共查询到19条相似文献,搜索用时 140 毫秒
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提出一种基于混沌序列的彩色图像加密算法。该算法首先应用二维Logistic混沌系统产生2个混沌序列,利用对2个混沌序列进行排序产生的2个编号序列对彩色图像进行位置的置乱,然后应用三维Lorenz混沌系统产生的混沌序列中各值进行大小排序,用以引导对置乱后的彩色图像进行像素点的R,G,B值的置换操作,从而实现对颜色的加密。实验结果表明,该算法具有密钥空间大、安全性高和保密性好的特点。 相似文献
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廖琪男 《微电子学与计算机》2011,28(3)
为了实现对数字图像信息的有效保护,提出了一种基于Lorenz混沌序列和类似CBC模式的图像加密算法.首先对Lorenz系统输出的三维混沌序列进行改进,使其具有理想的伪随机特性.然后,根据这三维序列移位图像的像素位置.将图像分块,根据这三维序列和CBC模式改变每一块的像素值,从而实现图像加密;解密时,给出一种基于邻域相邻像素特性的加密图像抗剪切攻击恢复算法.最后应用评价指标对加解密效果和安全性进行分析. 相似文献
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以Chua系统为典型实例,利用数字化处理技术,对其连续时间混沌系统的状态方程进行离散化。基于FPGA实验平台中的DSP Buitder技术,设计了Chua系统的MDL源文件,阐述了用FPGA技术产生Chua混沌吸引子的设计原理、方法与实验步骤。在此基础上进行了电路实验,给出了硬件实验结果,证实了数值仿真与硬件实验结果的一致性。该方法还可适用于在广义Lorenz系统族中产生混沌吸引子。 相似文献
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基于Lorenz系统切换混沌同步的保密通讯 总被引:3,自引:0,他引:3
该文提出利用Lorenz系统切换混沌同步实施保密通讯的方法。构建了有一定关联的两个Lorenz混沌系统,并通过选择器在系统间随机切换;用同一种控制方法既能实现不同Lorenz系统的混沌同步,又能实现相同Lorenz系统的混沌同步;发送系统可以在Lorenz混沌系统间随机转换,传输信道中混沌调制信号也随之不断变化;接收系统将混沌调制信号解调后,即可获取有用信号。由于发送系统的可选择性,导致保密信号的多样性和随机性,因此该保密通讯方法具有更好的保密性能。 相似文献
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混沌伪随机序列生成算法研究 总被引:1,自引:0,他引:1
对常见的一维Logistic混沌系统的伪随机序列的产生方法原理进行了研究,然后采用NISTSP800—22测试标准对几种典型的一维混沌伪随机生成方法进行了随机性测试分析。测试结果显示,一些被大量采用量化算法均存在一些安全缺陷,为混沌在信息安全中的应用提供了指导。最后提出了若干使用Logistic混沌系统的建议,以提高系统的安全性。 相似文献
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一类混沌映射扩频序列的研究 总被引:2,自引:0,他引:2
Logistic混沌映射可产生用于扩频系统的跳频序列。该文用Logistic映射构造了一个二维混沌映射,证明了该二维混沌映射轨道点的概率密度分布,提出了一种混沌跳频序列的产生方法,并通过数值仿真分析了此类扩频序列的奇、偶相关特性和序列码的平衡特性.结果表明:该混沌跳频序列具有良好的性能。 相似文献
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This paper presents the digital implementation of fractional-order (FO) chaotic systems on Field Programmable Gate Array (FPGA). In the proposed work Simulink model of each chaotic system is first realized using HDL coder of MATLAB, wherein each coefficient and signal is represented using a fixed number of bits. The construced design is translated into VHDL code using hardware generation block. This code is further translated into bitstream file using Quartus software. The chaotic system is implemented by downloading the obtained bitstream file into Altera FPGA Cyclone IV E (EP4CE11529C7N) chip. A methodology has been developed to construct FO chaotic system using HDL coder. Five different FO chaotic systems, viz., Lorenz, Chen, Lü, Arneodo, and Lorenz Hyperchaotic system have been presented in the paper to illustrate the methodology. The systems have been implemented on FPGA platform. Analysis of each chaotic system is carried out on the basis of hardware resource utilization, static power analysis and synthesis frequency on FPGA. The results show that FPGA provides high-speed realizations with the desired accuracy and low power consumption for FO chaotic systems. 相似文献
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在Lorenz混沌系统的基础上,加入周期策动力信号形成一种变形的Lorenz系统。利用广义哈密顿系统理论的梅尔尼科夫方法,证明变形Lorenz系统具有Smale马蹄变换意义下的混沌。利用功率谱、Lyapunov指数谱、庞卡莱映射等分析方法,进一步证明了变形Lorenz系统具有混沌系统的运动规律。变形Loren系统主要具有混沌态和类周期态两种状态。当系统处在一个临界状态,系统参数的微小变化就可以引起系统状态的性质变化,使最大Lyapunov指数由正变负。仿真实验表明该混沌系统对微弱周期信号非常敏感,同时对噪声具有极强的免疫力,这种性质使得混沌系统具有检测小信号的潜力,可以实现强噪声背景下弱周期信号有效的自动检测。变形Lorenz系统信噪比工作门限可达到-29dB,进一步优化系统参数,还可以继续降低信噪比下限。 相似文献
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分析了单模激光Lorenz系统和新系统的动力学特性.基于非线性反馈控制器的设计,利用跟踪控制使处于混沌和超混沌的两系统之间的拓扑不等价的异结构混沌系统成功地达到了混沌同步,依据线性稳定性理论分析,确定了控制系统的稳定性.数值模拟表明,通过适当地选择反馈增益系数,响应系统得到了有效控制.由于控制过程中无需计算Lyapunov指数,异结构混沌系统间的拓扑结构亦可以有较大差异,可降低混沌控制工作量和提高保密通信的性能. 相似文献
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基于复杂非线性系统的相空间重构理论和神经网络本质为非线性映射关系的特点,提出利用混沌时间序列重构相空间和BP神经网络构建其预测模型的方法。利用该方法对典型的Lorenz混沌时间序列进行了空间重构,研究了预测模型的预测效果,结果表明单步预测效果理想,多步预测在50步以内也能取得较小的预测误差,证明了混沌信号不同于随机噪声,具有短期可预测、长期不可预测的特征。该方法为具有混沌特性的时间序列如心电信号、电力负荷等预测模型的建立提供了理论基础。 相似文献
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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. 相似文献
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Edward Lorenz was an early pioneer of the chaos theory. He discovered that small changes in initial conditions produce large changes in long-term outcome, and introduced a chaotic attractor already known as Lorenz chaotic oscillator, which produces a butterfly-like behavior. This and all kinds of continuous-time chaotic oscillators can be simulated with different numerical methods. However, a bad choice of the step size and/or parameters of the mathematical models can produce errors or even mitigate the chaotic behavior. These issues are related to the main property of chaotic oscillators, the high sensitivity to the initial conditions, which is quantified by evaluating the maximum Lyapunov exponent (MLE). The Lorenz and other representative oscillators like Lü, Chua's circuit and Rössler have been implemented using different discrete electronic devices and few ones with integrated circuits (IC) using CMOS technologies. Designing CMOS chaotic oscillators is challenging because a very small variation in their parameters from their mathematical models or in the sizes of the MOS transistors may suppress the chaotic behavior. This article describes how to perform a successful simulation and optimization, and how to synthesize the mathematical models using CMOS technology. The application of metaheuristics to optimize MLE by varying the parameters of the oscillators, and the optimization of the CMOS IC design to guarantee robustness to process, voltage and temperature (PVT) variations, are discussed. Finally, we discuss issues on the application of chaos generators in random number generators, robotics and chaotic secure communication systems. 相似文献