量子密钥分发系统和量子随机数发生器

【作者】 冯凯锋；

【导师】 吕述望； 刘振华；

【作者基本信息】 中国科学院研究生院（电子学研究所） ， 通信与信息系统， 2002， 硕士

【摘要】 本文报告了笔者在量子密钥分发实验系统的研究和量子随机数发生器的研制这两个方面完成的工作。文章首先描述了量子密钥分发的原理，并介绍了其理论和实现进展，然后详细介绍了我们的试验系统的原理、结构和实现，并分析了现有系统的存在的问题，最后指出了量子密码技术离实用化的差距。我们自制几乎所有的基本模块，搭建了一个基于BB84协议的量子密钥分发光纤实验系统，其工作波长是850nm，传输距离是1.1km。我完成的主要工作是实现了APD单光子探测器、通信和数据采集模块，并在具体实验时负责电路系统的调整。结合研究过程的切身体会，我提出了对量子密码技术实用化的几点看法。同时，我还负责实现了一个基于单光子的路径选择的随机性的量子随机数发生器，其序列生成速率为40KHZ左右，产生的序列能够通过随机性测试。此设备将用于将来的量子密钥分发系统，经过改进还可能应用到其它领域。更多还原

【Abstract】 During information age, information security, which is now guarded by modern cryptography, always is of great importance for every nation, every group and every body. But with the development of quantum information sciences, maybe modern cryptography is not really secure any more under the attack of quantum computer in future. At the same time, quantum cryptography, based upon Heisenberg’s Uncertainly principle, which guarantees its absolute security.Our Quantum Cryptography research group focuses on developing a fiber optic Quantum Key Distribution (QKD) system based on phase encoded single photons. My work during past two years in this group is reported in this article.Firstly the principle of QKD is introduced, its previous development and prospect is described secondly. Our experimental work is the main part. After the description of the framework of our system, the implementation of its basic modules, including single photon source, single photon detectors, optical fiber phase modulator and data acquisition and processing program, is reported. Our system is based on BB84 protocol. The working wavelength is 850nm and transmission distance is 1.1Km. My own job concentrates on single photon detector, data acquisition and processing program.At the same time, I have implemented a Quantum Random Number Generator based on the intrinsic randomness of quantum mechanics, which will be used in our future QKD systems and can be developed into a kind of product. The random events are realized by the choice of single photons between the two outputs of a beamsplitter. Its byte generation rate is about 40KHZ and the generated byte sequence can pass randomness test.更多还原