共查询到19条相似文献，搜索用时 171 毫秒
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为了研究混沌系统在数字图像加密环节已经取得的成功经验和在实际应用中遇到的问题,将混沌系统应用到图像置乱归纳出主要的设计理念和设计思路,对混沌的图像加密发展进行简要综述,分析讨论图像置乱的各种方法和基础理论知识和设计规程,同时提出了以前的置乱方法和相关加密算法存在的不足。介绍了混沌作用于加密系统的一般思路和应用混沌进行加密时应注意的几个问题,依据自己的研究针对现在存在的问题提出新的混沌图像加密置乱的方法和技巧,对混沌提出了灰度替换和像素置乱算法的评估标准等新见解,对混沌应用图像加密时应避免地问题和混沌系统与图像加密系统融合的基本思路作了简要的介绍,从新的视角和高度分析评估像素值置乱计算与灰度值替代,对以前的评估标准进行改进,最后对混沌图像加密系统的发展前景进行展望。 相似文献
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混沌同步理论视频加密技术研究 总被引：1，自引：0，他引：1
加密技术一直是国内外研究热点问题.本文利用混沌同步理论对视频图像进行加密处理,采用混沌理论中的Logistic映射序列密码加密系统进行加密.实验结果说明了采用该方法能够有效地对视频图像进行加密. 相似文献
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量子通信中的密钥设计是整个量子通信系统安全性的重要保障,传统的密钥设计方法采用固定密钥,无法实现变密钥加密,所以密钥和通信内容被破解的概率很高。提出一种基于色散评价的量子通信变密钥混沌加密实现方法,每次通信时,从混沌学的角度提取所有待通信数据的深层次特征,然后形成本次通信的加密和解密密钥,随通信内容的不同,系统密钥实时变化,在接收端,通过密钥和通信内容的混沌匹配来实现解密,并采用色散特性对加密效果进行评价。通过一组通信内容进行混沌加密性能测试,结果显示,基于色散特性衡量下的混沌加密特性安全性较传统方法大大提高,加密文本被破解的概率是0.0011%。 相似文献
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高维混沌一般为复杂的微分或者是差分方程组,求解的复杂度和计算量都很大,会降低加密算法的速度,然而单一的低维混沌系统无法满足安全性的要求,因此运用低维的混沌系统进行复合,得到复合的混沌加密系统,既能满足安全性的要求,加密速度也够快。提出一种基于有限域chebyshev和分段线性混沌映射PWLCM的公钥加密方案。 相似文献
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公安网络系统单纯采用一种加密技术无法确保混合公安网络系统的安全,弊端明显。分析了对称加密和非对称加密技术,提出一种混合公安网络中融合加密技术,先采用二者结合的混合加密方法,对混合公安网络进行初始加密,再通过基于超混沌映射的数据融合加密算法,对混合公安网络进行再次加密,采用Chen超混沌系统形成四条混沌序列,对这四条混沌序列进行取小数部分、矩阵相乘及取索引值等变形处理,分别利用变形后的混沌序列对原始数据和密钥进行位置置乱处理,用交换位平面和按位取反处理扰乱数据值,通过加运算获取加密数据。实验结果说明,所提融合加密技术具有较高的加密效率和质量。 相似文献
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基于USB智能卡的文件加密方法 总被引：2，自引：0，他引：2
本文详细介绍了一种基于USB智能卡的文件加密方法。系统采用软硬件结合的原则,由软件进行文件加密,硬件负责密钥的管理和会话密钥的加密。利用USB智能卡管理密钥,实现了双因子认证方式;加密时采用公钥算法RSA结合传统加密的杂合算法。系统实现了高安全、高效率、方便易用的文件加密方法;同时,基于USB智能卡的特点,系统可扩充性强。 相似文献
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DES算法已被应用于许多需要安全加密的场合(如信用卡持卡人的PIN加密传输、IC卡与POS间的双向认证、金融数据包校验等),深入地分析了DES算法的思想、加密过程及应用,并指出了DES算法的优势和不足。 相似文献
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During the recent years several chaotic image encryption algorithms have been proposed, but most of them encountered some drawbacks such as small key space, low speed, lack of robustness and low security. In this paper, we have proposed an image algorithm based on the combination of a one-dimensional polynomial chaotic map and a piecewise nonlinear chaotic map. Theoretical analysis and computer simulations, both confirm that the new algorithm possesses high security, robust fast encryption speed for practical image encryption and solves the problem of small key space. 相似文献
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《Journal of The Franklin Institute》2019,356(18):11638-11667
This paper proposes a new image encryption method based on matrix semi-tensor product theory. Using Hyperchaotic Lorenz system to generate chaotic sequences, and then using this chaotic sequence to generate two fixed scrambling matrices. The plain image is scrambled by chaotic positioning sort scrambled method. Analogous to a chemical reaction, the plain image scrambled image is one of the reactant, then add a matrix which is related to the plain image information and extracted from the chaotic sequence (this matrix can be differ in size from the plain image matrix, different matrices can be intercepted and generated according to different plain image). This matrix is scrambled as another reactant, Apply the method of semi-tensor product to carry on the reaction (diffusion), finally get the product (encryption image). This method breaks the shackles of the traditional matrix operation and makes the reaction matrix have more forms. Compared with other experimental results, the proposed algorithm is more secure and available. 相似文献
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提出了一种基于逐段线性混沌系统的图像加密算法。通过对外部密钥的映射,分别产生系统的初值和参数值,根据图像大小经16个逐段线性映射迭代出足够的密钥流,并引入密文反馈机制,对图像像素值逐个进行多轮异或加密。实验表明,这种加密算法使密文对明文和密钥都充分敏感,加密图像像素值具有类随机均匀分布特性。而且算法具有密钥空间大、加密速度快的优越性。 相似文献
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针对基于传统的密码算法保密电话数据加密存在的缺陷,提出一种基于成对载波和混沌加密技术的保密电话解决方案。该方案用成对载波和回波抵消的体制保证语音信号的安全,用密码的方法保证整个数字传输通信系统的安全性,因此,电话系统保密性更高,实用性更强。 相似文献
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In this paper, a new technique is introduced for chaos secure data communication. In this approach, in addition to the usually used techniques for data encryption, the concept of carrier encryption is introduced to increase the security level of the secure communication scheme. To fulfill this objective, at the transmitting end, two chaotic oscillators are coupled, and a set of inequality time dependent constraints with time dependent bounds is imposed on the generated chaotic signals. Moreover, to increase system complexity and its security level, the imposed set of constraints and their bounds are allowed to be changeable from one time period to another during the transmission process. As a result, the patterns of the generated chaotic signals are completely changed and the chaotic oscillator is completely encrypted. At the receiving end, the newly developed Constrained Smoothed Regularized Least Square (CSRLS) observer is used to synchronize the received constrained chaotic signals and hence retrieve the transmitted data. Using such an approach, the quality of the received information, measured by the Bit Error Rate (BER), is highly improved due to the superior performance of the developed CSRLS observer. The stability of the observer is analyzed, and simulation results are presented to show the efficiency and effectiveness of the proposed secure communication scheme. 相似文献
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《Journal of The Franklin Institute》2021,358(16):8109-8137
In this work, a model-free adaptive sliding mode control (ASMC) methodology is proposed for synchronization of chaotic fractional-order systems (FOSs) with input saturation. Based on the frequency distributed model and the non-integer version of the Lyapunov stability theorem, a model-free ASMC method is designed to overcome the chaotic behavior of the FOSs. The control inputs are free from the nonlinear-linear dynamical terms of the system because of utilizing the boundedness feature of the states of chaotic FOSs. Moreover, a new medical image encryption scheme is tentatively proposed according to our synchronization method, and its effectiveness is verified by numerical simulations. Furthermore, the performance and security analyses are given to confirm the superiority of the proposed encryption scheme, including statistical analysis, key space analysis, differential attack analysis, and time performance analysis. 相似文献