Claude Shannon

It was Shannon, for example, who proved that the only provably secure cryptosystem is one in which the key is as long as the information to be transmitted. In other words, the One Time Pad.

Boolean Algebra, far from being an obscure field of mathematics, is absolutely essential to Computer Science. The circuits in the computer you are using right now (and in fact every digital computer in existence) are based on boolean algebra.

His Master's Thesis is widely recognized as one of the most influential technical theses of all time.

When asked why he pursued the topics he did he once remarked, "I just wondered how things were put together." Hopefully, now he knows. The entropy of the universe increases...

Claude Elwood Shannon was born in Gaylord, Michigan, on 30 April 1916. As a boy he worked on radios, building his own and mending other peoples'. He entered the University of Michigan in 1932, studying electrical engineering and mathematics, and MIT in 1936, where he worked with Vannevar Bush. He worked as an intern at Bell Labs in the summer of 1937; he joined them full-time in 1941.

He worked on anti-aircraft systems at Bell as well as cryptography, because the rapid calculation of position required the newly-emerging computer technology. He also met the mathematician Mary Elizabeth Moore there, whom he married in 1949. They had two sons and one daughter.

In 1958 he returned to MIT as Donnor Professor of Science, and retired in 1978. He received the National Medal of Science in 1966, and the Kyoto Prize in 1985. His retirement was spent at Mystic Lake, MA; in the end he succumbed to Alzheimer's disease, and died in a nursing home in Medford, MA.

He was the first to use "bit" for binary digit, a term he credited to John Tukey in the paper in which he introduced it.

Information extracted from his obituary in The Independent, 9 April 2001. (And I have to say it is shameful that they didn't have an obit already on file for him.)

Thanks to WaldemarExkul for mentioning that he credited Tukey.