量子密钥分发实时处理技术研究

发布时间：2019-06-02 16:14

【摘要】：量子密钥分发系统是量子物理原理在密码学领域获得实用化应用最早的-个研究领域。它分发的密钥具有“绝对安全”的特性,这个特性来源于量子力学中的不可克隆原理和测量塌缩理论,具有很高的军事和民用价值。1991年诞生了世界上第一个QKD系统原型,它只是一个简单的演示系统,由Bennette等人完成。随后出现更为复杂和完善的QKD系统,QKD的通讯距离和密钥生成速率都在不断的提高。QKD系统发展到现在,已经进入到了多用户互联的QKD网络时代,而QKD网络的结构也在不停的优化和升级当中。当今QKD网络的杰出代表有欧洲的SECOQC量子网,日本的东京高速量子网,和中国的全通型量子通话网以及“合肥—六安—舒城”的城域量子通信网络。 QKD系统的发展已经进入了高速(高密钥生成速率)的阶段,应用最新的半导体工艺技术,采用1GHz以上发射频率的激光器,使用探测效率极高的超导探测器,获得成码率更高的QKD系统。QKD系统实时处理的压力在于QKD后处理过程,因为它是QKD系统电子学处理延迟最大的模块。QKD后处理过程是为了消除Alice和Bob密钥的不同和提高安全性采取一系列操作,它包括四个步骤：基矢比对,身份认证,纠错和隐私放大。本文以满足高速QKD系统为目标,重点研究了QKD后处理过程中的实时技术。从实现实时技术的平台方面考虑,随着对QKD系统设备的小型化和便携性需求方面的提高,同时结合近些年发展迅速的Field Programmable Gate Array (FPGA)技术,本文重点研究了基于FPGA的QKD实时处理技术。QKD系统实时处理技术在硬件内的实现具有特定的优势,可以省去QKD设备和电脑通讯的数据带宽压力,充分利用后处理过程中的并行潜力提高处理速度。以QKD系统实时处理技术为主线,本文的研究内容包括：高效快速的纠错算法,高数据吞吐量的身份认证和高速数据交换的经典通道。对于纠错模块,我们设计和实现了两种不同的方案：基于Winnow的快速纠错算法和基于LDPC纠错码的快速纠错算法。其中基于Winnow的纠错算法在纠错效率和速度方面都有不错的表现,是我们目前中低速的QKD系统中成功应用的算法。而基于LDPC纠错码的纠错算法,纠错时候只需要交互一次信息,在传输延迟大的系统实现优势最大,另外它在纠错效率和速度方面都有可以大幅提升的潜力,是后续高速QKD系统中有望广泛采用的算法。基于Winnow的快速纠错算法的采用的基本纠错码是Hamming码,从Winnow的基本思想出发,我们在段长选取,循环次数设置等方面进行优化,并且提出了使用双线性移位寄存器(LFSR)的随机置换方案,可以获得和使用真随机数一样的“打乱”效果。基于LDPC纠错码的快速纠错算法采用QC-LDPC作为校验矩阵,应用半串行解码算法,该算法的算法结构简单,没有复杂的双曲函数运算和乘除运算,适合硬件结构实现,另外该算法相对于传统的BP解码算法可以节省大部分的存储资源。在算法结构方面,我们提出了一个新颖的信息钳位功能函数,实现简单,可以极大的提升纠错性能。对于身份认证模块,我们实现了基于LFSR的Toeplitz矩阵的身份认证方案。QKD系统的最核心特征是它的“绝对安全”性质,基于LFSR的Toeplitz矩阵的身份认证具备“绝对安全”的特性。在模块设计和实现方面,对算法结构做了优化,提高并行度以实现速度的提升。该身份认证算法的实质是高维度的矩阵乘法,分别从优化矩阵乘法行方向和列方向的运算提出了一次并行化结构和二次并行化结构,实现了高度并行化的身份认证计算模块。对于高速数据交互的经典通道,选择USB3.0作为实现高速数据通道的接口总线。该数据通道中需要传输的QKD系统的经典信息包括：基矢比对信息,纠错信息,身份认证码。我们使用Cypress公司生产的FX3芯片作为USB3.0的协议芯片,应用该芯片提供的从FIFO工作模式。设计了相应的固件,在FPGA中设计了硬件接口模块,在PC上设计了客户端程序,实际测试速率达1.79Gbit/s。文针对处于国际前沿的量子保密通讯中的量子密钥分发系统后处理技术进行探索性研究,研究内容包括高效快速的纠错算法,高数据吞吐量的身份认证和高速数据交换的经典通道,其研究成果将直接提升QKD的后处理性能,并成功用于城域量子通信试验示范网,并将在应用在后续的城际高速量子通讯网中。选题不仅具有理论研究价值,而且具有实际应用价值。本论文的主要创新点如下： 1.针对不同密钥生成速率,完成了2种不同的实时纠错方案。对于低速和中速密钥生成速率,基于Winnow纠错算法修改完成了一个适合于FPGA的快速并行设计,并成功应用于城域量子通信试验示范网；对于高速及超高速密钥生成速率,进行了基于LDPC纠错码的快速纠错算法的研究,完成了基于QC-LDPC使用串行解码算法的硬件解码器,能适应于GHz发射频率的QKD系统中。 2.针对QKD的安全性要求,开展了实时身份认证技术的研究,实现了适合于FPGA实现的基于LFSR的Toeplitz矩阵的身份认证方案,该方案具有“绝对安全”和高度并行化的特性,并成功应用于量子保密通讯试验网。 3.针对高速量子密钥分发系统中,大量经典数据实时交互的需求,展开对高速数据通道的研究,完成了基于USB3.0和千兆网构成了高速数据通道,将用于后续的高速量子密钥分发系统中。
[Abstract]:The quantum key distribution system is the first to be used in the field of cryptography in the field of cryptography. The key to which it is distributed has the characteristics of "absolute safety", which is derived from the non-cloning principle in quantum mechanics and the theory of measurement and collapse, and has a high military and civilian value. The first QKD system prototype in the world was born in 1991, and it is just a simple demonstration system. It's done by Bennett et al. The communication distance and key generation rate of the QKD system, QKD, and QKD, which are more complex and perfect, are constantly increasing. The QKD system has been developed to the QKD network era of multi-user interconnection, and the structure of the QKD network is also constantly optimized and upgraded. The outstanding representative of the QKD network is the SECOQC quantum network in Europe, the Tokyo high-speed quantum network in Japan, and the China's all-pass quantum communication network and the "Shuicheng, Liuliang, Hefei" 's metro quantum communication network. The development of the QKD system has entered a high-speed (high-key generation rate) stage, and the latest semiconductor technology is applied, and the high-efficiency superconducting detector is used to obtain the QKD system with higher code rate by using the super-conducting detector with extremely high detection efficiency. The pressure of real-time processing of the QKD system is the post-QKD process, because it is the most delayed mode in the electronic processing of the QKD system. The post-QKD process is a series of actions to eliminate the differences in Alice and Bob's keys and to improve security, which includes four steps: base-to-target, identity authentication, error correction, and privacy In order to meet the high-speed QKD system, this paper focuses on the real-time technology in the post-QKD process. In view of the development of the platform of real-time technology, the QKD real-time processing technology based on FPGA is studied in this paper with the improvement of the miniaturization and the portability requirement of the QKD system equipment, and combining with the field Programmable Gate Array (FPGA) technology developed in recent years. The realization of the QKD system real-time processing technology in the hardware has specific advantages, the data bandwidth pressure of the QKD equipment and the computer communication can be saved, the parallel potential in the post-processing process can be fully utilized to improve the processing speed, Based on the QKD system real-time processing technology, the research contents of this paper are: efficient and fast error correction algorithm, high data throughput identity authentication and high-speed data exchange. We design and implement two different schemes for error correction module: fast error correction algorithm based on Winnow and fast error correction based on LDPC error correction code The error correction algorithm based on Winnow has good performance in error correction efficiency and speed, and is a successful application in the low-speed QKD system at present. And the error correction algorithm based on the LDPC error correction code only needs interactive information at the time of error correction, has the greatest advantage in a system with large transmission delay, and has the potential of greatly improving the error correction efficiency and speed, and is expected to be widely adopted in the subsequent high-speed QKD system. The basic error correction code used in the fast error correction algorithm based on Winnow is the Hamming code. From the basic idea of Winnow, we optimize the selection of the segment length and the number of cycles, and put forward the random setting using the bilinear shift register (LFSR). Alternatively, you can obtain and use the "to upset" Effect. The fast error correction algorithm based on the LDPC is used as the check matrix and the semi-serial decoding algorithm is applied. The algorithm has the advantages of simple structure, no complex hyperbolic function operation and multiplication operation, and is suitable for hardware junction. In addition, the algorithm can save most of the memory with respect to the traditional BP decoding algorithm. In terms of the structure of the algorithm, a novel information clamping function is proposed, which is simple and can be greatly improved. Error performance. For identity authentication module, we realized the body of the Toeplitz matrix based on LFSR The most core feature of the QKD system is its "absolute safety" property, and the identity authentication of the Toeplitz matrix based on the LFSR has the

"absolute safety" . In the aspect of module design and implementation, the structure of the algorithm is optimized, and the parallelism is improved to realize The essence of the identity authentication algorithm is a high-dimensional matrix multiplication, and a parallelization structure and a secondary parallelization structure are proposed from the operation of the optimization matrix multiplication row direction and the column direction, respectively, and the identity recognition of the height parallelization is realized. For the classical channel of high-speed data interaction, the USB 3.0 is selected as the high-speed data. The interface bus of the channel. The classical information of the QKD system to be transmitted in the data channel includes: the base-to-vector comparison information, the error correction letter, Interest, identity authentication code. We use the FX3 chip produced by the Cypress company as the protocol chip of USB 3.0, and apply the F 3 chip provided by the chip from F IFO operation mode. The corresponding firmware is designed. The hardware interface module is designed in the FPGA. The client program is designed on the PC. The actual test rate is up to 1.7. 9 Gbit/ s. The paper explores the post-processing technology of quantum key distribution system in quantum secret communication at the international front, which includes efficient and fast error correction algorithm, high data throughput identity authentication and high speed The classic channel of data exchange, the research results will directly improve the post-processing performance of QKD and successfully used in the Metro quantum communication test demonstration network, and will be applied in the following city in that inter-high-speed quantum communication network, the topic not only has the theoretical research value, but also And has practical application value. The main innovation points of this thesis are as follows:1. The rate of generation of different keys is finished. Two different real-time error correction schemes have been developed. For low-speed and medium-speed key generation rates, a fast and parallel design suitable for FPGA is completed based on Winnow error correction algorithm, and it is successfully applied to the Metro quantum communication test demonstration network; for low-speed and medium-speed key generation rate, On the basis of the high-speed and super-high-speed key generation rate, the fast error correction algorithm based on the LDPC error-correcting code is studied, and the hardware decoder based on the use of the serial decoding algorithm based on the QC-LDPC is completed, which can be adapted to the G. 2. In the QKD system of Hz transmission frequency,2. The research of real-time identity authentication technology is carried out aiming at the safety requirement of QKD, and the identity authentication scheme of the LFSR-based Toeplitz matrix which is suitable for FPGA implementation is realized, and the scheme has the characteristics of high "absolute safety" and high parallelism, in that high-speed quantum key distribution system, a large amount of the requirement of real-time interaction of the classical data and the research of the high-speed data channel are carried out, and a high-speed data channel based on the USB 3.0 and the gigabit network is completed,
【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】：2014
【分类号】：TN918.4

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