National Security Agency

Overview

The National Security Agency is the United States' signals-intelligence and information-security agency. It collects, processes, and disseminates foreign signals intelligence; designs and accredits the cryptographic systems that protect US national-security information; and, since 2009, has been co-located with US Cyber Command, which the NSA Director also commands in a "dual-hat" arrangement.¹

The Agency is a Department of Defense component but reports through the Director of National Intelligence in its intelligence-collection role. It is the largest US intelligence agency by both budget and personnel — figures that remain partly classified — and is headquartered at Fort George G. Meade, Maryland, in a complex large enough to support its own internal road system, fire department, and police force.²

History & Origins

The NSA was established on 4 November 1952 by a classified seven-page memorandum from President Truman that authorised the consolidation of US signals intelligence under a single defence-department agency. Its existence was formally acknowledged only in 1957. The Agency's predecessors were the Armed Forces Security Agency (1949–1952), the wartime Signal Intelligence Service of the US Army, and, further back, the Cipher Bureau — known as the "Black Chamber" — operated jointly by the State and War Departments from 1919 until Secretary of State Henry Stimson closed it in 1929.³

For its first two decades the Agency operated under almost no congressional oversight. The first sustained public scrutiny came with the Church Committee investigations of 1975–76, which uncovered Project SHAMROCK and Project MINARET — programmes through which the Agency had, since the late 1940s, intercepted international cable traffic and maintained watch lists of US citizens including senators, athletes, and civil-rights figures. The Foreign Intelligence Surveillance Act of 1978 imposed the first statutory regime governing the Agency's collection of communications involving US persons.⁴

The post-September 2001 period saw a substantial expansion of NSA collection authorities and, in June 2013, the largest unauthorised disclosure in the Agency's history when former contractor Edward Snowden provided journalists with a body of internal documents detailing programmes including the bulk collection of US telephony metadata, downstream collection from US technology companies (PRISM), and broad-spectrum signals collection partnerships with Five Eyes services.⁵

Mandate & Jurisdiction

The Agency's authorities derive from National Security Council Intelligence Directives, the Foreign Intelligence Surveillance Act, Section 702 of the FISA Amendments Act of 2008, and Executive Order 12333. Its statutory functions are:

• foreign signals-intelligence collection, processing, and analysis;
• information-assurance and cryptographic-systems design and accreditation for national-security systems;
• protection of US government communications;
• support to military operations and combat support to the Department of Defense;
• since 2009, support to US Cyber Command's offensive and defensive cyber operations.¹

Domestic collection of US-person communications is permitted only under FISA-authorised processes. Bulk telephony-metadata collection under Section 215 of the PATRIOT Act, ruled in 2015 by the Second Circuit Court of Appeals to exceed statutory authority, was wound down by the USA FREEDOM Act of 2015.⁶

Notable Operations

Confirmed Project SHAMROCK (1945–1975). A signals-intelligence programme under which the Agency and its predecessors obtained, with the cooperation of RCA Global, ITT World Communications, and Western Union International, copies of essentially all international telegram traffic transiting the United States — an estimated 150,000 messages per month at its peak. The programme operated for thirty years without legislative authorisation and was disclosed by the Church Committee in 1975.⁷

Confirmed Project MINARET (1967–1973). A watch-list programme under which Agency analysts targeted communications of named US citizens — including senators Frank Church and Howard Baker, the boxer Muhammad Ali, and the journalist Tom Wicker — at the request of the FBI, CIA, and other agencies. The programme was determined by the Church Committee, and later by the NSA's own retrospective declassification in 2013, to have lacked any lawful authority.⁸

Alleged ECHELON. A signals-collection partnership among the Five Eyes services (NSA, GCHQ, CSE, ASD, GCSB) targeting global commercial-satellite communications. The European Parliament's 2001 report concluded that the system existed and was used for both intelligence and economic-intelligence purposes; participating governments have not formally confirmed its name or scope.⁹

Confirmed Operation OLYMPIC GAMES / Stuxnet (c. 2007–2010). A cyber-sabotage operation, jointly conducted with the Israeli signals service Unit 8200, that introduced a sophisticated worm into the Natanz uranium-enrichment facility in Iran and physically damaged centrifuges. US officials confirmed the operation in interviews with the New York Times' David Sanger, and elements were later detailed in court filings concerning leaks.¹⁰

Confirmed Bulk telephony-metadata collection under Section 215 (2006–2015). The Agency obtained, under repeated orders from the Foreign Intelligence Surveillance Court, comprehensive call-detail records from major US telecommunications carriers. The programme was disclosed by the Guardian in June 2013 from documents provided by Edward Snowden, ruled likely unlawful by the Privacy and Civil Liberties Oversight Board in 2014, and ended by Congress in the USA FREEDOM Act.¹¹

Confirmed PRISM (2007–present). Downstream collection of communications from major US technology providers under FISA Section 702. The programme was disclosed in June 2013 from Snowden documents and substantially confirmed by the Director of National Intelligence in subsequent statements. Section 702 has been reauthorised by Congress on multiple occasions, most recently in 2024.¹²

Confirmed Upstream and XKeyscore. "Upstream" collection at internet backbone points and the XKeyscore search system, both disclosed in 2013, were acknowledged in successive Privacy and Civil Liberties Oversight Board reports.¹³

Controversies & Abuses

Confirmed The Snowden disclosures. In May–June 2013 contractor Edward Snowden provided documents to journalists Glenn Greenwald, Laura Poitras, and Barton Gellman that detailed dozens of NSA programmes. The disclosures triggered the most sustained public debate over US surveillance authorities in three decades, the work of the President's Review Group on Intelligence and Communications Technologies, and, ultimately, the limited reforms of the USA FREEDOM Act.¹⁴

Confirmed BULLRUN and the deliberate weakening of cryptographic standards. Documents disclosed in 2013 described an NSA programme to undermine commercial cryptographic systems through a combination of covert influence on standards bodies, partnerships with vendors, and direct cryptanalytic attack. The most-cited case is the Dual_EC_DRBG random-number generator standardised by NIST, which was withdrawn in 2014 after evidence emerged that it contained a backdoor.¹⁵

Confirmed The Shadow Brokers leak (2016–2017). A still-unattributed group released a series of NSA cyber tools — including the Windows exploit EternalBlue — which were subsequently used by other actors in the WannaCry and NotPetya cyber-attacks of 2017.¹⁶

Notable Figures

• William F. Friedman — Pre-eminent American cryptanalyst; broke Japan's PURPLE cipher and shaped the institution that became NSA.
• Lieutenant General Michael V. Hayden — Director 1999–2005. Director during the introduction of the warrantless-wiretapping programmes that became public in 2005.
• General Keith Alexander — Director 2005–2014. Director during the Snowden disclosures.
• Admiral Michael S. Rogers — Director 2014–2018. Period of the Shadow Brokers leak.
• General Paul M. Nakasone — Director 2018–2024. Stewardship of the dual-hat with US Cyber Command and Section 702 reauthorisation.

Oversight & Accountability

The Agency is subject to oversight by the Senate Select Committee on Intelligence, the House Permanent Select Committee on Intelligence, the Senate and House Armed Services Committees, the Foreign Intelligence Surveillance Court, the Privacy and Civil Liberties Oversight Board, the Department of Defense and Intelligence Community Inspectors General, and — for FISA Section 702 — quarterly compliance reporting to Congress and the FISC.

The 2014 reports of the Privacy and Civil Liberties Oversight Board on Section 215 and Section 702 remain the most comprehensive public-record evaluations of NSA programmes by an independent statutory body.¹⁷

Sources & Further Reading

1. National Security Council Intelligence Directive No. 6, "Signals Intelligence" (revised, declassified excerpts); Executive Order 12333; Department of Defense, "Memorandum of Agreement Between the Department of Defense and the Director of National Intelligence Concerning the National Security Agency."
2. James Bamford, The Shadow Factory: The Ultra-Secret NSA from 9/11 to the Eavesdropping on America (Doubleday, 2008); Office of the Director of National Intelligence, annual Statistical Transparency Report.
3. Truman Memorandum, "Communications Intelligence Activities," 24 October 1952, declassified excerpts; David Kahn, The Codebreakers (Macmillan, 1967, rev. 1996).
4. United States Senate, Final Report of the Select Committee to Study Governmental Operations with Respect to Intelligence Activities ("Church Committee Reports"), Book III, 1976.
5. Glenn Greenwald, No Place to Hide: Edward Snowden, the NSA, and the U.S. Surveillance State (Metropolitan, 2014); Barton Gellman, Dark Mirror: Edward Snowden and the American Surveillance State (Penguin Press, 2020).
6. USA FREEDOM Act, Pub. L. 114-23, 2 June 2015; ACLU v. Clapper, 785 F.3d 787 (2d Cir. 2015).
7. Senate Select Committee on Intelligence, "Hearings on the National Security Agency and Fourth Amendment Rights," 29 October 1975 and 6 November 1975.
8. National Security Agency, "MINARET" history, declassified 25 September 2013, available at the National Security Archive, George Washington University.
9. European Parliament Temporary Committee on the ECHELON Interception System, "Final Report," 11 July 2001.
10. David E. Sanger, "Obama Order Sped Up Wave of Cyberattacks Against Iran," New York Times, 1 June 2012; Kim Zetter, Countdown to Zero Day (Crown, 2014).
11. Glenn Greenwald, "NSA collecting phone records of millions of Verizon customers daily," Guardian, 5 June 2013; Privacy and Civil Liberties Oversight Board, "Report on the Telephone Records Program Conducted Under Section 215 of the USA PATRIOT Act," 23 January 2014.
12. Privacy and Civil Liberties Oversight Board, "Report on the Surveillance Program Operated Pursuant to Section 702 of the Foreign Intelligence Surveillance Act," 2 July 2014; reauthorisations of FISA Section 702, 2017 and 2024.
13. Glenn Greenwald, "XKeyscore: NSA tool collects 'nearly everything a user does on the internet,'" Guardian, 31 July 2013.
14. President's Review Group on Intelligence and Communications Technologies, Liberty and Security in a Changing World, 12 December 2013.
15. Nicole Perlroth, Jeff Larson, and Scott Shane, "N.S.A. Able to Foil Basic Safeguards of Privacy on Web," New York Times, 5 September 2013; National Institute of Standards and Technology, withdrawal of SP 800-90A Rev. 1, 21 April 2014.
16. Scott Shane, Nicole Perlroth, and David E. Sanger, "Security Breach and Spilled Secrets Have Shaken the N.S.A. to Its Core," New York Times, 12 November 2017.
17. PCLOB Section 215 and Section 702 reports, 2014; subsequent PCLOB oversight letters and recommendations, 2018–2023.