Security in a Quantum World

几千年来，密码制造者和密码破译者一直在争夺霸权。我们现在生活在互联网时代，通过加密的数据安全是非常重要的。尽管如此，标准加密方案通常基于未经证实的计算假设，这可能会被硬件（例如大规模量子计算机）或算法的意外进步所打破。原则上，量子密码学可以提供由物理定律保证的无条件安全性。商业量子密钥分配系统正被许多瑞士银行用于加密关键通信。“量子密码学中最重要的问题是确定它到底有多安全。”（布拉萨和克雷波）最近，我们的团队对一个商业量子密钥分发系统进行了全球首次成功的量子黑客攻击，从而凸显了安全漏洞的存在。在本提案中，我们将通过实施我们小组提出的独立于测量设备的量子密钥分发的新思想来消除探测器侧的所有安全漏洞。理论研究、模拟和实验研究相结合。我们的工作不仅将对实际量子密钥分发系统的安全性有更深入的了解，而且还将产生具有无与伦比的安全性和性能的新量子密钥分发系统，并可能孵化出加拿大第一个商业量子密钥分发产品。

For thousands of years, code-makers and code-breakers have been competing for supremacy. We now live in the Internet Age where data security via encryption is of great importance. Nonetheless, standard encryption schemes are often based on unproven computational assumptions, which can be broken by unanticipated advances in hardware (e.g. a large-scale quantum computer) or algorithm. Quantum cryptography can, in principle, provide unconditional security guaranteed by the laws of physics. Commercial quantum key distribution systems are being used by a number of Swiss banks to encrypt critical traffic. "The most important question in quantum cryptography is to determine how secure it really is." (Brassard and Crepeau). Recently, our group has performed the world's first successful quantum hacking against a commercial quantum key distribution system, thus highlighting the existence of security loopholes. In this proposal, among other things, we will remove all security loopholes on the detector side by implementing the novel idea of measurement device independent quantum key distribution, proposed by our group. A combination of theoretical research, simulations and experimental investigation will be performed. Our work will lead to not only a much deeper understanding of the security of practical quantum key distribution systems, but also new quantum key distribution systems with unmatched security and performance and may incubate the first Canadian commercial quantum key distribution product.