Version 1 is famous for having founded Information Theory with one landmark paper that he published in 1948. However, he is also credited with founding both digital computer and digital circuit design theory in 1937, when, as a 21-year-old master's degree student at the Massachusetts Institute of Technology (MIT), he wrote his thesis demonstrating that electrical applications of boolean algebra could construct and resolve any logical, numerical relationship. It has been claimed that this was the most important master's thesis of all time.


    Shannon contributed to the field of cryptanalysis for national defence during World War II, including his basic work on codebreaking and secure telecommunications.

    Shannon was born in Petoskey, Michigan. His father, Claude, Sr. (1862 – 1934), a descendant of early settlers of New Jersey, was a self-made businessman, and for a while, a Judge of Probate. Shannon's mother, Mabel Wolf Shannon (1890 – 1945), the daughter of German immigrants, was a language teacher, and for a number of years she was the principal of Gaylord High School. Most of the first 16 years of Shannon's life were spent in Gaylord, Michigan, where he attended public school, graduating from Gaylord High School in 1932. Shannon showed an inclination towards mechanical and electrical things. His best subjects were science and mathematics, and at home he constructed such devices as models of planes, a radio-controlled model boat and a wireless telegraph system to a friend's house a half-mile away. While growing up, he also worked as a messenger for the Western Union company.


    His childhood hero was Thomas Edison, whom he later learned was a distant cousin. Both were descendants of John Ogden, a colonial leader and an ancestor of many distinguished people.


    In 1932, Shannon entered the University of Michigan, where he took a course that introduced him to the work of George Boole. He graduated in 1936 with two bachelor's degrees, one in electrical engineering and one in mathematics. He soon began his graduate studies in electrical engineering at the Massachusetts Institute of Technology (MIT), where he worked on Vannevar Bush's differential analyzer, an early analog computer.


    While studying the complicated ad hoc circuits of the differential analyzer, Shannon saw that Boole's concepts could be used to great utility. A paper drawn from his 1937 master's degree thesis, A Symbolic Analysis of Relay and Switching Circuits, was published in the 1938 issue of the Transactions of the American Institute of Electrical Engineers. It also earned Shannon the Alfred Noble American Institute of American Engineers Award in 1940. Howard Gardner of Harvard University, called Shannon's thesis "possibly the most important, and also the most famous, master's thesis of the century."


    In this work, Shannon proved that boolean algebra and binary arithmetic could be used to simplify the arrangement of the electromechanical relays that were used then in telephone call routing switches. He next expanded this concept, and he also proved that it would be possible to use arrangements of relays to solve problems in Boolean algebra.

    Using this property of electrical switches to do logic is the basic concept that underlies all electronic digital computers. Shannon's work became the foundation of practical digital circuit design when it became widely known in the electrical engineering community during and after World War II. The theoretical rigor of Shannon's work completely replaced the ad hoc methods that had previously prevailed.


    Vannevar Bush suggested that Shannon, flush with this success, work on his dissertation at the Cold Spring Harbor Laboratory, funded by the Carnegie Institution, headed by Bush, to develop similar mathematical relationships for Mendelian genetics. This research resulted in Shannon's doctor of philosophy (Ph.D.) thesis at MIT in 1940, called An Algebra for Theoretical Genetics.


    In 1940, Shannon became a National Research Fellow at the Institute for Advanced Study in Princeton, New Jersey. In Princeton, Shannon had the opportunity to discuss his ideas with influential scientists and mathematicians such as Hermann Weyl and John von Neumann, and he even had an occasional encounter with Albert Einstein or Kurt Goedel. Shannon worked freely across disciplines, and began to shape the ideas that would become Information Theory.