Bullrun (stylized BULLRUN) is a
clandestine, highly classified program to crack encryption of online communications and data, which is run by the United States
National Security Agency
The National Security Agency (NSA) is a national-level intelligence agency of the United States Department of Defense, under the authority of the Director of National Intelligence (DNI). The NSA is responsible for global monitoring, collectio ...
(NSA).
The British
Government Communications Headquarters
Government Communications Headquarters, commonly known as GCHQ, is an intelligence and security organisation responsible for providing signals intelligence (SIGINT) and information assurance (IA) to the government and armed forces of the ...
(GCHQ) has a similar program codenamed Edgehill. According to the Bullrun classification guide published by ''
The Guardian
''The Guardian'' is a British daily newspaper
A newspaper is a periodical publication containing written information about current events and is often typed in black ink with a white or gray background.
Newspapers can cover a wide ...
'', the program uses multiple methods including computer network exploitation,
interdiction, industry relationships, collaboration with other
intelligence community entities, and advanced mathematical techniques.
Information about the program's existence was leaked in 2013 by
Edward Snowden
Edward Joseph Snowden (born June 21, 1983) is an American and naturalized Russian former computer intelligence consultant who leaked highly classified information from the National Security Agency (NSA) in 2013, when he was an employee and s ...
. Although Snowden's documents do not contain technical information on exact cryptanalytic capabilities because Snowden did not have clearance access to such information, they do contain a 2010
GCHQ
Government Communications Headquarters, commonly known as GCHQ, is an intelligence and security organisation responsible for providing signals intelligence (SIGINT) and information assurance (IA) to the government and armed forces of the Uni ...
presentation which claims that "vast amounts of encrypted Internet data which have up till now been discarded are now exploitable".
A number of technical details regardi