Solomon Kullback

Solomon Kullback ( born April 4, 1907 in Brooklyn, New York; † August 5, 1994 in Boynton Beach, Florida ) was an American mathematician ( statistics) and cryptologist.

Kullback attended Boys High School in Brooklyn and studied at the City College of New York. He then taught mathematics in New York, but was like his school friend Abraham Sinkov dissatisfied and applied as a mathematician for the Civil Service. They were accepted by William Friedman in 1930 for the Signals Intelligence Service ( SIS) and in Washington, DC designed for cryptographers. In addition, Kullback 1934 doctorate at Frank M. Weida at George Washington University (An Application of Characteristic Functions to the distribution problem of Statistics ), where he was also from 1939 evening courses in mathematics.

In the 1930s, the SIS usually worked only on their own communications security ( COMSEC ). How Sinkov he also was involved in the production of code books for the U.S. Army, where she as a random element of the throw in the air card games used. In addition, they tested commercial offers of cipher machines, but they usually "crack" could. Kullback and Frank Rowlett ( who had also been recruited in 1930 ) but also started from 1936 in the Japanese diplomatic traffic break, which was encrypted with machine (codenamed Red ). From the deciphered messages, the U.S. got evidence of war preparations of the Axis powers. The financing of the SIS was then amplified.

In May 1942, Kullback worked as a Major in the United Kingdom, where he exchanged with the British and successfully worked on deciphering German codes. After his return he headed the Japan Department.

After the war he was in the 1952 founded NSA Head of Research and Development and directed especially the use of computers for their own new cipher. The other 1930 set by Friedman cryptographers had leadership positions: Sinkov for message security ( COMSEC ) and Rowlett for cryptanalysis.

1962 Kullback went at NSA in retirement and became a professor at the George Washington University with a focus on statistics. According to him and Richard Leibler the Kullback -Leibler divergence is named.