SPECK算法的不可能差分分析

分析了SPECK2n(2n=64,96,128)算法在不可能差分分析下的安全性。首先利用模加法差分的扩散性质,找到了SPECK2n(2n=64,96,128)算法的7轮不可能差分区分器。其次,基于找到的7轮不可能差分区分器,给出了SPECK64/128算法和SPECK128/256算法的11轮不可能差分分析,以及SPECK 96/144算法的10轮不可能差分分析,恢复了全部主密钥。这是SPECK2n/4n(2n=64,96,128)算法的首个不可能差分分析结果。     

基于背景差分和三帧差分的水下运动目标检测

运动目标检测是计算机视觉中目标跟踪和目标分类的基础,其已经应用于水下机器人执行水下任务和海洋生态研究.水下环境中复杂的场景和不良的照明条件往往使对运动目标的检测变得困难.为了解决上述问题,我们提出了一种将背景差分和三帧差分相结合的方法.在这种方法中,首先,我们分别通过背景差分和三帧差分检测运动物体像素.接下来,我们对背景差分和三帧差分的结果进行"与"运算,背景差分提供了对象的信息,以补充三帧差分检测到的不完整的信息.最后,利用形态学处理来消除背景中由非静态物体引起的噪声.实验结果表明,该方法对从水下视频中运动物体检测,具有可靠并有效的效果.     

拉丁方的差分分布特性研究

研究了2n阶拉丁方的差分密码特性,考察了差分的概率分布和均值以及差分表中各种值的平均数,探讨了这些指标的近似计算问题.采用代数方法得出了2n阶拉丁方的差分表的分布性质,得到了差分值的上界,用概率分析和近似计算方法给出了最大差分的概率分布及其均值、特定差分的概率分布,差分值的平均频数的近似计算公式,并给出了一些具体的实例.实验结果能够用于分组密码中拉丁方的设计与分析,为寻找密码性质优良的拉丁方提供了理论依据.     

改进差分进化算法求解整数任务分配

针对0-1任务规划模型存在维数灾维的问题,提出了一种基于改进差分进化算法的整数任务分配算法。将任务分配的0-1规划模型转化整数规划模型,不仅大幅降低了优化变量的维数,还减小了整式约束条件;将差分进化算法常用的变异算子DE/rand/1/bin和DE/best/2/bin结合起来组成新的变异算子,使得DE既保持了种群的多样性,又有较快的收敛速度和搜索精度,并用改进的差分进化算法求解整数规划;通过典型的任务分配实例验证了该算法在优化大规模任务分配的有效性和快速性。     

流密码Salsa20的差分研究

ECRYPT是欧洲启动的一个为期4年的信息安全项目,它征集了Salsa20,HC256,LEX等34个候选算法。对其中的热门候选算法Salsa20的差分进行了研究,首先给出了有关Salsa20算法中的quarterround函数4个高概率差分,然后分析了Salsa20轮变换的差分分布情况,并给出了一个概率为2^-50的4轮差分路线,最后得出了三个有关Salsa20差分攻击的结论。     

低轮ARIA的不可能差分

不可能差分是对分组密码的一种有效攻击方法.它是寻找不可能出现的差分关系,并排除满足这种关系的密钥,最终恢复出秘密密钥.分析了韩国新型分组密码算法ARIA的不可能差分.首先分析了ARIA混淆层的特性,构造了ARIA的4轮不可能差分,选择225.5个明文对,使其密文异或具有低64b为零的形式,利用4轮不可能差分特性对5轮的ARIA进行了分析.选择230个明文对对6轮ARIA进行分析.     

差分分析方法在HAVAL中的应用

差分分析方法是攻击迭代密码最有效的方法之一,它可以用来攻击任何一个用轮函数迭代的方法构造的密码系统。为此,描述差分分析方法在Hash函数HAVAL-128算法中的应用,并给出选择消息差分、确定差分路径、推导保证差分路径成立的充分条件等方法,诠释了利用差分分析方法攻击Hash函数的理论依据及步骤。     

PRINCE密码算法的差分-线性分析

PRINCE是一个低时延轻量级分组密码算法,广泛应用于各种资源受限设备。PRINCE使用FX结构,其核心部件是 PRINCE_core。差分-线性分析是一种经典分析方法,它将差分分析和线性分析结合起来,使用短的高概率差分特征和线性特征来攻击密码算法。研究了 PRINCE_core的差分-线性分析,使用2轮差分-线性区分器攻击4轮PRINCE_core,需要2⁶个选择明文,时间复杂度为2^14.58次4轮加密。对于 6轮和 7轮 PRINCE_core的差分-线性分析,数据复杂度分别为 2^12.84和 2^29.02个选择明文,时间复杂度分别为2^25.58和2^41.53。     

差分进化算法综述

差分进化算法由于算法结构简单易于执行,并且具有优化效率高、参数设置简单、鲁棒性好等优点,因此差分进化算法吸引了越来越多研究者的关注。本文概述了差分进化算法的基本概念以及存在的问题,综述了差分进化算法的控制参数、差分策略、种群结构以及与其他最优化算法混合等4个方面改进策略并讨论它们各自的优缺点,为差分进化算法下一步的改进提出了参考方向。     

单向差分压力和双向差分压力传感器的测量

在压力测量中,通常是根据测量要求来提出不同的物理测量方法,比如绝对压力、相对压力(表压)和差分压力的测量.然而对于差分压力的测量往往有许多不同的理解.以硅压阻压力传感器AMS 5812为例介绍有关各种压力测量的不同应用情况,同时对硅压阻芯体相关的结构和惠斯顿电桥信号放大作了介绍.     

Solving fuzzy differential equations by differential transformation method

An extension of the differential transformation method (DTM), which is an analytical-numerical method for solving the fuzzy differential equation (FDE), is given. The concept of generalised H-differentiability is used. This concept is based on an enlargement of the class of differentiable fuzzy mappings; to define this, the lateral Hukuhara derivatives are considered. The proposed algorithm is illustrated by numerical examples, and some error comparisons are made with other methods for solving a FDE.     

Time-dependent differential inclusions, cocycle attractors andfuzzy differential equations

Traditional formulations of fuzzy differential equations do not reproduce the rich and varied behavior of crisp differential equations (DEs). A recent interpretation in terms of differential inclusions, expressed level setwise, overcomes this deficiency and opens up for profitable investigation such properties as stability, attraction, periodicity, and the like. This is especially important for investigating continuous systems which are uncertain or incompletely specified. This paper studies attractors of fuzzy DEs in terms of cocycles and encompasses both the time-dependent and autonomous cases     

Evolutionary ciphers against differential power analysis and differential fault analysis

Side channel analysis(SCA) focuses on attacking cryptographic algorithm implementations by collecting leaked information and analyzing the correlation between the leaked and key information in the cryptographic system.Currently,SCA is the main threat to cryptographic implementations,with DPA(differential power analysis) and DFA(differential fault analysis) being two of the most threatening types of SCA.However,the existing countermeasures against DPA and DFA have shortcomings and can hardly protect cipher designs perfectly.Based on a comprehensive analysis of DPA and DFA,this paper proposes a new idea of using an evolutionary cipher(EVOC) against DPAs based on the model proposed by Kocher,and several different new types of DFAs.In fact,an EVOC is a kind of dynamic cipher designing method.Moreover,combined with intelligent searching algorithms and cryptography design policies,EVOCs utilize the dynamic and unpredictable properties of TRNG(a truly random number generator) to ensure cipher design at a high level of security.Therefore,with an EVOC we could design cryptography algorithms with high security to resist mathematical analysis as well as DPAs and DFAs.This paper analyzes and proves the security,efficiency,cost,and original features of EVOCs against DPA and DFA both theoretically and experimentally.Compared with existing countermeasures against SCAs,EVOCs use dynamic non-linear operations to destroy the bases of DPA and DFA.At the algorithm level,EVOCs are more efficient than other resistance methods.Based on the theory and experiments,this paper proposes certain modifications to the EVOC in the AES(advanced encryption standard) algorithm,which can be referenced by other dynamic designs of cryptographic algorithms.     

Solutions of delay differential equations by using differential transform method

Differential transform method (DTM) is extended for delay differential equations. By using DTM, we manage to obtain the numerical, analytical, and exact solutions of both linear and nonlinear equations. In comparison with the existing techniques, the DTM is a reliable method that needs less work and does not require strong assumptions and linearization.     

Multicriterion differential games

Translated from Kibernetika i Sistemnyi Analiz, No. 1, pp. 24–33, January–February, 1994.     

Thrust-vectored differential turns

Differential-turning games played with thrust vectoring as an aid to maneuvering are examined in an extension of the research of a companion paper which reports a study of thrust-vectored maneuvering in energy approximation. The benefits are found to be major when there is a sufficient margin of thrust over weight to permit hover. Families of turning duels between a conventional aircraft and a thrust-vectored opponent are described in a computational example.