A satellite network will beam quantum-encrypted keys across the globe at a billion pulses per second, fast enough to secure real-time data traffic between continents. Today’s fibre-optic quantum links die out after about 175 kilometres, and existing satellite quantum key distribution (QKD) systems are too slow and require bulky telescopes to generate enough encryption material for even a single ground station. This leaves long-distance data—financial transactions, health records, government communications—vulnerable to future quantum computers that could crack classical encryption like RSA and AES. The project tackles both bottlenecks: it will build hardware and software for satellite-to-ground QKD that operates at gigahertz clock rates, and integrate those keys into terrestrial fibre networks to create a seamless global system. If successful, the technology could make intercontinental data transfer resistant to quantum attacks without requiring new ground infrastructure. The impact would be felt in the quiet backbone of the digital economy—the undersea cables, data centres, and routing hubs that handle trillions of dollars in transactions daily. For the first time, a city in London could exchange a secure quantum key with a counterpart in Sydney in real time, not just over a single fibre span.
View original technical description
Data is fast becoming the underlying driver of the global economy. Securing the transmission of data as it is routed around the world is therefore of utmost importance. Today we use classical cryptography protocols, such as RSA and AES, to secure a wide range of sensitive data including financial data, health records, commercial secrets, and sensitive governmental and defence information. However, this data is at threat from attacks by quantum computers. As the resource of quantum computers grows, their ability to break traditional cryptographic protocols becomes ever more likely. Quantum cryptographic methods such as quantum key distribution (QKD) are, by nature, resistant to these attacks and they can secure our data now and into the future. A typical link between two users that is secured by QKD is serviced by fibre-optics and is limited in distance to approximately 175 km. This is because the inherent losses of fibre-optic cables means that above these distances there is too little signal to perform the QKD protocol. To overcome this limit, we can use free-space links, which can have much lower losses per unit distance. Recently, there has been a push toward performing QKD that is intermediated by satellites in low-Earth orbit. This type of satellite-to-ground QKD can break the distance limit and allow for secure communication between users separated by intercontinental distances. Current implementations of satellite QKD (SQKD) suffer from impracticalities arising from slow clock rates and the requirement of large telescopes to provide enough encryption material to service even a single ground node. In this project we will develop technology for high-rate SQKD and integrate this technology to ground networks enabling secure communication across the globe. The hardware and software developed will overcome current limitations by operating in real-time and at gigahertz (1 billion Hz) clock rates. Furthermore, software to share quantum keys between ground nodes serviced by SQKD will be developed to seamlessly secure data transfer around the world.
Plain English summaries and category classifications on this site are generated by AI and may not perfectly reflect the original research.
Is something wrong? Let us know