The National Security Authority is an interdepartmental committee with membership from the Department of Foreign Affairs and Trade, the Department of Defence, the Department of Justice and Equality and the Department of Communications, Climate Action and Environment. An Garda Síochána and the Irish Defence Forces also participate and the Department of Business, Enterprise and Innovation and agencies and the Department of An Taoiseach participate periodically.
The NSA was established by Government Decision in 1998 to facilitate the exchange of classified information between the now defunct Western European Union and Ireland. The Government also decided, in 2001, to extend the responsibility of the NSA to the protection of classified information between the European Union and Ireland as set out in Decision 2001/264/EC, which was subsequently replaced by Decision 2011/292/EU and then by the currently applicable Decision 2013/488/EU.
These Decisions establish minimum rules for the protection of EU classified information.
Under the Decisions, each Member State designates an NSA to be the body responsible for the protection of EU classified information in that State.
The Department of Foreign Affairs and Trade chairs the NSA and in doing so coordinates the responsibilities of Departments with respect to the Decision.