基于混沌激光的多位物理随机数高速产生技术研究

发布时间：2018-03-21 18:47

本文选题：物理随机数　切入点：混沌激光　出处：《太原理工大学》2017年硕士论文　论文类型：学位论文

【摘要】：随机数在科学计算、身份识别、雷达测距、信息安全等领域有着广泛而重要的应用。特别是在保密通信中,随机数作为密钥对明文信息进行加密,其可靠性关系到国家安全、商业金融、个人隐私等诸多方面。根据信息论鼻祖香农提出的"一次一密"理论,要保障通信的绝对安全,首先须产生不低于通信速率的真随机数。通常,以产生方式的不同将随机数划分为两大类——伪随机数和物理随机数。基于算法产生的伪随机数速率可达数十Gbps,但是其固有周期性令它无法满足绝对保密通信的要求。自然界中无规律的物理随机现象具有不可重复及不可预测的特性,是提取真正安全随机数(物理随机数)的理想熵源。已有物理随机数产品所使用的熵源包括单光子、电阻热噪声、散弹噪声、混沌电路、振荡器抖动等。然而,上述物理熵源的带宽处于MHz水平,导致其产生的随机数速率受限于Mbps量级,与当前高速通信速率相去甚远。混沌激光是一种具有宽频谱特性的复杂信号,信号强度在时域上呈现强烈的随机起伏变化,适用于高速物理随机数的产生。目前,基于混沌激光的随机数产生技术普遍是利用光电探测器先将混沌激光转化为电信号,而后在电域中由电时钟驱动模数转换器(ADC)对混沌电信号进行采样、量化,结合后处理逻辑器件进一步完成随机数速率的提高和性能的优化。大量理论证明显示,采用这种技术产生的物理随机数等效理论速率可达Tbps量级。然而,必须注意到的是,在实际实现过程中,受限于电时钟的"电子抖动速率瓶颈",基于混沌激光的物理随机数实时产生速率尚未突破5 Gbps。针对这一问题,我们提出全光采样混沌激光结合多位比较量化的技术方案来产生高速物理随机数。具体地,在全光域完成混沌激光的采样过程,以主动锁模激光器输出的超短光脉冲作为控制时钟光,触发太赫兹光非对称解复用器(TOAD)结构的全光采样门,在时钟到达时刻采样混沌信号光,使连续的混沌信号光转化为等间隔的混沌光脉冲序列。继而,采用多位比较器(等同于不含"采样-保持"电路的多位ADC)对采样后的混沌脉冲进行量化,通过合理选取量化结果的最低有效位数,可直接产生优质物理随机数。本方法无需复杂的逻辑后处理过程,所得物理随机数速率由光采样率和所取量化结果有效位数的乘积决定。对于上述方案中的关键技术问题,进行了如下研究工作:1.为了优化混沌激光熵源特性以产生高质量的物理随机数,实验分析了抑制混沌激光时延特征的关键参数,确定了单腔反馈半导体激光器结构产生混沌激光的最优参数空间。进一步,构建了单反馈混沌激光注入从激光器结构,实验产生了超宽带、无时延特征的混沌激光。2.搭建了 TOAD全光采样实验系统。通过探究大窗口及小窗口情况下的采样状态,确定了采样窗口宽度的优选范围。实验上对不同波长的信号光进行采样,证实了采样门良好的稳定性和高线性度。基于实验获取的TOAD最佳特性参数,分别实现了对带宽6 GHz、11.9 GHz混沌激光的5 GSa/s、10GSa/s实时光采样。3.基于以上实验研究,对超宽带混沌激光发生装置、TOAD全光采样系统进行了集成,设计制作了混沌激光源及全光采样器两台样机。4.构建基于重对数定律和中心极限定理的数学模型,分析了混沌激光产生随机数的布朗运动特性。结果显示,基于多位比较量化技术由混沌激光中提取的物理随机数可完美仿真布朗运动,证明了其具有非确定性。5.探究了多位比较量化技术中,最低有效位选取对所得随机数质量的影响。实验中以8位比较器量化重频5 GHz的混沌脉冲序列,选取量化结果最低有效位4位,产生了速率20 Gbps的优质物理随机数。
[Abstract]:Random number in scientific computing, identification, radar, information security and other fields has been widely used in secure communication. Especially, the random number as the key to encrypt the plaintext information, its reliability is related to national security, commercial finance, personal privacy and other aspects. According to the information on the originator of Shannon the "one-time" theory, to ensure the absolute safety of the communication, we must first generate true random number is not lower than the rate of communication. Usually, the different ways to generate random number will be divided into two categories: pseudo random number and physical random number. The pseudo random number generation algorithm speeds up to dozens of Gbps based, but the natural period makes it absolutely can not meet the requirements of secure communication. The phenomenon of physical random irregular in nature can not be repeated and unpredictable characteristics, is the extraction of real security (physical random random number The number of) the ideal entropy source. By using the entropy of physical random number of products including single photon, thermal noise, shot noise, chaotic oscillator circuit, jitter. However, the physical entropy source bandwidth at MHz level, resulting in the random number rate is limited to Mbps level, and the current high speed communication the rate of far. Chaotic laser is a complex signal with a wide spectrum of the signal strength has a strong random fluctuation in the time domain, suitable for high speed physical random number generation. At present, the random number generator based on chaotic laser technology is generally using photoelectric detector first chaotic laser is converted into an electrical signal driving module converter by electric clocks and in the electrical domain (ADC) sampling of chaotic signal quantization, combined with postprocessing logic device further improve performance and random rate optimization. A lot of theory Show, produced by the technology of physical random equivalent theoretical rate reached the level of Tbps. However, it must be noticed that, in the actual implementation process, due to the electric clock "jitter rate bottleneck", real time production rate has not reached 5 Gbps. in order to solve the problem of physical random number based on chaos laser, we put forward the technological scheme of all-optical sampling chaotic laser combined with a number of quantitative comparison to generate high physical random number. Specifically, complete the sampling process of chaotic laser in the optical domain, with ultra short pulse laser output mode lock as control clock trigger light, terahertz optical asymmetric demultiplexer (TOAD) all-optical sampling gate structure the arrival time of sampling, the chaotic signal in optical clock, the continuous chaotic signal light into the chaotic light pulse interval. Then, the number of comparators (equivalent to excluding mining - maintain "a number of ADC circuit) to quantify the chaotic pulse after sampling, the minimum effective number of reasonable selection of quantitative results, can produce high quality physical random number directly. This method does not need complex logic postprocessing process, the physical random number rate is determined by optical sampling rate and quantization results taken effective bits the product for the key technical problems in the above scheme, carried out research work as follows: 1. the physical random number in order to optimize the properties of chaotic laser source to produce high quality entropy, the experimental analysis of the key parameters of chaotic laser delay feature suppression, to determine the optimal parameter space feedback semiconductor laser structure of chaotic laser single cavity. Further, to build a single feedback laser injected from the laser structure, experimental generation of ultra wideband, chaotic laser.2. without delay characteristics of the built TOAD all-optical sampling testing system Through the sampling state inquiry window and small window case, determine the preferred range of sampling window width. The signals of different wavelengths of light sampling, sampling confirmed the stability of the door and good linearity. The optimal TOAD parameters is obtained based on, were realized on the bandwidth of 6 GHz, 11.9 GHz chaotic laser 5 GSa/s, based on the above experimental research.3. 10GSa/s real time sampling, the ultra wideband chaotic laser device, TOAD optical sampling systems are integrated to design chaotic laser source and optical sampler two kind of machine.4. constructs the mathematical model of iterated logarithm law and the central limit theorem based on the analysis of the Brown movement the characteristics of chaotic laser generated random number. The results showed that the physical random number more than quantitative comparison of extraction technology by chaotic laser in perfect simulation based on Brown movement, it is proved that Non deterministic.5. explores many quantitative techniques, the lowest effective bit selection effects on the quality of random numbers. Chaotic pulse sequence in Experiment 8 comparator quantization repetition frequency is 5 GHz, select the quantitative results of the lowest effective bit 4, the physical quality rate of 20 Gbps random number.

【学位授予单位】：太原理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN24;TN918

【相似文献】