This unofficial account of Australian Signals intelligence reveals the organisation's efforts to reveal the secrets of others.

What is Australian signals intelligence? Why do we have a national signals intelligence agency and why are our three armed services involved? What do they all do and why is it controversial? And how significant are our ties with the United States, the United Kingdom, Canada and New Zealand, the formidable Five Eyes partnership?

For a long time, much of the Australian Signals intelligence (or Sigint) story has been kept secret. Revealing Secrets unearths the fascinating story of the organisation that collects intelligence about foreign adversaries, and keeps our own national secrets safe, not forgetting the vital signals intelligence contribution of our three armed services. This book provides historical context, including how techniques used today for breaking codes draw on methods devised centuries earlier. It explains clearly what Sigint is, how it works and its connection with cyber. Security experts John Blaxland and Clare Birgin shine a light on the Australians whose efforts were for so long unknown and why they were so important to the country. They discuss the essential, and largely unheralded, contribution of women from before the Second World War to today. By lifting the veil on this hidden, frequently misunderstood, but absolutely integral part of Australian statecraft, Revealing Secrets deepens our understanding of the past, the present and what may lie ahead.

'Revealing Secrets tell the remarkable but little-known story of how a small, back-room military office grew into a major Australian government agency. Deeply researched, authoritative and accessible, it is a valuable and timely contribution to understanding issues that have never been more important to national security.' - Emeritus Professor David Horner, author of The Spy Catchers

'A meticulous compilation of the largely unsung past achievements of our most consistently productive intelligence source. And a thoughtful analysis of how to approach the extraordinary challenges posed by the new cyber universe. Blaxland and Birgin make an important contribution to our understanding of issues needing much more open debate than our own and allied governments have traditionally allowed or encouraged.' - Gareth Evans, Former Australian Foreign Minister