ReFQ: Modular WCP Sources & RFI Protocols for Space-based QKD Demonstrations

量子密钥分发(QKD)有望成为未来安全通信基础设施的重要组成部分。密钥是一种非常有价值的加密工具，用于保护有价值的敏感数据。目前的主要方法保护交易，包括移动电话、公司知识产权、外交电报和金融交易。向网络内的全局通信节点分发密钥是通常使用计算困难的数学(例如计算大数的素因数)来解决的挑战。因此，这些密钥的安全性是基于这样的前提：相对于数据的价值，计算成本仍然高得离谱且昂贵。这一前提现在正受到数学进步和量子计算的威胁，在量子计算中，将大数分解的能力变得明显不那么具有挑战性。如果这些密钥被泄露，使用这些方法的网络上的所有数据和节点都容易受到拦截和网络攻击。量子密钥分发为共享基础物理保证的密钥提供了一种“量子安全”的解决方案。太空为密钥分发提供了理想且高度可扩展的媒介，因为卫星可以在绕轨道飞行时远距离在全球范围内传递密钥。因此，天基量子密钥分发有望补充已经开始出现的地面本地量子密钥分发网络。卫星将为全球地面节点提供这些密钥，以用于现有的电信网络，特别是到偏远地区或跨国际边界。这项工作利用英国和加拿大正在进行的任务发展，将负责即将到来的QKD任务的两个团队聚集在一起：加拿大的QEYSSAT(包括霍尼韦尔和滑铁卢大学)和英国的ROKS(包括Craft Prospect)，以及布里斯托尔大学和斯特拉斯克莱德大学。这项工作将允许英国的QKD技术在QEYSSAT任务中飞行，为该系统提供宝贵的性能数据，并扩展卫星执行另一类QKD链路的能力。它还将允许开发从空间安全分发密钥的新协议，以克服卫星运动造成的挑战和对互操作性的理解，随着现有方法的安全性变得更容易受到挑战和网络攻击，这些协议随时可供采用。

Quantum Key Distribution (QKD) is expected to form a critical part of future secure communications infrastructure. Keys are a highly valuable cryptographic tool for securing valuable and sensitive data. Current key methods protect transactions including mobile telephony, corporate intellectual property, diplomatic cables and financial transactions. The distribution of keys to global communication nodes within a network presents a challenge commonly addressed using computationally hard mathematics, such as calculating the prime factors of large numbers. Security for these keys is therefore based on the premise that the computational cost remain impractically high and expensive relative to the value of the data. This premise is now under threat from mathematical advancement and quantum computing where the ability to factor large numbers becomes significantly less challenging. Should these keys be compromised, all data and nodes on the network using these methods becomes vulnerable to interception and cyberattack.QKD provides a'quantum-safe' solution for sharing keys assured by fundamental physics. Space provides an ideal and highly scalable medium for key distribution, given that a satellite can deliver keys globally over long distances as it flies about an orbit. Space-based QKD is therefore expected to complement ground based local QKD networks which are already beginning to emerge. Satellites will provide these keys to ground nodes globally for use in existing telecommunication networks, particularly to remote locations or across international boundaries.This work leverages ongoing mission developments in the UK and Canada bringing together the two teams responsible for upcoming QKD missions: QEYSSAT in Canada including Honeywell and University of Waterloo, and ROKS in UK including Craft Prospect, and the Universities of Bristol and Strathclyde. The work will allow a UK based QKD technology to fly on the QEYSSAT mission, providing valuable performance data for the system and extending the capabilities of the satellite to perform another class of QKD link. It will additionally allow the development of new protocols for secure key distribution from space overcoming challenges resulting from the motion of the satellitejunderstanding of interoperability, ready for adoption as the security of existing approaches becomes more open to challenge and cyberattack.