The history of ASD begins in the Second World War, when Australian Navy, Army and Air Force personnel were brought together to support General MacArthur’s South-West Pacific campaign by intercepting and decoding Japanese radio signals.
Before that, Navy, Army and Air Force ‘wireless’ units and intercept stations operated independently, conducting mainly radio intercept and direction-finding activities. While they achieved many successes, there was no central coordination.
From early 1942, Australian, American and British personnel worked together in Central Bureau, Melbourne, attached to General MacArthur’s headquarters, while the joint Australian-American Fleet Radio Unit Melbourne (FRUMEL) supported the US Navy’s 7th Fleet. Late in 1942, Central Bureau moved to Brisbane, following MacArthur’s headquarters, and elements of the bureau deployed with him to the Philippines later in the war.
After the war, as the wartime signals intelligence units were wound down, government approval for a new peacetime signals intelligence organisation was given on 23 July 1946. The new Defence Signals Bureau opened at Albert Park Barracks, Melbourne, on 12 November 1947. Its role was to exploit foreign communications and be responsible for communications security in the armed services and government departments.
The bureau was renamed Defence Signals Branch in October 1949, a title it retained until January 1964, when it became the Defence Signals Division.
DSD’s intelligence role was formally acknowledged in 1977 in the Prime Minister's statement to the House of Representatives about the Hope Royal Commission into Intelligence and Security. As a result of the inquiry, DSD was renamed the Defence Signals Directorate and made directly responsible to the Secretary of the Department of Defence.
In 1979, DSD finally relocated from its ‘temporary’ accommodation in Albert Park to a new purpose-built facility in Melbourne’s historic Victoria Barracks. In 1986, DSD acquired Australia’s first supercomputer, a Cray Research system. A later Cray supercomputer was donated to the Powerhouse Museum in Sydney when it was decommissioned in 1994.
In June 1988, the government decided that DSD should move to Defence headquarters at Russell Offices, Canberra, to facilitate a closer relationship with Defence, other intelligence agencies and key government departments. The move was completed in two phases over Christmas 1991 and Christmas 1992, with the Minister for Defence officially opening the new office on 4 May 1992.
Recent years have seen a dramatic expansion of the information security role as a result of the explosive growth of the internet and moves to online service delivery by Australian governments. In January 2010 DSD established the Cyber Security Operations Centre to develop a comprehensive understanding of ICT security threats to critical Australian systems, and coordinate a response to those threats across government and industry.
In May 2013 DSD was renamed the Australian Signals Directorate (ASD) to reflect its whole-of-government role in support of Australia’s national security.
In November 2014, the Cyber Security Operations Centre evolved into the Australian Cyber Security Centre (ACSC), which is the next evolution of Australia's cyber security capability. CSOC was a Defence-based capability that hosted liaison staff from other government agencies. ACSC sees the co-location of all contributing agencies' cyber security capabilities.