was considered such a high-value target that he was moved to England to be interrogated by TICOM.
Communication office The following German army officers worked with the communication office and provided the main liaison function for conveying intelligence from the central office to the field.
Unit Commander Johannes Marquart and I/C Cryptanalysis Leutnant Schlemmer were commander of KONA 5 and were communication intelligence liaison officers for several army groups on the southern part of the Western Front.
Unit Commander Major Lechner and I/C Cryptanalysis Leutnant Herbert von Denffer were commander of KONA 6 and were communication intelligence liaison officers for several army groups for the northern part of the Western Front.
Colonel Walter Kopp, was a senior communication intelligence officer for OB West, i.e. for Sig. Int. West.
Gotthard Heinrici was on the General Staff and chief signals officer for OB West.
Leo Hepp was a member of the General Staff and was deputy chief of army signal communication. Hepp was later chief of staff for the chief signals officer at the Oberkommando der Wehrmacht and directly subordinated to Fellgiebel and later General Albert Praun, when Fellgiebel was killed.
Colonel Muegge was a communication intelligence officer for an army group.
Colonel Kunibert Randewig was commander of intercept units with various army groups. Randewig was a career Signals officer, who joined the German Army in 1914. During the World War I and the interwar period, he became a veteran of monitoring Soviet wireless communications and a supporter of decentralisation of signal intelligence. He would eventually become Commander of all KONA Signal Intelligence regiments in the west. Randewig would later work on the rocket programme.
Cryptanalytic staff
Johannes Marquart. He was a mathematician, who was also a German Army hand cryptographic systems specialist. In a later role, he was the liaison officer between the clearing centre of communications intelligence, and the Western Intelligence Branch, Army General Staff.
History
1919–1933
Little was known about the Signals Intelligence of the German Army during this period. A Codes and Ciphers Section of the German Defence Ministry () was subordinated to an Army Signal Officer, that had been maintained in skeleton form since the end of World War I. The following people were directors of the unit:
Lieutenant Erich Buschenhagen 1919–1927 Major Rudolf Schmidt 1927–1931 Major Erich Fellgiebel 1931–1932 Major Hans Oschmann 1932–1934 Major Fritz Boetzel 1934–1939
The directors of the ciphers section also controlled the Defense Ministry's intercept network, which was used to gather operational intelligence and was divided into two branches. The first branch was the fixed intercept network stations which were dated from 1923 to 1924 () (Feste), and at least seven stations were operating before 1933 in military districts. The second intercept branch was the motorised Intercept Companies (), created by Fellgiebel himself. Six of the stationary intercept stations were aligned specifically to the interception of foreign military traffic and the last one specifically designed for foreign diplomatic traffic. The military traffic stations were: Stuttgart, Munich, Münster, Königsberg, Leignitz and Breslau with the diplomatic traffic intercept station located at Treuenbrietzen. Each intercept station was assigned a series of intercept assignments, with the most important assignments monitored by two stations, e.g. the Soviet Union was monitored from Königsberg and Frankfurt, and so on. The assignments were established in the Assignment Plan H-Aufgabenplan. Each assignment was prioritised from first to fourth, sometimes absolute, sometimes relative, e.g. Poland was assigned first for Frankfurt/Oder stations and a first or second for Königsberg. Priority could change depending if a country went to war.
1933–1939 During the 1933–1934 period, the Defense Ministry created three more intercept stations: one was at Hersbruck, (that was later moved to Lauf) with the other two located at Striegau and Chemnitz. Using the ten intercept stations to intercept foreign military and diplomatic communications, the Defense Ministry created its own military code and cipher section, called Intercept Control Station (HLS) () in 1933/34. To run the control station, the Ministry reassigned several trained cryptanalysts from the Ministry of the Reichswehr Codes and Cipher Section. All Army intercepts were forwarded to the HLS, but other intercept traffic types were forwarded to the commander-in-chief aligned agency, e.g. foreign Air Force traffic was sent to chi-stelle, the Luftwaffe Cipher Bureau. Diplomatic intercepts were sent to both German War Ministry () and to Foreign Office civilian cipher bureau AA/Pers Z S.
1939–1941
During the early years of World War II, substantial change occurred within the German Army signal intelligence service. The main developments were:
The intercept service mission was narrowed to include only Army Traffic. With the formation of OKW/Chi, the signals intelligence agency of the Supreme Command of the Armed Forces, in 1939, OKW/Chi took over all diplomatic intercept traffic. To help facilitate message interception, the Army transferred two interception stations at Lauf and Treuenbrietzen. The intercept service expanded. In 1939, the Army established two new branch stations for the intercept of foreign Army communications from the east. The branch stations were created as Graz and Tullin. Five new Signal Intelligence Regiments (, ) were created. The KONA operated in the theatre as complete intercept and evaluation units, while attached to Army Groups, (e.g. Army Group A). Each KONA unit was numbered from one to five. KONA units 1,2,3 were assigned to the Eastern Front. KONA 1 was assigned to the southern front, KONA 2 to the Central front and KONA 3 to the Army Group on the Northern Front. KONA 4 was not attached to any Army Group, but was subordinated to the commander of the German Armies in the Balkans ().IF-171 p. 1 KONA 5 was assigned to Army Group B on the Western Front.IF-127 In 1939, to cope with the increased demand and difficulty of decryption of enemy Army traffic, a large number of mathematicians and linguists, e.g. translators and interpreters were drafted and assigned to various field units, or intercept stations. When intercept units moved into the field in 1939, no cryptographers were available. Colonel () Kunibert Randewig, was a veteran of pre-war monitoring of Soviet Union wireless traffic. As commander of all the intercept units in the west, he was tasked with seeking available personnel. Those cryptographers which were available from Y Units around Berlin were reassigned with additional linguists and mathematicians recruited as necessary. As a result, when the German offensive started in April 1940, a sufficient group of cryptanalysts personnel was available.