一类钟控组合生成器的符合率

给出3个停走生成器在模2加组合方式下符合率的有关结论。此类生成器的输出序列与相应停走生成器的控制序列相互独立;输出序列与相应停走生成器的目标LFSR输出序列不独立,本文对输出序列与目标LFSR序列的符合率进行了讨论,给出有限维联合分布的计算公式。     

扩散输出序列的构造与分析

基于钟控、缩减生成器的构造思想,结合个别元素控制扩大输出的方式构造了一种新型伪随机序列生成器—扩散输出生成器。分析得到其生成序列—扩散输出序列的周期、线性复杂度及游程分布。文中进一步改变扩散输出组,得到一组伪随机序列,分析得到相应序列的周期和线性复杂度,实现对扩散输出生成器的拓展.     

多值“加法型”组合生成器分析

文中运用信息论原理对多值“加法型”组合生成器序列进行分析，得到钟控序列与输出序列的互信息为零的结论，证明了钟控输入与输出序列之间互信息是输出序列长度的严格递增函数，进而对控选逻辑序列设计进行分析。     

随机数发生器检测与设计

随机数常作为密钥、初始化向量或密码协议中的时变参数,在密码应用中起到非常重要的作用。根据密码应用对随机性的要求,随机数生成器的输出序列必须满足随机性和不可预测性要求。文中分析了随机数生成器和伪随机数生成器两种生成器模型,给出了常用的随机性检测方法,以及可能的安全攻击方法,最后提出了一种随机性检测新方法。该方法基于输出样本的每比特的信息熵估计,可用于随机数发生器设计过程中的随机性评估。     

一类“停走”生成器输出序列的若干概率性质

“停走”生成器是由两个线性反馈移位寄存器（LFSR）组成的一个钟控序列生成器，对此概率模型，在LFSR输出序列较一般的假设条件，讨论了“停走”生成器输出序列的若干概率性质，推广了已有文献中的结果。     

采样序列的分析

钟控生成器是一种重要的密钥流生成器,它产生的钟控序列具有较好的复杂度和较强的伪随机性质。目前提出的钟控模型大多是基于序列的相互控制,对输入序列进行采样,而且经常是一类非均匀采样序列,要研究其性质,就必须对采样序列进行分析。丈中分析了采出序列的周期和线性复杂性与被采序列的周期和线性复杂性之间的关系,并以A5／1算法为例,分析变形后的A5／1算法的输出序列的周期和线性复杂度。     

二维缩控生成器的构造与分析

论文基于三元伪随机序列,将钟控生成器和缩减生成器结合进行二维输出,构成一种新型伪随机序列生成器—二维缩控生成器,由其生成的二维缩控序列具有大周期和高线性复杂度,能够抵抗诸如B-M算法等综合算法攻击,且证明了序列游程长度为1或2,数据率为8/9,符号分布基本平衡等性质。因此,二维缩控生成器适合在流密码系统中应用。     

一种新的GF（q）上的广义自缩生成器

设计了一种新的GF(q)上的广义自缩生成器,该生成器的主要特点在于输出方式不同于原生成器。研究表明生成的大序列族有良好的互相关性、均衡性,并且给出了最小周期的下界。同时也指出该序列有丰富的群结构和线性空间结构。     

带记忆多值组合生成器的相关免疫性

考察带l位记忆多值组合生成器输入序列和输出序列的相关免疫性以及k阶相关免疫组合函数的构造。     

联合的F-FCSR密钥流生成器

 在分析带进位反馈移位寄存器(FCSR)的滤波密钥流生成器族F-FCSR线性弱点和其硬件方案F-FCSR-Hv2被攻破原因基础之上,提出了利用两个F-FCSR输出简单非线性运算而成的联合的F-FCSR密钥流生成器.该生成器避免了利用该种情况而进行的Hell-Johansson攻击,其生成序列通过了美国技术与标准局(NIST)STS的16项随机性测试,有高的复杂度,且能抵抗相关攻击和代数攻击.     

一类基于时变逻辑的序列发生器

基于带记忆组合逻辑的序列发生器虽然抗传统的相关攻击,但易受线性时序电路逼近攻击.结合表更新的思想,本文给出了一类基于时变逻辑的序列发生器模型,并分析了输入输出间的相关性等密码学性质.许多密码体制都可归于此种模型,该模型对设计序列发生器有借鉴意义.     

Logistic chaotic sequence generator based on physical unclonable function

Logistic nonlinear chaotic system has many good characters such as initial value sensitivity and topological mixing in the some parameter condition,which is used to create the random sequence signal generator.Because of the attributions of randomness and uniqueness even under the exact,the same circuit layouts and manufacturing procedures,there is still an instinct unclonable difference in each integrated circuit.Therefore,a new sequence stream generator was proposed based on Logistic chaotic system and physical unclonable function designed by double output look-up-table (LUT).The output of the Logistic sequence generator was associated with a specific physical circuit.This kind of sequence generator could resist an attack such as the replication of the keys of the system.The system was designed and tested on the Xilinx FPGA board.The results show that the same architecture of the circuit and the same config file operated on the different FPGA developing board can generate the total different random chaotic sequence stream and improve the randomness of the stream.     

Linear models for a time-variant permutation generator

A keystream generator, known as RC4, consisting of a permutation table that slowly varies in time under the control of itself, is analyzed by the linear model approach. The objective is to find linear relations among the keystream bits that hold with probability different from one half by using the linear sequential circuit approximation method. To estimate the corresponding correlation coefficients, some interesting correlation properties of random Boolean functions are derived. It is thus shown that the second binary derivative of the least significant hit output sequence is correlated to 1 with the correlation coefficient close to 15·2^-3n where n is the variable word size of RC4. The output sequence length required for the linear statistical weakness detection is then around 64ⁿ/225. The result can be used to distinguish RC4 from other keystream generators and to determine the unknown parameter n, as well as for the plaintext uncertainty reduction if n is small     

一种无记忆的真随机数发生器

基于传统的振荡采样电路,设计了一种无记忆的真随机数发生器,从理论上保证了输出是相互独立的.采用弹性函数作为后处理,以较小的硬件代价改善了随机数的统计性能.用纯数字电路在FPGA平台上实现,并验证了该真随机数发生器的性能.测试结果表明该真随机数发生器具有较高的数据输出率和良好的统计特性,适合应用于密码系统中.     

基于FPGA的Lorenz混沌序列的设计及统计测试

硬件加密及混沌算法的应用在信息安全领域中有重要的意义.这里以一种实际应用中常用的Lorenz混沌系统为例,介绍了利用FPGA技术实现该混沌序列的一种物理生成方法,并介绍了衡量此随机比特生成器质量的统计测试方法,这不同于以往的普通序列测试.通过统计测试实验表明,此随机比特生成器所生成的四个序列中x序列的统计特性没有其它三个序列好,在实际运用中应加以注意.可见统计测试在随机比特生成器的质量验证中有着很为必要的作用.     

用于钙离子光频标的高性能脉冲时序产生方法

在钙离子光频标实验研究中,为了保证钟跃迁谱线的测量精度和光频标的锁定精度,方便自动控制实验进程,研究了基于LabVIEW的数字波形法结合数据采集卡产生多通道脉冲信号的方法。该方法采用多路数字信号序列同步输出的方法,由板卡的板载硬件时钟源作为定时器,通过编程从计数器/定时器输出频率连续的矩形脉冲输入到采集卡作为控制各路数字波形输出的同步时钟,数字信号输出过程的数字通道样本输出率可达0.4MHz,脉冲宽度的精度可稳定达到2.5µs,上升延迟小于50ns,而且多路脉冲都以同一个计时起点开始,因此具有很好的分辨率、同步性和稳定性。     

Adaptive fuzzy frequency hopper

An adaptive fuzzy system generates the frequency hopping sequence for a spread spectrum communications system. The system learns rules from data and acts as a pseudorandom number generator. The IMSL uniform random number generator gives training samples. An adaptive scheme learns associations between previous samples and the current sample and encodes these as fuzzy rules. The output fuzzy set for each rule acts as a conditional probability density function. The if-part of the rule states the conditions. At each step thirty prior outputs, scanned according to a fixed sampling pattern, give a new sample distribution x _k. The vector x_k partially matches the if-part distribution of a fuzzy rule and partially fires that rule's output fuzzy set. With the estimated output fuzzy sets the fuzzy system computes the conditional density p_Y|X(y|x_k) for input field X and output field Y. Defuzzification yields the next number in the frequency hopping sequence. The rules, sampling pattern, and initial conditions fix the output sequence. An eavesdropper who did not know all three could not predict the sequence. This fuzzy system can generate a sequence uniform over any number of frequencies. We tested the fuzzy system with 100 and 1025 frequencies and compared it to a shift register with linear feedback. The fuzzy system had lower chi-squared values and thus gave a more uniform or more “random” spread than did the shift register. The fuzzy system was easier to change and harder to intercept     

一种高效微带型光导开关超短电脉冲产生器

本文提出了一种新型高效率微带型光导开关超短电脉冲产生器的电路结构，从理论上分析了光导开关对输出电脉冲瞬时特性的影响，并给出了实验结果。