The Communications Security Establishment, formerly called the Communications Security Establishment Canada (CSEC), is the Government of Canada's national cryptologic agency. It is responsible for foreign signals intelligence (SIGINT) and communications security (COMSEC), protecting federal government electronic information and communication networks, and is the technical authority for cyber security and information assurance.

The Department of National Defence is the department of the Government of Canada which supports the Canadian Armed Forces in its role of defending Canadian national interests domestically and internationally. The department is a civilian organization, part of the public service, and supports the armed forces; however, as a civilian organization is separate and not part of the military itself. National Defence is the largest department of the Government of Canada in terms of budget, and it is the department with the largest number of buildings.