The 1943 BRUSA Agreement was an agreement between the British

British Empire

The British Empire comprised the dominions, colonies, protectorates, mandates and other territories ruled or administered by the United Kingdom. It originated with the overseas colonies and trading posts established by England in the late 16th and early 17th centuries. At its height, it was the...

 and US

United States

The United States of America is a federal constitutional republic comprising fifty states and a federal district...

 governments to facilitate co-operation between the US War Department and the British Government Code and Cypher School (GCCS). It followed the Holden Agreement of October 1942.

Colonel Alfred McCormack of the Special Branch of Military Intelligence Service

Military Intelligence Service (United States)

The Military Intelligence Service was a World War II U.S. military unit consisting of two branches, the Japanese American Unit described here and the German-Austrian Unit based at Camp Ritchie, described partly in Ritchie Boys. The unit described here was primarily composed of Japanese-American...

, Colonel Telford Taylor

Telford Taylor

Telford Taylor was an American lawyer best known for his role in the Counsel for the Prosecution at the Nuremberg Trials after World War II, his opposition to Senator Joseph McCarthy in the 1950s, and his outspoken criticism of U.S...

 of Military Intelligence, and Lieutenant Colonel William Friedman came to 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...

, the Government Code and Cypher School Headquarters in England

England

England is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west; the Irish Sea is to the north west, the Celtic Sea to the south west, with the North Sea to the east and the English Channel to the south separating it from continental...

 in April 1943. The British decided to inform them of their successes with Ultra. The American trio worked with Commander Edward Travis

Edward Travis

Sir Edward Wilfred Harry Travis KCMG CBE was a British cryptographer and intelligence officer, becoming the operational head of Bletchley Park during World War II, and later the head of GCHQ.-Career:...

 (RN), the head of the British COMINT facility.

This led to the signing of the 1943 BRUSA Agreement on 17 May, which was a formal agreement to share intelligence information. It covered:

• the exchange of personnel
• joint regulations for the handling and distribution of the highly sensitive material

Even today the security regulations, procedures and protocols for co-operation form the basis for all SIGINT

SIGINT

Signals intelligence is intelligence-gathering by interception of signals, whether between people , whether involving electronic signals not directly used in communication , or combinations of the two...

 activities of both the US National Security Agency

National Security Agency

The National Security Agency/Central Security Service is a cryptologic intelligence agency of the United States Department of Defense responsible for the collection and analysis of foreign communications and foreign signals intelligence, as well as protecting U.S...

 and the British GCHQ, see UK-USA Security Agreement.