Ready for launch! Space-Qualified, entanglement-based QKD system to enable trusted-node satellite missions

Oct 16 2024, Singapore – SpeQtral has delivered the first of our space-qualified Entanglement-based QKD systems to RAL Space UK for integration into a joint Singapore-UK Satellite Quantum Key Distribution (QKD) mission, SpeQtre. The QKD system features an Entangled Photon Pair Source (EPPS) which functions as the core subsystem of the mission and is responsible for generating pairs of entangled photons that are used to establish quantum-secure encryption keys. It also includes SpeQtral’s four-state ‘Alice’ receiver module to analyse the polarisation states of photons on board the spacecraft.

This latest quantum optics system is an upgraded version of the world’s first space-qualified, miniaturised, entangled, photon pair source that was launched on SpooQy-1 3U CubeSat in 2019. Building on over a decade of knowhow and expertise inherited from the Centre for Quantum Technologies, the performance compared to SpooQy-1 has been significantly enhanced and it has successfully demonstrated the generation of quantum keys at mission realistic losses in terrestrial tests. A compact and set of Cubesat form factor modules (totalling 2U), SpeQtral’s space-qualified QKD system is a low SWAP payload which can be made compatible with satellite missions of any size and orbit.

The QKD system, which has been delivered to the UK for integration into the SpeQtre mission, is expected to fly on SpaceX’s transporter-14 mission next year. SpeQtre is a 12U QKD technology demonstrator satellite built by SpeQtral and RAL Space UK and will likely be the first entanglement-based QKD missions launched outside of China. It aims to demonstrate intercontinental, trusted node QKD by downlinking quantum keys to compatible Quantum-Optical Ground Stations (Q-OGS) across the world, including in Chilbolton, UK and Singapore.

The mission objective is to successfully demonstrate a form of entanglement-based QKD known as the BBM92 protocol. This is achieved by using the EPPS to generate pairs of photons entangled in polarisation. One of each of the photons in each pair is routed to an optical terminal, developed by RAL Space UK, to be downlinked to the Q-OGS, while another is routed internally to the ‘Alice’ quantum receiver on board the satellite. During a satellite ground station pass the polarisation of the photons is measured both on board the satellite as well as at the ground stations . A series of post-processing steps as per the BBM92 protocol are performed on the measured data to result in a shared, unique bit-string which can be used as a key to encrypt data communications.

SpeQtral is looking forward to embarking on new collaborations to enable future satellite QKD missions with the release of this space-qualified BBM92 system, and to use this same technology to enable double-downlink QKD missions to enable the highest levels of security in long range key distribution.

If you’re attending the International Astronautical Congress (IAC) from 14–17 October 2024, connect with SpeQtral Co-Founder and CEO, Chune Yang, and Director of Strategic Development, Joanne Liao, to learn more about our cutting-edge QKD solutions. Don’t miss the chance to meet our Co-Founder and CTO, Dr. Robert Bedington, and Head of Missions Engineering, Dr. Maximilian Boettcher, at the Space Tech Expo Europe in Germany this November. We’d love to discuss how our space-qualified, entanglement-based QKD systems can power your next mission. Reach out and let’s explore the future of secure satellite communications together!

For more information on SpeQtral’s products, check out https://speqtralquantum.com/ or reach out to us at info@speqtral.space.