The Australian Signals Directorate (ASD, formerly DSD) is an intelligence agency in the Australian Government Department of Defence.

ASDs role is to:◾collect and analyse foreign signals intelligence, known as Sigint◾provide advice and assistance on information and communications security, known as InfoSec.

ASD provides information security advice and services mainly to Australian federal and state government agencies. ASD also works closely with industry to develop and deploy secure cryptographic products.