Establishment of a signals intelligence organisation post Second World War
On 23 July 1946, the Australian Government approved in principle the establishment of the Signals Intelligence Centre in Melbourne as part of the British Commonwealth Signals Intelligence Organisation.
In April 1947, the Defence Signals Bureau was established within the Department of Defence as part of a joint intelligence organisation encompassing both the Defence Signals Bureau and the Joint Intelligence Bureau. The Defence Signals Bureau was established to function as the Government’s cryptologic and communications security agency. Its role was to exploit foreign communications and be responsible for communications security in the armed forces and government departments.

The following are links to historical documents that tell the story of the Australian Signals Directorate’s beginnings.