Walter Ernst Fricke | |
|---|---|
 Dr. Walter Fricke in 1968 | |
| Born | (1915-04-01)1 April 1915 Leimbach-Mansfeld nearMerseburg, Germany |
| Died | 21 March 1988(1988-03-21) (aged 72) |
| Citizenship | German |
| Education | Berlin University |
| Known for | Working as cryptanalyst with OKW/Chi,Fourth Fundamental Catalogue (FK4) |
| Awards | Prix Jules Janssen of theSociété astronomique de France in 1974. Dirk Brouwer Award of theAmerican Astronomical Society at theDivision on Dynamical Astronomy in 1982. Order of Merit of the Federal Republic of Germany (First Class) (German:Verdienstkreuz) of the Federal Republic of Germany in 1981 |
| Scientific career | |
| Thesis |
|
| Doctoral advisor | Otto Heckmann |
Walter Ernst Fricke (1 April 1915 – 21 March 1988) was a distinguished German professor oftheoretical astronomy at theUniversity of Heidelberg.[1] He was a mathematician andcryptanalyst duringWorld War II at theWehrmachtsignals intelligence agency, Inspectorate 7/VI from 1941 to 1942 (which would later become theGeneral der Nachrichtenaufklärung. In 1942 he was transferred to theOKW/Chi Section IIb. His specialty was the production of codes and ciphers, and the security studies of Army systems.[2] After the war he was director of theAstronomical Calculation Institute (German:Astronomisches Rechen-Institut) inHeidelberg,Germany.
Walter Fricke was born in Leimbach-Mansfeld nearMerseburg,Germany. His father was a carpenter who worked as a miner in the copper-schist mines atMansfeld. Walter Fricke attended a high school Stephaneum[3] inAschersleben and passed the final examination (Abitur) in 1934. After high school, he enrolled as a student atFrederick William University inEast Berlin, studyingastronomy,mathematics andphysics. His teachers there includedPaul ten Bruggencate andAugust Kopff in astronomy,Erhard Schmidt in mathematics andMax von Laue in physics.
In 1935, he published his first astronomy papers. These were critiques ofEdwin Hubble's studies made atMount Wilson Observatory on the distribution ofspiral nebulae.[2] In 1939, while resident at theGöttingen Observatory, he received his doctorate with a thesis titledInfluence of a resisting agent in the dynamics of dense stellar systems (Einfluß eines widerstehenden Mittels in der Dynamik dichter Sternsysteme). He obtained a scholarship to theUniversity of Edinburgh inScotland, which was arranged with the help of British theoreticalcosmologistDr George C. McVittie,[2] which was due to start on 1 October 1939[2]: 2 but had to be cancelled because of the start ofWorld War II in September 1939. On 1 May 1940 he started work atHamburg Observatory, and later in that year was drafted into the Signal Corps (Nachrichtentruppe). On 15 May 1941 he was posted toInspektorate 7, the cipher bureau of theWehrmacht (German Armed Forces) high command,[2] although as an astronomer he knew nothing aboutcryptography andcryptanalysis. ProfessorOtto Heckmann, director of the Hamburg Observatory, tried to lure him back to continue working on problems specifically related to war work that he had been occupied with before he was drafted: tables of air and ship navigation,aerodynamic problems foraeroplanes traveling at speeds over 1300 km/hour as well as rockets flying at speeds of more than 3000 km/hour. These were purely solutions todifferential equations which were allocated to various institutions for solving.[2]
A minor planet discovered on 15 February 1941 byKarl Wilhelm Reinmuth in Heidelberg was named "1561 Fricke" in his honour.[4] In 1942 he was appointed the assistant astronomer at theHamburg Observatory atBergedorf, but could only take the position up in 1946 due to conscription.[1]
In 1943 Fricke married Marianne Fricke (née Traute). They had a daughter, Maxi-Marianne Fricke. His wife Marianne died in 1987.
In 1951, he received hishabilitation fromUniversity of Hamburg. In 1953, after receiving afellowship from theGerman Science Foundation, he went to theUnited States for a year, working at theYerkes,Mount Wilson,Palomar andPrinceton University Observatories.[1] After returning, he became atenured member (Wissenschaftlicher Rat) of the Hamburg Observatory. In December 1954, Dr Fricke was made the provisional director of theAstronomical Calculation Institute in Heidelberg. Heidelberg University appointed him an honorary professor in 1955 and a personal full professor in 1958. In 1961 he became a regular full professor of theoretical astronomy at Heidelberg.[1]
Fricke served as president of theInternational Astronomical Union Commissions 4 (1958–1964) and 8 (1970–1973), and as vice president of the IAU from 1964 to 1967.[5]
On 1 April 1983 he retired as professor emeritus.Dr. Dr.h.c. mult.[1] Fricke stayed on as Director of the Institute until 30 September 1985, and continued his scientific work until he was hospitalized with cancer in 1987.[1]
Fricke had a wide interest in astronomy. His first publications dealt with problems intheoretical andobservational astronomy. Then for the next two decades, from the time of his thesis onwards, his interests focused onstellar dynamics, working from the observatory inBergedorf. His favourite subject was the photographic surfacephotometry survey of theAndromeda Nebula.[1]
In addition, in 1951 he published withOtto Heckmann andPascual Jordan an important work for the extension ofEinstein's theory of gravity.[6]
After being appointed to the Astronomical Calculation Institute, Fricke concentrated on fundamentalastrometry. He worked specifically to improve the fundamental reference system, a series of measurements of the position and motions of a series of fundamental stars that is important for study of kinematics and dynamics of objects within the Galactic system.[1] The production of this kind of fundamental catalogue, which provided the astronomical representation of an inertial system, was part of the institute's important work. His finest contribution to astronomy was the derivation, together with his colleagues and his predecessorAugust Kopff, of theFourth Fundamental Catalogue (FK4), published in 1963.[1] The FK5 catalogue was strongly associated with his name, but he was unable to view it when it was published; it used a new constant of precession which he derived himself[7] and adopted by the IAU in 1976.[1]
Fricke made significant contributions toward the establishment of theEuropean Southern Observatory in 1962 and theMax Planck Institute for Astronomy (Max-Planck-Institut für Astronomie) in Heidelberg, withits observatory inCalar Alto, Spain.[1]
While in the military, Fricke studied German cipher methods and devised new ones.[2]
Fricke's initial task was working on the solving of the double stop system, NS 42, code named theDouble Playfair (Doppelkastenschlüssel).[2] TheArmy,Air Force andPolice used the Double Playfair system as a medium-grade hand cipher in World War II. ThePlayfair TS 42 single stop system had already been broken at that point if there were more than 3000 letters of traffic a day. After a year's work, they solved the problem by using verticalbigram frequencies. As the text was written in double lines of 17 or 21 and the substitutions taken vertically, plain text bigram frequencies could not be used. Combined frequencies of pairs of single letters showed a sharp drop after the top three values, EE, EN and NE (the last two had the same frequency). Of a text length of 10000, they could place the three values only initially.Hollerith counts (frequency analysis) were undertaken against messages from thePolish War, but as these were of a stereotypical nature, words could only be guessed after high-frequency digraphs (i.e. pairs of letters) had been created. Using this method led to the recovery of more pairs, and the guessing of words. However, the solution was never used, as even though they believed 3000 letters would be enough to break a message, the Army never informed them what the actual volume of traffic was, so the system continued in use.[2]
Around the same time, he worked on the FrenchC36 cipher machine with fixed lugs, designed byBoris Hagelin, which was solved bycribs. He later heard from others that cribs were no longer needed.[2]
The head of his section at OKH/Chi (Army Cipher Office) wasHans Pietsch, who managed eight mathematicians in the group. He remained there until 1 November 1944, when he was transferred to theOKW/Chi. At this timeInspektorate 7 was forbidden to create new systems, which was strictly restricted to OKW/Chi.[2] At OKW/Chi, Dr Fricke managed Section IIb of Chi II (Group 2), the main group managing OKW/Chi's interception services. Section IIb, which developed German code and cypher systems (camouflage, codes and cyphers, and telephone secrecy) and also advised on the production of keys and the supervision of production, had a staff of 14. OKW/Chi cipher bureau was a strictly military organization.
In 1942, he developed the codebook (Schlüsseltafel) for enciphering tables for 3 letter field codes. Before that were used withoutencipherment. Daily changingtrigraphic substitution tables were introduced, initially made by Hollerith machines. He stated in hisTICOM interview that there were two master decks of 500 cards each, with a trigraph on each card. Late in the war, the Hollerith machine section moved toWeimar, so Walter Fricke told the printer to make up a set of three-letter slugs of type corresponding to the code groups, which were calledLogotypen. The printer had the plain code values in alphabetical order in a form, with blank spaces for the encrypted values. He was told to draw two logos from the mixed batch and place the second one opposite that plain value which was the same as the first. This procedure was repeated until the reciprocal table was created. It also had the effect of enabled untrained workers to make fewer mistakes.[2]
He went on to design and develop theraster key hand cipher (Rasterschluessel 44), which was to replace thedouble playfair cipher. A study was made on the British cipherraster,Cysquare which was created byJohn Tiltman in 1941. The Cysquare cipher had been pinched from Britain, whenRommel'sAfrika Korps overran British units and captured the Cysquare[8] and pads with their instruction booklets. Fricke found it to be excellent, a very secure and practical hand cipher, but he didn't know if it had been broken, with the English using 40 letters and large number of abbreviations. He knew that if German forces used the cipher as it was, it soon would be broken because of longer messages.[2] In order to use longer messages, 26 rows were created, of which 24 were used at any one time. The requirement was to choose all rasters from a systematically constructed field, and to satisfy the following requirements simultaneously:
These conditions were difficult to achieve, since as soon as one requirement was achieved the others would go wrong. The purpose of making all from the same field was to avoid special cases. However, they were eventually required to be made from 20 to 40 master fields. As regards changing keys, the printer was given lead strips bearing the pattern of each of the 36 rows, of which 24 were chosen for each raster. The minimum message length was initially set to 60 characters but was lowered to 45 by the army after some use.[2] Fricke asked the TICOM interrogators
They reflected on the fact that the work on Russian systems showed that these systems were secure if properly used, but if the cryptographers inMoscow could only see how they were used they would be very unhappy.
Parts of this article have been sourced fromTICOM document:
