What is "bullrun"

Bullrun is an American reality television series based on the trans-American Bullrun road rally of the same name. The televised version has 12 teams compete in a 4,000-mile (6,400 km) 18-day road rally to win the grand prize of US$200,000. Bullrun uses a modified 12-car rally format.

Bullrun (stylized BULLRUN) is a clandestine, highly classified decryption program run by the United States National Security Agency (NSA). The British Government Communications Headquarters (GCHQ) has a similar program codenamed Edgehill. According to the BULLRUN classification guide published by The Guardian, the program uses multiple sources 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. 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 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 regarding the program found in Snowden's documents were additionally censored by the press at the behest of US intelligence officials. Out of all the programs that have been leaked by Edward Snowden, the Bullrun Decryption Program is by far the most expensive. Snowden claims that since 2011, expenses devoted to Bullrun amount to $800 million. The leaked documents reveal that Bullrun seeks to "defeat the encryption used in specific network communication technologies."