Claude Shannon's cryptography research during World War II and the mathematical theory of communication

Dr. Claude E. Shannon, the eminent mathematician and electrical engineer at Bell Labs., worked on cryptographic research from 1940 to 1945. He proved mathematically that the SIGSALY coding system linking the U.S. President with Prime Minister Winston Churchill by radio-telephone could not be broken by the Germans. As part of the same activity at a theoretical level, Shannon developed the mathematical theory of communication, published in 1948, which was to become the root paradigm for the emerging field of communication study.<
>