利用特定应用可编程逻辑实现密码算法功能的研究

提出了一种基于可重构技术实现多种密码算法功能的设计思想，称这种硬件实现为特定应用可编程逻辑（ASPL），通过对密码算法中相容性运算的分析，提出了ASPL中可重用密码单元与互联网络的设计思想，并对可重用密码单元与互联网络实现的关键技术进行了阐述，最后对ASPL在数据保护方面的应用前景进行了展望。     

针对MUX-LUT混合结构的FPGA工艺映射算法研究

针对具有MUX-LUT混合结构的FPGA芯片，提出一种对其进行工艺映射的面积优化映射算法．该算法的内容包括逻辑门电路到MUX网络的转换方法，MUX网络到FPGA芯片逻辑单元的映射方法．文中算法采用模式匹配的方法除去电路中的冗余MUX，以减少映射结果的面积开销．应用测试电路分别对该算法和Xilinx的Foundation系统对XC4003E芯片的工艺映射结果进行了比较测试，并给出了测试结果。     

基于遗传算法的制造单元重组技术研究

根据生产任务动态重组制造单元是缩小生产设备调度范围，提高机床利用率的一个有效途径，针对制造单元重组问题，提出了基于生物遗传规律的制造单元重组算法（GCRA），该算法真实地反映了动态逻辑单元重组的本质要求，具有模型简单，设计变量少，计算速度快，稳定性强等优点，最后给出了实例验证。     

一种基于BENES网络的可重构比特置换系统设计

采用ATM交换机中的BENES网络,提出了一种简洁正确的寻径算法,在可重构密码芯片上实现比特置换功能单元,能够完成N！种N到N的任意比特置换。该方法可以支持新的密码算法,加速分组密码,减少资源占用。     

基于FPGA可重构快速密码芯片设计

为提高密码芯片的应用效益,提出了一种基于FPGA可重构的密码芯片实现方法。该方法打破了传统了一类密码芯片采用一种设计方案的模式,通过对FPGA的重构设计,能够动态地实现多种不同计算特征的密码算法芯片。同时对最基础的乘法运算和加法运算,设计了细粒度流水的加速策略。该方案能够重构实现DES、AES、RSA、椭圆曲线密码算法等典型密码算法,对600M的数据文件加密测试,DES的加速比为2.8,AES的加速比为3.6。     

针对一种多模式逻辑单元结构FPGA的工艺映射

结合FPGA设计的特点,提出一种可灵活配置的多模式FPGA逻辑单元结构及对其进行工艺映射的工具VMAP.该工具中除了采用一般的工艺映射算法外,还结合逻辑单元结构特点提出了专门的合并优化算法.该算法基于图的最大基数匹配,将部分查找表进行合并,减小了映射结果的面积开销.实验结果表明.对于标准的测试电路,结合文中的逻辑单元结构和合并算法得到的工艺映射结果平均可以减少15.7%的基本逻辑单元使用个数.     

面向分组密码的高速可重构模运算单元设计北大核心CSCD

模运算单元是粗粒度可重构密码阵列(Coarse Grain Reconfigurable Cryptographic Array,CGRCA)的关键部件,通过重构不同处理位宽和模数的算术类密码算子来覆盖更多类型的分组密码,然而现有的模运算单元的执行延迟高且功能覆盖率低,限制了CGRCA整体性能的提升。文章通过分析分组密码模运算特性,提出一种可重构模运算方法,统一了该类算子的数学表达方式,并设计了一种可重构模运算单元(Reconfigurable Modulo Arithmetic Unit,RMAU),该单元支持5种模乘运算、3种模加运算和3种乘法累加运算。同时,通过舍弃部分积中的无用比特位、扩展Wallace树压缩求和过程、精简模修正电路执行路径,降低了该单元的关键路径延迟。基于CMOS 180 nm工艺测试了RMAU的功能与性能,实验结果表明,文章所提的RMAU具备高功能覆盖率,与模乘RCE单元、可扩展模乘结构和RNS乘法器相比,计算延迟分别降低了39%、44%和47%。     

一种用于图像加解密的高效混沌反馈流密码设计

基于混沌的密码算法为发展安全图像加密技术提供了一些新的有效途径。针对这研究问题，本文提出了一种基于混沌的反馈流密码，用于图像密码系统。该方法基于混沌逻辑映射和256位的外部密钥，其机制将密码引入循环行为，使得每个明文像素的加密依赖于密钥、前一个密码像素的值和Logistic映射的输出。文中通过密钥空间分析、统计分析和密钥敏感性测试等大量实验来验证基于混沌反馈流密码算法的有效性，其结果表明本文所提出的基于混沌反馈流密码能够为实时图像加密和传输提供了一种安全高效性的方法。     

概率逻辑公式集分解的合并聚类算法

为使概率逻辑的不确定性推理方法能应用于较大规模的知识库，本文基于一个实际专家系统知识库的开发经验，在概率逻辑公式一致性区间的一般算法基础上，为概率逻辑公式集的分解设计了一种合并聚类算法．对于不同背景的概率逻辑知识库，只要公式集具有一定的分层结构性质，该算法就能保证Ｄａｎｔｚｉｇ－Ｗｏｌｆｅ分解的联合计算模型适用于概率逻辑推理．测试结果表明，该算法对于数１０个变量和子句的实例可收到很好的效果．     

基于模块划分的可重构分组密码芯片设计

针对分组密码算法芯片可重构设计的需求,提出了基于模块划分的可重构设计思想。通过对多种分组密码算法流程及实现过程进行分析和分类,将所有算法功能划分为:固定功能模块和可重构功能模块。在设计相应的可重构互联结构,实现对分组密码算法的可重构设计。通过对多种分组密码算法进行详细设计与测试分析结果表明,采用模块化的可重构设计对单个算法带来的时间延时增加为7%-23%;通过对分组密码算法芯片的交叉测试结果表明,算法用与配置所增加的时间延时为2%-16%,而且随着计算功能最终趋于稳定之后,所增加的配置时间将趋近于2%。     

适用于可编程加密芯片的可重组体系结构

提出了一种适用于可编程加密芯片的可重组体系结构。该体系结构的硬件逻辑电路能够根据不同的应用需求,重新组织,构成不同的电路结构,实现不同的功能,以匹配不同的应用需求。     

可重构密码协处理器的概念及其设计原理

提出了可重构密码协处理器的概念并论述了其设计原理。所谓可重构密码协处理器实际上是一个其内部逻辑电路结构和功能可被灵活改变的密码处理单元,它能够在主处理器的控制和驱动下灵活、快速地实现多种不同的密码操作,以便适应不同密码算法的需求。基于可重构密码协处理器的可重构密码系统具有灵活、快速、安全的特点,在保密通讯和网络安全等领域中具有良好的应用前景。     

Rijndael加密算法在低成本FPGA上的实现

论文介绍了Rijndael加密算法的不同硬件实现方式。为了兼顾硬件资源和电路性能两个方面,根据XilinxFPGA内在的结构特点,设计采用了inner-round流水线结构,利用了FPGA的内置RAM和丰富的寄存器资源,在消耗很少资源的情况下获得了极高的加密速度。     

Grain型级联反馈移存器的非奇异性判定

Grain算法是欧洲序列密码工程eSTREAM最终入选的面向硬件实现的3个序列密码算法之一,它由2个反馈移存器和前馈函数组成,能有效抵御基于线性反馈移存器的序列密码攻击。针对以Grain算法为特例的Grain型级联反馈移存器的非奇异性判定问题,给出Grain型级联反馈移存器在初始化过程和密钥流生成过程中,状态刷新变换均构成双射的充分条件,并通过反例说明对于有限域上的Grain型级联反馈移存器,即使所使用的2个移存器都是非奇异的,并且前馈函数满足相应性质,其状态刷新变换仍可能不构成双射。利用Grain v1算法验证了该非奇异性判定结果的正确性。     

Encryption System with Variable Number of Registers

Encryption in wireless communication systems is an extremely important factor to protect information and prevent fraud. In this paper, we propose a new encryption system for use in stream cipher applications. The design proposed is intended for hardware implementation and based on (n+1) feedback shift registers interconnected in such a way that one register controls the clocking of the other n registers. The aim of this construction is to allow the production of a large family of distinct keystreams when the initial states and feedback functions of the feedback shift registers are unchanged. The produced keystreams are shown to possess the basic security requirements for cryptographic sequences such as long period, high linear complexity and good statistical properties, provided that suitable parameters are chosen. Furthermore, the design is shown to resist various types of cryptanalytic attacks. These characteristics and properties enhance its use as a suitable encryption system for stream cipher applications.     

An efficient cryptosystem Delta for stream cipher applications

The need for wireless communication systems has increased rapidly in the past few years and wireless communication has become more convenient in business and society. However, the air interface is vulnerable to eavesdropping, hence encryption in wireless communication systems is a necessity to keep sensitive information confidential and to prevent fraud. Furthermore, wireless devices such as Bluetooth devices and mobile phones require an encryption algorithm that is secure, fast and simple to implement. There are several cryptosystems for stream cipher applications such as A5/x used in GSM mobile communications. However, A5/x are vulnerable to cryptanalytic attacks. In this paper, a new clock-controlled cryptosystem intended for hardware implementation is proposed. The design has attractive properties such as simplicity and scalability. The cryptographical properties including period, balancedness, linear complexity and probability distribution are analyzed. The design provides the basic security requirements, and is resistant to known cryptanalytic attacks. It is shown that the irregular clocking introduced provides a certain level of strengthened security against several cryptanalytic attacks. These properties enhance its use as a suitable cryptosystem for stream cipher applications.     

Java密码体系结构及中文信息加密技术

电子商务中信息安全的要求，促进了数字签名等技术的研究与发展。Java开发平台提供了丰富的密码服务。文章在描述常用加密算法基础上，分析了Java密码体系结构的组成及应用，并用其实现了对中文信息的加密算法。     

PAPERS DISCLOSE ALLIES' EDGE IN KNOWING GERMAN CODES

Pless has proposed a stream cipher based on J-K flip-flops that uses 8 linear shift registers with feedback, having a combined length of 97 bits, 4 J-K flip-flops, and a 4-stage cycling counter. The cipher has 2.54×10⁵¹ initial states (keys), and generates a presumably pseudorandom stream whose period is 1.52×10²⁹ bits. Despite these impressive statistics, it is computationally feasible to solve such a cipher with a known-plaintext attack, using as few as 15 characters.     

Legged robot locomotion and gymnastics

The learning and control space of real-world autonomous agents are often many-dimensional, growing, and unbounded in nature. Such agents exhibit adaptive, incremental, exploratory, and sometimes explosive learning behaviors. Learning in adaptive neurofuzzy control, however, is often referred to as global training with a large set of random examples and a very low learning rate. This type of controller is not reorganizable; it cannot explain exploratory learning behaviors as exhibited by human and animal species. A theory of coordinated computational intelligence (CCI) is proposed in this paper which leads to a reorganizable multiagent cerebellar architecture for intelligent control. The architecture is based on the hypotheses that (1) a cerebellar system consists of a school of relatively simple and cognitively identifiable semiautonomous neurofuzzy agents; (2) autonomous control is the result of cerebellar agent fine-tuning and coordination rather than complicate computation; and (3) learning is accomplished via individual cerebellar agent learning and coordinated discovery in a learning-tuning-brainstorming process. Agent oriented decomposition and coordination algorithms are introduced; necessary and sufficient conditions are established for cerebellar agent discovery and common sense cerebellar motion law discovery. Nesting, safety, layering, and autonomy-four principles are analytically formulated for the reorganization of neurofuzzy agents.     

An Efficient Block Encryption Cipher Based on Chaotic Maps for Secure Multimedia Applications

ABSTRACT

This paper presents an efficient chaotic-based block encryption cipher (CBBEC), which is a symmetric encryption algorithm designed with the potential of increasing security and improving performance. It is a hybrid mixture from chaos theory and cryptography. Its salient features include the use of eight working registers providing capability to handle 256-bits plaintext/ciphertext block sizes, employing a chaotic logistic map in key scheduling to generate session key used in encryption/decryption, the essential heavy use of data-dependent rotations and the inclusion of integer multiplication as an additional primitive operation. The use of multiplication with eight working registers greatly increases the diffusion achieved per round, allowing for greater security, fewer rounds and increased throughput. Comparative performance evaluation of the proposed chaotic-based block encryption cipher CBBEC with Rijndael, RC6 and RC5 is addressed. Experimental results show that the proposed CBBEC is a fast block cipher, showing its great potential in real-time encryption applications.