This report examines the impact of quantum technologies on secure communications. It provides an overview of the key technologies and the status of the field in Australia and internationally (including escalating recent developments in both the US and China), and captures counterpart US, UK and Canadian reports and recommendations to those nations’ defence departments that have recently been released publicly.

The report is structured into six sections: an introduction that provides a stand-alone overview and sets out both the threat and the opportunity of quantum technologies for communications security, and more detailed sections that span quantum computing, quantum encryption, the quantum internet, and post-quantum cryptography. The last section of the report makes five substantive recommendations in the Australian context that are implementable and in the national interest.