Verification of finite size continuous-variable quantum key distribution under coherent attacks

相干攻击下有限尺寸连续变量量子密钥分布验证

• 批准号: 249157115
• 负责人: Professor Dr. Roman Schnabel
• 金额: --
• 依托单位: Institut für Theoretische Physik
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2014
• 资助国家: 德国
• 起止时间: 2013-12-31 至 2016-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/249157115?language=en
• 关键词: Verification; finite; size; continuous; variable

Quantum key distribution (QKD) aims at the distribution of secret information, only known, in the simplest case, to two directly involved parties usually called Alice and Bob. In contrast to classical cryptography, fundamental laws of quantum mechanics ensure that the information, encoded in quantum states, cannot be copied unnoticed. It is widely considered the most mature branch of quantum information science, where even some commercial implementations are available. The aim of this project is to build a quantum cryptography system with entangled laser beams, which improves on earlier work in several significant ways. We will for the first time establish a continuous variable (CV) QKD protocol providing security against most general, coherent attacks. Hence, in contrast to previous CV proposals and realizations, which assess security by an asymptotic formula in terms of the quantum error rate, the new protocol does not require strong additional assumptions constraining the type of attack. The first security proof without such constraints was only recently given by the theory partner of this project. We will exploit record levels of entanglement between twin laser beams, which are only available in the lab of the experimental partner. This is a prerequisite for achieving the demanding criteria set by the new security proof. The aforementioned asymptotic formula only asserts the existence of suitable data processing to generate a key. In most previous experiments the processing step was therefore often taken for granted. We will implement it, thus, generate actual key. The project extends earlier joint work of the two partners, in which a precursor of the planned twin laser beam source was shown to meet the asymptotic security criteria.

量子密钥分发（QKD）的目的是分发秘密信息，在最简单的情况下，只有两个直接参与的方（通常称为Alice和Bob）才知道。与经典密码学不同，量子力学的基本定律确保了以量子态编码的信息不会被复制。它被广泛认为是量子信息科学中最成熟的分支，甚至有一些商业实现。该项目的目的是建立一个量子密码系统与纠缠的激光束，这在几个重要的方面改进了早期的工作。我们将首次建立一个连续变量（CV）QKD协议，提供对大多数一般的，一致的攻击的安全性。因此，与以前的CV提案和实现（通过量子错误率的渐近公式评估安全性）相比，新协议不需要约束攻击类型的强附加假设。第一个没有这种约束的安全证明是最近由该项目的理论合作伙伴给出的。我们将利用双激光束之间的创纪录纠缠水平，这只能在实验伙伴的实验室中获得。这是实现新安全证明所设定的严格标准的先决条件。上述渐近公式仅断言存在用于生成密钥的适当数据处理。因此，在大多数以前的实验中，处理步骤通常被认为是理所当然的。我们将实现它，从而生成实际的密钥。该项目扩展了两个合作伙伴早期的联合工作，其中计划的双激光束源的前体被证明符合渐近安全标准。