When analysing Quantum Key Distribution (QKD) protocols several metrics can be determined, but one of the most important is the Secret Key Rate. The Secret Key Rate is the number of bits per transmission that result in being part of a Secret Key between two parties. There are equations that give the Secret Key Rate, for example, for the BB84 protocol, equation 52 from [1, p.1032] gives the Secret Key Rate for a given Quantum Bit Error Rate (QBER). However, the analysis leading to equations such as these often rely on an Asymptotic approach, where it is assumed that an infinite number of transmissions are sent between the two communicating parties (henceforth denoted as Alice and Bob). In a practical implementation this is obviously impossible. Moreover, some QKD protocols belong to a category called Asymmetric protocols, for which it is significantly more difficult to perform such an analysis. As such, there is currently a lot of investigation into a different approach called the Finite-key regime. Work by Bunandar et al. [2] has produced code that used Semi-Definite Programming to produce lower bounds on the Secret Key Rate of even Asymmetric protocols. Our work looks at devising a novel QKD protocol taking inspiration from both the 3-state version of BB84 [3], and the Twin-Field protocol [4], and then using this code to perform analysis of the new protocol.

翻译：在分析量子密钥分发协议时，可确定多种度量指标，但其中最重要的是密钥率。密钥率是指每轮传输中最终成为双方共享密钥的比特数。存在计算密钥率的方程，例如对于BB84协议，文献[1, p.1032]中第52式给出了给定量子比特误码率下的密钥率。然而，推导此类方程的分析方法通常依赖于渐进假设，即假定通信双方（以下称为爱丽丝和鲍勃）之间传输无限轮次信号。在实际实现中，这显然不可能。此外，某些量子密钥分发协议属于非对称协议类别，对此类协议进行分析难度显著增大。因此，当前大量研究聚焦于称为有限密钥体制的替代方案。Bunandar等人[2]的工作已开发出利用半定规划计算密钥率下界的代码，即使对于非对称协议亦适用。本研究设计了一种新型量子密钥分发协议，该协议既借鉴了3态BB84协议[3]又融合了双场协议[4]的思路，并运用该代码对新协议进行了性能分析。