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1.
A novel image encryption algorithm that based on Erbium-doped fiber laser with an optical delay feedback (ODF-EDFL) system is proposed in this paper. First, by the dynamic analysis of this system, two different chaotic sequences are generated. Meanwhile, the statistic characteristic is verified on this chaotic sequence. On this basis, the image encryption algorithm is designed by using this chaotic sequence: the gray value of the original image is substituted with the chaotic sequence at beginning; then the space array of the image's pixel is mixed up by using both two chaotic sequences. The experimental results show that the proposed method can encrypt digital images quickly and effectively. 相似文献
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Parameters Estimation of Chaotic Telemetry System between Two Different Time-delayed Chaotic Systems
WEI Heng-dong 《电讯技术》2013,53(5)
针对混沌遥测系统的参数估计问题,研究了基于混沌同步的不同混沌时延系统的
参数估计方法。构造了利用不同混沌系统进行参数估计的自适应方案,利用Krasovskii
-Lyapunov理论推导出两个不同混沌时延系统同步和参数估计的充分条件。所提方案应用到
混沌遥测系统参数估计可以有效估计系统参数。非合作者可用所构造方法利用不同混沌
系统获取混沌遥测系统的有用信息。仿真分析验证了方案的有效性。 相似文献
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视频在网络传输过程中需要利用密码进行加密以获得数据的保密性。针对视频存在数据量大和实时性强的特点,提出了一种双混沌自同步流密码算法,以提升加密视频的安全性能和加密效率。密码算法由两个离散时间混沌系统构成:首先,采用混沌反控制方法设计两个三维离散时间混沌系统;然后,将第一个混沌系统的状态变量作为第二个混沌系统的反控制器;最后,将第二个混沌系统迭代产生的状态变量与明文信息进行加密操作。该算法能够有效抵御选择密文攻击与分别征服攻击,具备良好的安全性能。实验测试表明,算法能够达到每秒25帧以上的实时性能,具有良好的加密效率。 相似文献
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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。 相似文献
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利用非线性函数控制的混沌异结构同步 总被引:1,自引:1,他引:0
万志超 《微电子学与计算机》2008,25(4):52-55
研究了利用非线性函数控制的混沌异结构同步问题.基于Lyapunov稳定性理论,设计了非线性控制函数,使得同步误差系统的Lyapunov函数的形式为V(e)=eTPe(P为正定矩阵),根据数学公式推导,理论证明了该方法可以实现不同混沌系统之间的异结构同步.数值模拟进一步验证了所提出方案的有效性. 相似文献
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针对单级混沌通信系统安全度不高的局限性的情况,提出一种用环形蔡氏电路实现多级混沌调制的保密通信系统方案.该方案的主要特点是首先,采用多级混沌调制,提高了整个系统的安全性能;其次,环形蔡氏电路具有两个独立可调的分岔参数电阻,起到了密钥参数的作用,进一步增加了对信号破译的难度. 相似文献
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Tam W.M. Lau F.C.M. Tse C.K. 《IEEE transactions on circuits and systems. I, Regular papers》2004,51(9):1868-1878
In this paper, a multiple access (MA) technique is proposed for chaos-based communication systems, in which chaotic reference signals are transmitted followed by the information-bearing signals. Chaotic reference signals modulated by a binary training sequence are sent periodically. The same chaotic signals are then modulated by the binary data and transmitted. To achieve MA, different chaotic signals and training sequences are assigned to different users. Two types of receivers are proposed. For the first one, an adaptive filter is employed which aims to reduce the inter-user interference. For the second receiver type, a simple inverse-and-average method is used in an attempt to recover the chaotic reference signal, which is then used to correlate with the information-bearing signals for determining the received symbols. The performance bounds of these two schemes are also derived. Finally, the bit error rates of the proposed system are simulated and compared. 相似文献
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分析了Liu混沌系统的特性,讨论了一种观测器同步设计方法.首先对响应系统状态进行重构,然后通过极点配置方法,实现两个混沌系统的状态渐进同步,并通过数值仿真对理论分析加以验证.提出利用Liu混沌系统同步进行图像保密通信的方法,在发送端利用Liu混沌信号掩盖坐标变换后的数字图像信号,在接收端能准确地恢复原始图像信号.仿真结果表明了提出的图像保密通信方法具有很好的保密性. 相似文献
11.
本文指出"混沌非线性反馈密码序列的理论设计和有限精度实现"和"一类新型混沌反馈密码序列的理论设计"两文基于混沌设计的两个序列密码算法产生的乱数序列的前若干值对密钥的变化并不敏感,据此在已知混沌变换的条件下,可以利用已知明文采取先攻击高位密钥再攻击低位密钥的方法对这两个密码算法进行分割攻击.本文还提出了在正确密钥的分布已知条件下使平均计算复杂性达到最小的穷举攻击算法,并将它与分割攻击方法结合,提出了对上述两个密码算法的优化分割攻击方案,并分析了这两个攻击方案的计算复杂性和成功率. 相似文献
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Recently, a novel dynamical data encryption system based on synchronised chaotic systems was proposed for security communication. Based on the same synchronised chaotic systems, its dynamical cryptography is investigated. In this system, the ciphertext of each bit is mapped to one of two distinct chaotic dynamical equations. The ciphertext can be decrypted by its synchronised chaotic equation. This method can prevent intruders from recovering the information signals by statistical methods. To demonstrate its effectiveness, a 2 bit dynamical data cryptosystem based entirely on the Lorenz system is presented 相似文献
13.
提出了一个新的具有超多稳定性的三维连续自治混沌系统,该系统仅有2个非线性项.对系统的耗散性、平衡点的稳定性进行了定量分析,并利用分岔图、Lyapunov指数、彭加莱截面和吸引子相图分析了系统参数以及初值对其动力学行为的影响.在参数固定的情况下,分析初值变化的分岔图,得到了无限多种共存吸引子.通过采用模拟开关电子元件设计实现了该系统,同时运用Multisim软件仿真了该系统的混沌电路.结论证明电路仿真与数值仿真结果一致. 相似文献
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Based on the traditional Qi chaotic system,a novel unified chaotic system with the complex chaotic characteristics was constructed by adding the control parameters and modifying the nonlinear terms.Firstly,basic dynamical characteristics of chaotic system were analyzed,and phase portrait,time domain waveform diagram,Poincare mapping and power spectrum diagram were numerically simulated.Secondly,system parameters influence on chaotic system was discussed through Lyapunov exponent spectrum,bifurcation diagrams and chaotic signal amplitude.It was found that the unified chaotic system can generate the four new types of two-wing chaotic attractors with the multi-parameter invariable Lyapunov exponent spectrum characteristics.Meanwhile,there exist the functions of the global and local nonlinear amplitude modulation parameters.Thirdly,taking the first chaotic attractor of system as an example by introducing the two new types of nonlinear functions,the expansion of grid multi-wing attractor was realized.Finally,the hardware circuit of novel unified chaotic system was constructed.The four new types of chaotic attractors are observed experimentally,which is consistent with numerical simulation results and verified the feasibility of the proposed system. 相似文献
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嵌入式比特流混沌加密算法的研究与仿真 总被引:1,自引:1,他引:0
提出混沌与嵌入式比特流相结合的加密算法.首先,将原始图像进行二维小波变换后,转换成小波域上的小波系数,然后对小波系数进行嵌入零树小波编码.接着,使用分段线性混沌映射产生二进制混沌序列,对码流分组加密,该算法具有较高的安全性.仿真试验结果表明,该算法能够得到令人满意的结果. 相似文献
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简化Lorenz混沌系统的投影同步控制 总被引:1,自引:0,他引:1
针对最新研究的简化Lorenz混沌系统模型,分别采用比例投影同步和广义函数投影同步控制策略,研究了两个不同初值的简化Lorenz混沌系统的同步问题.基于罗斯-霍尔维兹准则和Lyapunov稳定性原理,推导了实现两混沌系统投影同步的同步定理,确定了实现投影同步的控制参数的取值范围:分析了控制参数对同步系统性能的影响规律.... 相似文献
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基于混沌的数码防伪系统研究与实现 总被引:1,自引:1,他引:0
设计并实现了一套基于混沌的数码防伪系统.基于混沌密码技术,分别提出一种生成防伪码和验证码的混沌密码加密算法,并采用"双标双码、双向验证"防伪工作机制,构建了一个能进行电话查询的混沌数码防伪系统,实现了防伪查询智能鉴别,系统测试表明该系统防伪效果好且方便实用,适合推广. 相似文献
20.
Cheng Juang Hwang T.M. Juang J. Wen-Wei Lin 《Quantum Electronics, IEEE Journal of》2000,36(3):300-304
A synchronization scheme using self-pulsating laser diodes in optical chaotic communication is proposed. Optical chaotic light can be obtained by injecting a sinusoidal electronic signal into a self-pulsating laser diode. To synchronize between two identical chaotic systems with different initial conditions, a drive and response system model is constructed according to Pecora and Carroll's theory. Synchronization can be achieved for optical simplex and duplex transmissions provided that the conditional Lyapunov exponents for the drive and response systems are all negative. This approach offers a key step toward realizing optical chaotic modulation and demodulation 相似文献