Secure communications are crucial to a society whose economy, critical infrastructure and defense systems depend heavily on ICT. Current encryption methods are becoming increasingly insecure against (quantum) threats. A concurrent cyber security risk stems from the critical dependence of ICT infrastructure on timing signals from space-based GNSS systems. Quantum-secured communication promises a solution, but is currently limited in distance and timing functionality needs to be integrated.

Towards Long range quantum networks

The QUSTICS project goal is to research and develop a long-range quantum network that: 1) achieves coherent quantum links over 500+ km, where the frequency lock between two remote devices is sufficient to transmit qubit information, and this information can be reliably recovered at a receiver side 2) performs quantum key distribution over that link and distills raw detection data into useable, provably secure secret key material. 3) integrates with secure commercial timing solutions. Successful integration will allow for automatic secure key extraction to a White Rabbit device from a Q*Bird device.

Challenge for long range quantum networks

The main limiting factor for the distance is the nature of the quantum information, which is encoded into single photons. After long distances (>100km) there is a significant probability that the photon gets absorbed by the fiber, and therefore never arrives at the receiver side. To overcome this challenge, the partners explore an industrial implementation of a new QKD protocol using a different encoding scheme for the quantum information. Such new encoding schemes require innovative frequency locks between remote devices, which will be integrated into Q*Bird devices to provide secure key generation based on the established link, marking the second innovative solution, and a critical step for long range quantum network infrastructure.

Integrating quantum and timing protocols for secure timing and positioning

Finally, to demonstrate an industrial, full stack application of the solution, we will integrate the adapted Q*Bird devices with a White Rabbit device to use the generated key to secure timing data transmission. This will not only significantly advance the Dutch leadership in quantum network technology, but will benefit the wider telecom and GNSS network industry by delivering a ready-to-implement ultra-secure cryptography solution that will provide unparalleled secure timing and positioning solutions.