Space-to-Ground Integrated Quantum Networks (SIQN)

数据正迅速成为全球经济的根本驱动力。因此，确保数据在世界各地传输时的安全至关重要。如今，我们使用经典加密协议(如RSA和AES)来保护范围广泛的敏感数据，包括金融数据、健康记录、商业机密以及敏感的政府和国防信息。然而，这些数据正受到量子计算机攻击的威胁。随着量子计算机资源的增长，它们打破传统密码协议的能力变得越来越有可能。量子密钥分发(QKD)等量子加密方法本质上是抵抗这些攻击的，它们可以保护我们现在和未来的数据。由QKD保护的两个用户之间的典型链路由光纤提供服务，距离限制在大约175公里。这是因为光纤电缆的固有损耗意味着超过这些距离的信号太少，无法执行QKD协议。为了克服这一限制，我们可以使用自由空间链路，这种链路的单位距离损耗要低得多。最近，有一种由近地轨道上的卫星中介的量子密钥分配得到了推动。这种类型的星对地量子密钥分配可以打破距离限制，并允许相隔洲际距离的用户之间的安全通信。目前卫星量子密钥分配(SQKD)的实现受到时钟速率缓慢和要求大型望远镜提供足够的加密材料以服务于甚至单个地面节点的不切实际的影响。在这个项目中，我们将开发用于高速率SQKD的技术，并将该技术集成到地面网络中，从而实现全球范围内的安全通信。开发的硬件和软件将通过以千兆赫兹(10亿赫兹)时钟速率实时运行来克服当前的限制。此外，将开发在由SQKD服务的地面节点之间共享量子密钥的软件，以无缝地保护数据在世界各地的传输。

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.