Double scroll in a simple `2D' chaotic oscillator

A very simple RC oscillator exhibiting the double-scroll chaotic attractor is described. The circuit contains two opamps, a Wien bridge, and two diodes used as nonlinear devices. The typical waveforms and the phase portraits of the attractor are presented to illustrate the double scroll in a quasi-two-dimensional oscillator     

A feedback strategy to improve the entropy of a chaos-based random bit generator

In this paper, the guidelines to design a true random bit generator (TRBG) circuit with a predefined minimum entropy are discussed. The approach is proposed for a TRBG based on a one-dimensional piecewise-linear chaotic map; it does not require bit throughput reduction, and it is suitable for the development of integrated TRBG circuits. In particular, the proposed design strategy is based on a feedback control procedure that allows to dynamically change the system parameters for the correction of the circuit "nonidealities" (e.g., the circuit offsets). The correction algorithm does not require a direct measurement of the system "nonidealities" or of the effective value of the map parameters, but only a dynamic estimation of these quantities based on the observation of the TRBG output. The design approach is validated by a hardware prototype implemented on a field-programmable analog array. The results of the NIST FIPS 140-2 test suite, the DIEHARD test suite, and the Coron's Universal test, applied to the TRBG output sequences before and after a simple post processing without throughput reduction, are reported and discussed.     

基于单电子器件的蔡氏电路实现

基于提出的单电子晶体管和MOS混合器件构成的非线性电阻电路以及CMOS构建的模拟电感,实现了一种新型蔡氏混沌电路,得到其双涡卷混沌吸引子.研究表明,该混沌电路具有结构简单、功耗较低,实现效果好、集成度高等优点,为混沌电路在理论和实践方面提供了新的硬件基础,同时,也为保密通信领域提供了又一种可行的实现方法.     

Chaos generation in fractional-order switched systems and its digital implementation

A double-scroll chaotic attractor generated by a fractional-order switched system is presented. Based on unstable dissipative systems (UDS) and a switching law, a fractional-order UDS is proposed. Chaos behavior is found with a fractional order as low as 2.568 by satisfying the stability criterion for fractional order chaotic systems. The fractional-order switched system is transformed to an equivalent switched system with augmented states. Then, the equivalent system is straightforward implemented on an ARM system-on-chip board by using Python high level programming language. Numerical simulations are in good agreement with experimental results, which demonstrates the usefulness of proposed method. Additionally, the test 0–1 and a chaos definition for finite state sets are given to demonstrate chaotic behavior. Finally, a random number generator is also proposed as a possible application.     

Design and analysis of multiscroll chaotic attractors from saturated function series

This paper initiates a saturated function series approach for chaos generation. The systematic saturated function series methodology developed here can create multiscroll chaotic attractors from a three-dimensional (3D) linear autonomous system with a simple saturated function series controller, including one-directional n-scroll, two-directional n/spl times/m-grid scroll, and 3-D n/spl times/m/spl times/l-grid scroll chaotic attractors. The dynamical behaviors and chaos generation mechanism of multiscroll systems are further investigated by analyzing the system trajectories. In particular, a two-dimensional (2D) Poincare/spl acute/ return map is rigorously derived for verifying the chaotic behaviors of the double-scroll chaotic attractor, which is a basic generator of various multiscroll chaotic attractors investigated in the paper.     

一种新型双忆阻混沌系统动力学及其电路实现研究

在经典的蔡氏混沌电路基础上,引入三次非线性磁控忆阻模型,利用一个磁控忆阻模型和一个荷控忆阻模型,外加一个负电导替换变形蔡氏电路中的蔡氏二极管,设计了一个五阶混沌电路,用常规的方法研究系统的基本动力学特性。通过数值仿真结果表明电路在参数变化情况下能产生Hopf分岔和反倍周期分岔两种分岔行为,并能产生双涡卷、单涡卷、极限环、同宿轨等不同轨道,出现了双单摆运动。观察混沌吸引子推广到功率与能量信号,观察到蝴蝶翅膀重叠的奇异吸引子。通过改变初始值,能产生共存吸引子和周期极限环共存现象。为了验证电路的混沌行为,将对设计的电路进行了PSpice仿真,电路仿真结果验证了理论分析的正确性。     

Projective Synchronization of Driving–Response Systems and Its Application to Secure Communication

In this paper, we first introduce the model of single-driving double-response system (SDDRS), which consists of a driving system (subsystem) and two response systems (subsystems). By applying the theory of Lyapunov stability, we study the projective synchronization of SDDRS between the driving and response systems. The sufficient conditions for achieving projective synchronization are obtained when the driving system has either a globally stable equilibrium point or a chaotic attractor. Furthermore, we use the SDDRS for cryptography in secure communication and present a novel scheme for encryption and decryption based on its projection synchronization. The results of numerical simulations verify the efficiency of the presented control schemes and the excellence of cryptography.     

N-涡卷超混沌吸引子产生与同步的研究

四阶MCK电路的主要特点是产生双涡卷超混沌吸引子.本文提出在该电路中产生N-涡卷超混沌吸引子的一种新方法.构造一个具有2N-1个分段线性的奇函数,其构造方法是使该函数中的每一个平衡点分别位于相邻两个转折点的正中间,并保持混沌吸引子中涡卷与键带的相互间置,在此基础上利用递推的方法求得该函数中的各个递推参数,从而可在MCK电路中产生N-涡卷超混沌吸引子.基于李雅普诺夫稳定性理论,研究了两个N-涡卷超混沌吸引子的单向耦合同步问题.最后给出了N-涡卷超混沌吸引子产生及其同步的计算机数值模拟结果.     

The Hardware-based PKCS#11 Standard using the RSA Algorithm

In this paper, we have proposed and implemented a hardware-based security system, which executes RSA-based cryptography operations by using the PKCS#11 standard. It was implemented in C, VHDL and FPGAs and it is modular and easily adaptable to the future upgrades for the communication among machines and devices. Any cryptography algorithm can be used; however, in our project we only used the RSA as a case study. We did simulations and real tests that allowed verifying the correct behavior and execution of our project; we used the RSA with keys up to 512 bits. Real tests showed the transmission of ciphered data between our project (PKCS#11 and RSA) and a PC by using serial communication.     

超椭圆曲线密码体制在SET协议中的应用研究

文中介绍了SET协议的运作方式,对超椭圆曲线密码体制和RSA密码体制作了比较,提出了在SET协议中使用基于超椭圆曲线密码体制的的数字签名和数字信封方案,提升了SET协议的安全性和运算速度。     

一种可用于光学密码的安全增强工作模式

 为满足云计算对高安全、高效率密码方案的需求,该文提出一种安全增强密码工作模式——密码反馈“一组一密”(Cipher FeedBack one Block one Key, CFB-BK)模式,并基于数学密码和光学密码组合实现：光学密码对数据分组进行“一组一密”加解密,数学密码利用光学密码密文生成供光学密码下一组数据加解密使用的密钥。安全性分析表明,攻击者在密码学技术范围内,只能采用穷举密钥攻击方式,攻击复杂度高;效率分析表明,比基于数学密码实现的模式效率更高。     

基于Fibonacci-Lucas序列的两种公钥分配密码体制

基于Lucas序列和文献[1]中三阶Fibonacci-Lucas序列提出了两种类似于Diffie-Hellman体制的公钥分配密码体制。     

Halftone visual cryptography.

Visual cryptography encodes a secret binary image (SI) into n shares of random binary patterns. If the shares are xeroxed onto transparencies, the secret image can be visually decoded by superimposing a qualified subset of transparencies, but no secret information can be obtained from the superposition of a forbidden subset. The binary patterns of the n shares, however, have no visual meaning and hinder the objectives of visual cryptography. Extended visual cryptography [1] was proposed recently to construct meaningful binary images as shares using hypergraph colourings, but the visual quality is poor. In this paper, a novel technique named halftone visual cryptography is proposed to achieve visual cryptography via halftoning. Based on the blue-noise dithering principles, the proposed method utilizes the void and cluster algorithm [2] to encode a secret binary image into n halftone shares (images) carrying significant visual information. The simulation shows that the visual quality of the obtained halftone shares are observably better than that attained by any available visual cryptography method known to date.     

三维多涡卷Colpitts混沌系统及其数字硬件实现

基于混沌吸引子形成的机理,利用单位锯齿波函数改造混沌Coipitts振荡器模型,提出了一个新三维多涡卷混沌系统,生成了(2K+1)涡卷混沌吸引子.单位锯齿波函数的引入,增加了系统的指数2平衡点,从而形成多涡卷吸引子.采用常规的动力学分析方法,研究了该多涡卷混沌系统的动力学特性,研究结果表明所提出的系统的Hopf分岔点仅...     

认证的密钥交换协议及SVO逻辑证明

在环境受限的无线通信网络环境中,身份认证和会话密钥的协商是确保通信双方能否建立安全会话的关键。为使认证和密钥建立协议中采用的密码技术能适合受限通信环境中的应用,提出一个基于身份的认证的密钥建立协议,并使用SVO逻辑证明设计协议的安全目标。     

DNA密码中的DNA编码技术

DNA密码是目前新兴的一个前沿研究方向。文章阐述了DNA计算在密码学中几个方面的应用,探讨了DNA编码问题及限制条件,特别是从用DNA计算解决密码学中的一个组合问题的实验步骤中分析了DNA编码的质量,提出了更好的编码。     

高效的无证书短签名方案

无证书密码体制不仅有效地解决了基于身份密码系统中固有的密钥托管问题而且成功地避免了公钥证书的使用,近年来得到了广泛的应用。基于无证书密码系统,提出了一个新的无证书短签名方案,新方案构造简洁、高效,在签名验证阶段仅需2次对运算。方案在随机预言机模型下是可证明安全的,更适于在公开且低带宽的通信环境下应用。     

混沌密码技术在数码防伪中的应用研究

研究了混沌密码技术在数码防伪中的应用。基于混沌密码技术,文中提出了一种新型的混沌密码加解密算法,形成了"双标双码、双向验证"的混沌数码防伪技术,构建了一套可通过短信、网络(Internet、WAP)或现场识别仪查询验证的混沌数码防伪系统,以此验证混沌密码技术在数码防伪领域中应用的有效性和可靠性。     

一种无损多秘密分享视觉密码方案

针对分享多幅秘密图像存在信息损失的问题,该文给出(n, n)无损多秘密分享视觉密码的定义,在此基础上基于环状共享份设计了一种(n, n)多秘密视觉密码方案,使秘密图像的信息损失为零。实验结果表明,该方案不仅实现了在多个参与者之间分享多幅秘密图像,而且秘密图像能够完全恢复。     

用量子效应实现身份认证

利用量子现象对信息进行保密是目前国际量子信息学界和密码学界关注的问题之一．本文利用量子效应实现了网络通信中通信者之间的身份确认．身份确认是密码学中的一个重要课题,本文提出的量子认证协议具有可证明安全性．