光纤量子密码和量子指纹识别研究

发布时间：2018-04-14 20:14

本文选题：量子信息 + 量　；参考：《中国科学技术大学》2017年博士论文

【摘要】：量子信息物理学是基于量子物理的原理来研究信息学的学科,同经典信息学相比,在解决一些问题上有巨大优势。基于量子力学的基本原理可以实现量子密钥分发(QKD),可以理论上无条件安全地进行密钥的扩展,配合一次一密的加密方式,可以实现无条件安全的保密通信。基于量子态叠加干涉的量子指纹比对,可以做到比经典方案更节约信息量。基于量子态测量塌缩原理的量子随机数,可以做到比经典随机数更加安全,理论上是无法预测的。本论文首先介绍一种高度抗信道干扰的新型QKD方案。普通的QKD方案对系统的错误率有着严格的要求,而这种方案可以容忍很高的错误率,理论上可以到50%的极限。之后我们介绍原方案的一些不足,在此基础上,我们提出了该方案的被动式实现,并演示了其高容错率的能力。我们的方案在53 km的距离上,比特错误高达31.2%的时候依然可以成码。这超越了现有的其它QKD协议,有望应用于环境干扰较大的场合。指纹识别是经典信息论中的一个重要内容,为了让Referee判断出Alice和Bob双方的信息是否相同,Alice和Bob只需发送一小段"指纹"数据给Referee。对于经典的n长度的字串做指纹识别,需要发送(?)量级的信息量,而量子态有着相干叠加的性质,n个qubits相干叠加可以有2n个基矢,从而能携带的信息量指数的优于经典比特。亦即,理论上通过log2n量级的qubits就可以完成指纹识别的任务。我们首先介绍了更加实用的相干态量子指纹识别方案,证明其同样拥有指数量级的优势,然后我们进行了远距离的量子指纹识别试验,通过优化各个部分的性能,在20km的距离下实现了优于经典理论极限的指纹识别,是目前量子指纹识别的最远距离,而且是首个超越经典信息理论极限的量子指纹识别实验。随机数产生器也是通信领域用到的关键器件。经典的随机数通常用伪随机数或经典物理随机数的方式产生。前者的安全性依赖于计算复杂度的假设,后者也不能完全证明不被攻击者控制。而量子随机数的产生依赖于量子力学假设,其随机性在量子力学框架下,不受攻击者影响。本论文提出了一种测量设备无关的量子随机数产生器的方案,在保持量子随机数的理论安全性的同时,也关闭了使用现实的探测器可能带来的漏洞,进一步提高了实用环境下的安全性。
[Abstract]:Quantum information physics is based on the principle of quantum physics to study the subject of informatics. Compared with classical informatics, quantum information physics has great advantages in solving some problems.Based on the basic principle of quantum mechanics, the quantum key distribution can be realized, the key can be extended unconditionally and safely in theory, and the secure communication can be realized by using one encryption method at a time.Quantum fingerprint comparison based on quantum state superposition interference can save more information than classical scheme.Quantum random numbers based on the collapse principle of quantum states can be more secure than classical random numbers and can not be predicted theoretically.In this paper, we first introduce a novel QKD scheme with high anti-channel interference.The common QKD scheme has strict requirements for the error rate of the system, and this scheme can tolerate a very high error rate, which can theoretically reach the limit of 50%.Then we introduce some shortcomings of the original scheme, and on this basis, we propose a passive implementation of the scheme, and demonstrate its ability of high fault tolerance.Our scheme can still be coded at a distance of 53 km when the bit error is as high as 31.2%.This goes beyond other existing QKD protocols and is expected to be used in situations where there is greater environmental interference.Fingerprint identification is an important part of classical information theory. In order for Referee to judge whether the information between Alice and Bob is the same or not, it is only necessary to send a little "fingerprint" data to Referee.For the classic n-length string fingerprint identification, you need to send.)The quantum state has the property of coherent superposition. N qubits coherent superposition can have 2n basis vectors, so the information quantity exponent is better than the classical bit.In other words, the task of fingerprint identification can be accomplished by log2n qubits.We first introduce a more practical scheme of quantum fingerprint identification for coherent states, and prove that it also has the advantage of exponential magnitude. Then we conduct a long-distance quantum fingerprint identification experiment to optimize the performance of each part.Fingerprint identification, which is better than the limit of classical theory, is realized at the distance of 20km. It is the farthest distance of quantum fingerprint recognition at present, and it is the first quantum fingerprint identification experiment that surpasses the limit of classical information theory.Random number generator is also a key device used in communication field.Classical random numbers are usually generated by pseudorandom numbers or classical physical random numbers.The security of the former depends on the assumption of computational complexity, and the latter can not be completely proved to be out of the control of the attacker.The generation of quantum random numbers depends on the assumption of quantum mechanics, and its randomness is not affected by the attackers under the framework of quantum mechanics.In this paper, a scheme of measuring device independent quantum random number generator is proposed, which not only keeps the theoretical security of quantum random number, but also closes the loophole that may be brought by using real detector.The security in practical environment is further improved.
【学位授予单位】：中国科学技术大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：O413;TN918

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