The Pers Z S was the signals intelligence agency of the German Foreign Office (German: Auswärtiges Amt) before and during World War II. It consisted of two cryptologic sections. Pers Z S was the cryptanalytic section which was called Special Service of Z Branch of the Foreign Office Personnel Department (German: Sonderdienst des Referats Z in der Personalabteilung des Auswärtigen Amtes). Its mission was the solution of foreign diplomatic codes and ciphers. The other section, which was the Cryptography Section was called Personal Z Cipher Service of the Federal Foreign Office (German: Personal Z Chiffrierdienst des Auswärtigen Amtes) (abbr. Pers Z Chi). The latter section was responsible for compilation, distribution and security of Foreign Office codes and ciphers. Both were colloquially known as Pers Z S. Though similar in nature and operation to the OKW/Chi cipher bureau, it was a civilian operation as opposed to the military operation at OKW/Chi and focused primarily on diplomatic communications. According to TICOM interrogators it evinced an extraordinary degree of competence, primarily driven by a consistency of development not found in any other German signals bureau of the period. Pers Z S/Chi was the symbol and the code name of the Chiffrierdienst, i.e. the Cryptanalysis Department of Pers Z S. Although little is known about the organization, in the final analysis, Pers Z S labored at diplomatic cryptanalysis for a regime for which there were no diplomatic solutions.
Short name The abbreviation of "Chi" for the Chiffrierabteilung is, contrary to what one might expect, not the Greek letter Chi, nor anything to do with the chi test, a common cryptographic test used as part of deciphering an enciphered message, and invented by Solomon Kullback, but only to the first three letters of the word Chiffrierabteilung (English: cipher department).
History Little was known about Pers Z S before April 1945, when the first section was captured. TICOM (Target Intelligence Committee), the United States effort to capture German intelligence assets after the war, found that captured documents provided little information on the execution of the unit, with the records of the Mathematical and Cryptological section having been destroyed. The field covered by Pers Z S, over 25 countries for a period of 25 years, stymied the TICOM as few interrogators were available, and they also lacked experience in cryptographic diplomatic system. This was the first TICOM investigation. Inevitably there were some areas which were not covered. In May 1945, the usual approach by the TICOM was to force captured personnel to write "homework" describing processes used in a particular intelligence unit under interrogation, but this method was not fully developed. The only document prepared as "homework" was one dated 6 August 1945 by Professor Dr Hans Rohrbach, along with several of his Pers Z S colleagues, which described the cryptanalysis of the American O-2 strip cypher, which was considered a most significant piece of work.
1919–1937 The original name for Pers Z S was unknown but was likely from Political Intelligence Department, and was placed with Bureau I (Abteilung), the normal administrative department in a German government organization at the time. As the cryptography unit grew, it changed its name to Personnel Bureau It was later called Chiffrierabteilung, later still the Sonderdienst des Referats Z in der Personalabteilung des Auswärtigen Amtes. In 1925, it was known that both the cryptographic and cryptanalysis were unified under a single director. In 1919 Kurt Selchow had joined the organization and immediately started to professionalize the cipher bureau. He introduced a system of dividing work upon foreign codes and ciphers into sections for various countries and selected as leaders of these sections men such as Dr Pashke, Dr Kunze, Dr Schauffler who he had known during World War I. The strength of the organization during this period was unknown. In 1945 Dr Paschke and Dr Schauffler stated that between 20 and 30 people were employed in 1918. A May 1919 list shows 63 personnel employed, and would likely cover clerks, administrators, communications and liaison individuals. By 1930 the Pers Z S unit strength was around 50 personnel.
1937–1939 On November 1, 1937, Pers Z S had around 77 employees, and by July 1, 1938, this had decreased to 72 people. It was thought that the cryptanalysis unit had around 20 people. Under interrogation, Paschke and Kunze estimated that in 1939, Pers S Z personnel included between 80 and 100 people. A document captured on December 1, 1939, showed a total strength of 92 people, but another document stated that 45 new appointments were made between September 1, 1939, and November 1939. Thus it would seem reasonable to assume that at the start of the war Pers Z S had a personnel count of 50. The available documentation from 1937 to 1939 indicate that Z Branch suffered personnel shortages and a certain inertia within management. The job descriptions (German: Begruendungen) attached to the recommendation for promotion documentation detailed that Dr. Kunze was a Specialist (German: Regierungsrat) since 1923 and that Dr Paschke had held the same grade since 1927.
Positions with comparable activities and responsibilities in other ministries are given the grade of Principal Specialist (German: Ministerialrat) or Senior Specialist (German: Oberregierungsrat). This is spite of the fact that the personnel concerned are usually younger and have less time in grade.
Chi complained in 1938 that it could not function efficiently without additional personnel. Ten of its thirteen cryptographers were over fifty years old, six of them over sixty.
Due to the overloading of the cryptographic section, outgoing messages cannot be enciphered and checked with the necessary care. This regrettable state of affair was most noticeable during May 1938 and September 1938, when the political atmosphere was at its tensest.
The cipher bureau was organized as follows:
… excerpt ends here. Continue reading the full article.
