Quantum communications

Long-distance quantum communication depends on scalable hardware systems that can generate, manipulate, store and amplify fragile quantum signals. The HTSN Challenge program supports NRC collaborations with academic partners across Canada to advance core components. For example, under the program, the NRC is partnering with the University of Calgary to design quantum memories and quantum repeaters—key enablers of scalable quantum networks. Complementing this work, HTSN Challenge program collaborations are advancing fabrication platforms for next-generation quantum devices. This includes 2D material processing, with the University of Ottawa, and an ultra-low-loss silicon nitride material platform, developed with Carleton University—2 platforms that are critical for scalable, high-throughput quantum photonic circuits. The NRC also worked with McMaster University and the University of Waterloo in research to develop a chip-based entangled photon source designed for satellite links that could deliver high signal rates, achieve greater energy efficiency and demonstrate compatibility with fibre networks.

To build a global quantum communications network, different forms of technology must be connected together. The HTSN Challenge program is helping drive the development of robust, high-fidelity quantum links that allow fibre networks, terrestrial free-space links and satellite links to work together to form larger quantum networks. In collaboration with the University of Ottawa, the HTSN Challenge program made a major infrastructure investment that helped establish a dedicated lab and experimental platform to explore high-dimensional quantum communication over free-space links. The platform made it possible to develop advanced temporal and spatial encoding techniques for next-generation quantum key distribution (QKD) protocols with enhanced security. Building on these advances, researchers have developed a QKD system that uses structured photons and adaptive optics to mitigate the effects of atmospheric turbulence while also maintaining the integrity of the quantum signal. This technology has been successfully demonstrated on a secure 5.4-km free-space link between the NRC and the University of Ottawa. To extend the reach of quantum networks beyond the limits of fibre infrastructure, the HTSN Challenge program partnered with the CSA on the development of an optical quantum ground station as part of Canada's QEYSSat mission, to support the goal of enabling secure quantum key distribution between earth and space. At the same time, the NRC, the CSA, the University of Waterloo and the German Aerospace Center are also working together to define technical interfaces and characterize atmospheric conditions at multiple satellite–ground stations.

Securing sensitive information in the quantum era requires cryptographic systems that will remain safe even in the presence of the powerful quantum computers of the future. The NRC is helping drive quantum-safe communication by developing key distribution networks and scalable protocols that provide strong, future-proof security guarantees. Central to this effort is quantum key distribution (QKD), which uses the principles of quantum mechanics to detect in real time any interception of encryption keys.

In collaboration with evolutionQ, a technology company that specializes in the field of quantum-safe cryptography, the HTSN Challenge program supported the company's work investigating QKD in secure network environments. This work not only led to a commercial software product and helped set international best practices, but also helped support the Government of Canada in preparing for quantum-secure technologies. In a final HTSN Challenge program project, the NRC is collaborating with Quantum Bridge Technologies and the University of Toronto to demonstrate a distributed key exchange system designed for long-range deployment. Together, these technologies advance secure quantum communication between urban centres and remote regions, strengthening Canada's digital infrastructure against emerging quantum threats.