United States Naval Computing Machine Laboratory

The United States Naval Computing Machine Laboratory was a highly secret design and manufacturing site for code-breaking machinery located in Building 26 of the National Cash Register (NCR) company in Dayton, Ohio

Dayton, Ohio

Dayton is the 6th largest city in the U.S. state of Ohio and the county seat of Montgomery County, the fifth most populous county in the state. The population was 141,527 at the 2010 census. The Dayton Metropolitan Statistical Area had a population of 841,502 in the 2010 census...

and operated by the United States Navy

United States Navy

The United States Navy is the naval warfare service branch of the United States Armed Forces and one of the seven uniformed services of the United States. The U.S. Navy is the largest in the world; its battle fleet tonnage is greater than that of the next 13 largest navies combined. The U.S...

during World War II

World War II

World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...

. It is now on the List of IEEE Milestones, and one of its machines is on display at the National Cryptologic Museum

National Cryptologic Museum

The National Cryptologic Museum is an American museum of cryptologic history that is affiliated with the National Security Agency . The first public museum in the U.S. Intelligence Community, NCM is located in the former Colony Seven Motel, just two blocks from the NSA headquarters at Fort...

.

The laboratory was established in 1942 by the Navy and National Cash Register Company to design and manufacture a series of code-breaking machines ("bombe

Bombe

The bombe was an electromechanical device used by British cryptologists to help decipher German Enigma-machine-encrypted signals during World War II...

s") targeting German Enigma machine

Enigma machine

An Enigma machine is any of a family of related electro-mechanical rotor cipher machines used for the encryption and decryption of secret messages. Enigma was invented by German engineer Arthur Scherbius at the end of World War I...

s, based on earlier work by the British at Bletchley Park

Bletchley Park

Bletchley Park is an estate located in the town of Bletchley, in Buckinghamshire, England, which currently houses the National Museum of Computing...

(which in turn owed something to pre-war Polish cryptanalytical work). Joseph Desch

Joseph Desch

Joseph Raymond Desch was an American electrical engineer and inventor. During World War II, he was Research Director of the project to design and manufacture the US Navy version of the bombe, a cryptanalytic machine designed to read communications enciphered by the German Enigma.-Early life:Desch...

led the effort. Preliminary designs, approved in September 1942, called for a fully electronic machine to be delivered by year's end. However, these plans were soon judged infeasible, and revised plans were approved in January 1943 for an electromechanical machine, which became the US Navy bombe.

These designs were proceeding in parallel with, and influenced by, British attempts to build a high-speed bombe for the German 4-rotor Enigma. Indeed, Alan Turing

Alan Turing

Alan Mathison Turing, OBE, FRS , was an English mathematician, logician, cryptanalyst, and computer scientist. He was highly influential in the development of computer science, providing a formalisation of the concepts of "algorithm" and "computation" with the Turing machine, which played a...

visited Dayton in December 1942. His reaction was far from enthusiastic:

It seems a pity for them to go out of their way to build a machine to do all this stopping if it is not necessary. I am now converted to the extent of thinking that starting from scratch on the design of a Bombe, this method is about as good as our own. The American Bombe program was to produce 336 Bombes, one for each wheel order. I used to smile inwardly at the conception of Bombe hut routine implied by this program. Their test (of commutators) can hardly be considered conclusive as they were not testing for the bounce with electronic stop finding devices. Nobody seems to be told about rods or offiziers or banburismus

Banburismus

Banburismus was a cryptanalytic process developed by Alan Turing at Bletchley Park in England during the Second World War. It was used by Bletchley Park's Hut 8 to help break German Kriegsmarine messages enciphered on Enigma machines. The process used sequential conditional probability to infer...

unless they are really going to do something about it.

The American approach was, however, successful. The first two experimental bombes went into operation in May 1943, running in Dayton so they could be observed by their engineers. Designs for production models were completed in April, 1943, with initial operation starting in early June.

All told, the laboratory constructed 121 bombes which were then employed for code-breaking in the US Navy's signals intelligence and cryptanalysis group OP-20-G

OP-20-G

OP-20-G or "Office of Chief Of Naval Operations , 20th Division of the Office of Naval Communications, G Section / Communications Security", was the US Navy's signals intelligence and cryptanalysis group during World War II. Its mission was to intercept, decrypt, and analyze naval communications...

in Washington, D.C.

Washington, D.C.

Washington, D.C., formally the District of Columbia and commonly referred to as Washington, "the District", or simply D.C., is the capital of the United States. On July 16, 1790, the United States Congress approved the creation of a permanent national capital as permitted by the U.S. Constitution....

. Construction was accomplished in three shifts per day by some 600 WAVES

WAVES

The WAVES were a World War II-era division of the U.S. Navy that consisted entirely of women. The name of this group is an acronym for "Women Accepted for Volunteer Emergency Service" ; the word "emergency" implied that the acceptance of women was due to the unusual circumstances of the war and...

(Women Accepted for Volunteer Emergency Service), 100 Navy officers and enlisted men, and a large civilian workforce. Approximately 3,000 workers operated the bombes to produce "Ultra

Ultra

Ultra was the designation adopted by British military intelligence in June 1941 for wartime signals intelligence obtained by "breaking" high-level encrypted enemy radio and teleprinter communications at the Government Code and Cypher School at Bletchley Park. "Ultra" eventually became the standard...

" decryptions of German Enigma traffic.

According to a contemporary US Navy report (dated April 1944), the bombes were used on naval jobs until all daily keys had been run; then the machines were used for non-naval tasks. During the previous six months, about 45% of the bombe time had been devoted to non-naval problems carried out at the request of the British. British production and reliability problems with their own high-speed bombes had then recently led to construction of 50 additional Navy units for Army and Air Force keys.

Building

The building in Dayton, called Building 26 (Dayton) was an Art Deco design of Dayton firm Schenck & Williams

Schenck & Williams

Schenck and Williams was an architectural firm in Dayton, Ohio. The firm's projects included the Hawthorn Hill home for Orville Wright and his sister and father, the Dayton Young Men's Christian Association Building, and the Engineers Club of Dayton building. The firm's partners were Harry J...

. It was owned by the University of Dayton in 2007, and they wanted to tear it down for a development. Residents protested.

Building

See also