Security, also known as Alliance Security, was a branch of Alliance Intelligence's Counter-Intelligence department. Security was tasked with recruiting agents and deploying them within other sections of the Alliance. The number of operatives and their assignments assigned to Security was a closely guarded secret, with even Chief of State Mon Mothma unaware of their true strength. Two undercover Security operatives were assigned to Mon Mothma's staff disguised as aides. If a Security operative suspected an individual of being an Imperial Intelligence agent, Security would turn the case over to Retrieval for follow up and prosecution.
Following the Battle of Endor, Tycho Celchu was guarded by Alliance Security guards due to General Salm's suspicions of him being an Imperial spy. Alliance Security assisted Rogue Squadron prior to the Battle of Coruscant in freeing several known criminals from the prison world of Kessel. They were then brought to Coruscant to distract Imperial forces while the New Republic seized the capital.
- X-Wing: Rogue Squadron (First appearance)
- X-Wing: Wedge's Gamble
- X-Wing: The Bacta War (Mentioned only)
- Rebel Alliance Sourcebook
- Rebel Alliance Sourcebook, Second Edition
- Star Wars: Edge of the Empire Core Rulebook