A color image encryption scheme based on a 2D coupled chaotic system and diagonal scrambling algorithm

A novel color image encryption scheme is developed to enhance the security of encryption without increasing the complexity. Firstly, the plain color image is decomposed into three grayscale plain images, which are converted into the frequency domain coefficient matrices(FDCM) with discrete cosine transform(DCT) operation. After that, a twodimensional(2D) coupled chaotic system is developed and used to generate one group of embedded matrices and another group of encryption matrices, respectively. The embedded matrices are integrated with the FDCM to fulfill the frequency domain encryption, and then the inverse DCT processing is implemented to recover the spatial domain signal. Eventually,under the function of the encryption matrices and the proposed diagonal scrambling algorithm, the final color ciphertext is obtained. The experimental results show that the proposed method can not only ensure efficient encryption but also satisfy various sizes of image encryption. Besides, it has better performance than other similar techniques in statistical feature analysis, such as key space, key sensitivity, anti-differential attack, information entropy, noise attack, etc.

New chaotical image encryption algorithm based on Fisher–Yatess scrambling and DNA coding

Based on the Fisher–Yatess scrambling and DNA coding technology, a chaotical image encryption method is proposed. First, the SHA-3 algorithm is used to calculate the hash value of the initial password, which is used as the initial value of the chaotic system. Second, the chaotic sequence and Fisher–Yatess scrambling are used to scramble the plaintext,and a sorting scrambling algorithm is used for secondary scrambling. Then, the chaotic sequence and DNA coding rules are used to change the plaintext pixel values, which makes the ciphertext more random and resistant to attacks, and thus ensures that the encrypted ciphertext is more secure. Finally, we add plaintext statistics for pixel-level diffusion to ensure plaintext sensitivity. The experimental results and security analysis show that the new algorithm has a good encryption effect and speed, and can also resist common attacks.

Double quantum images encryption scheme based on chaotic system

This paper explores a double quantum images representation(DNEQR)model that allows for simultaneous storage of two digital images in a quantum superposition state.Additionally,a new type of two-dimensional hyperchaotic system based on sine and logistic maps is investigated,offering a wider parameter space and better chaotic behavior compared to the sine and logistic maps.Based on the DNEQR model and the hyperchaotic system,a double quantum images encryption algorithm is proposed.Firstly,two classical plaintext images are transformed into quantum states using the DNEQR model.Then,the proposed hyperchaotic system is employed to iteratively generate pseudo-random sequences.These chaotic sequences are utilized to perform pixel value and position operations on the quantum image,resulting in changes to both pixel values and positions.Finally,the ciphertext image can be obtained by qubit-level diffusion using two XOR operations between the position-permutated image and the pseudo-random sequences.The corresponding quantum circuits are also given.Experimental results demonstrate that the proposed scheme ensures the security of the images during transmission,improves the encryption efficiency,and enhances anti-interference and anti-attack capabilities.

Remote sensing image encryption algorithm based on novel hyperchaos and an elliptic curve cryptosystem

Remote sensing images carry crucial ground information,often involving the spatial distribution and spatiotemporal changes of surface elements.To safeguard this sensitive data,image encryption technology is essential.In this paper,a novel Fibonacci sine exponential map is designed,the hyperchaotic performance of which is particularly suitable for image encryption algorithms.An encryption algorithm tailored for handling the multi-band attributes of remote sensing images is proposed.The algorithm combines a three-dimensional synchronized scrambled diffusion operation with chaos to efficiently encrypt multiple images.Moreover,the keys are processed using an elliptic curve cryptosystem,eliminating the need for an additional channel to transmit the keys,thus enhancing security.Experimental results and algorithm analysis demonstrate that the algorithm offers strong security and high efficiency,making it suitable for remote sensing image encryption tasks.

Period of Arnold transformation and its application in image scrambling

With the security problem of image information as the background, some more properties of the period of Arnold transformation of two-dimension were studied by means of introducing a integer sequence. Some new resuits are obtained. Two interesting conjectures on the period of Arnold transformation are given. When making digital images scrambling by Arnold transformation, it is important to know the period of the transformation for the image. As the application of the theory, a new method for computing the periods at last are proposed.

Multispectral image compression and encryption method based on tensor decomposition in wavelet domain

Multispectral image compression and encryption algorithms commonly suffer from issues such as low compression efficiency,lack of synchronization between the compression and encryption proces-ses,and degradation of intrinsic image structure.A novel approach is proposed to address these is-sues.Firstly,a chaotic sequence is generated using the Lorenz three-dimensional chaotic mapping to initiate the encryption process,which is XORed with each spectral band of the multispectral image to complete the initial encryption of the image.Then,a two-dimensional lifting 9/7 wavelet transform is applied to the processed image.Next,a key-sensitive Arnold scrambling technique is employed on the resulting low-frequency image.It effectively eliminates spatial redundancy in the multispectral image while enhancing the encryption process.To optimize the compression and encryption processes further,fast Tucker decomposition is applied to the wavelet sub-band tensor.It effectively removes both spectral redundancy and residual spatial redundancy in the multispectral image.Finally,the core tensor and pattern matrix obtained from the decomposition are subjected to entropy encoding,and real-time chaotic encryption is implemented during the encoding process,effectively integrating compression and encryption.The results show that the proposed algorithm is suitable for occasions with high requirements for compression and encryption,and it provides valuable insights for the de-velopment of compression and encryption in multispectral field.

Reversible Data Hiding in Classification-Scrambling Encrypted-Image Based on Iterative Recovery

To improve the security and quality of decrypted images,this work proposes a reversible data hiding in encrypted image based on iterative recovery.The encrypted image is firstly generated by the pixel classification scrambling and bit-wise exclusive-OR(XOR),which improves the security of encrypted images.And then,a pixel-typemark generation method based on block-compression is designed to reduce the extra burden of key management and transfer.At last,an iterative recovery strategy is proposed to optimize the marked decrypted image,which allows the original image to be obtained only using the encryption key.The proposed reversible data hiding scheme in encrypted image is not vulnerable to the ciphertext-only attack due to the fact that the XOR-encrypted pixels are scrambled in the corresponding encrypted image.Experimental results demonstrate that the decrypted images obtained by the proposed method are the same as the original ones,and the maximum embedding rate of proposed method is higher than the previously reported reversible data hiding methods in encrypted image.

ALCencryption:A Secure and Efficient Algorithm for Medical Image Encryption

With the rapid development of medical informatization and the popularization of digital imaging equipment,DICOM images contain the personal privacy of patients,and there are security risks in the process of storage and transmission,so it needs to be encrypted.In order to solve the security problem of medical images on mobile devices,a safe and efficient medical image encryption algorithm called ALCencryption is designed.The algorithm first analyzes the medical image and distinguishes the color image from the gray image.For gray images,the improved Arnold map is used to scramble them according to the optimal number of iterations,and then the diffusion is realized by the Logistic and Chebyshev map cross-diffusion algorithm.The color image is encrypted by cross-diffusion algorithm of double chaotic map.Security and efficiency analysis show that the ALCencryption algorithm has the characteristics of small neighboring pixels,large key space,strong key sensitivity,high safety and short encryption time.It is suitable for medical image encryption of mobile devices with high real-time requirements.

A New Digital Image Encryption Algorithm Based on Improved Logistic Mapping and Josephus Circle

Digital image encryption based on Joseph circle and Chaotic system has become a hot spot in the research of image encryption. An encryption algorithm based on improved Josephus loop and logistic mapping is proposed to scrambling blocks in this paper. At first, the original image is scrambled by using logistic mapping to obtain the encrypted image, and then the encrypted image is divided into many blocks. Finally, the position of the blocked image is scrambled by using the improved Josephus ring to get the encrypted image. According to the experiments, the information entropy of the encrypted image reaches 7.99 and the adjacent correlations in three directions are within ±0.1. The experimental results show that the proposed algorithm has advantages of large key space, high key sensitivity and can effectively resist the attacks of statistical analysis and gray value analysis. It has good encryption effect on digital image encryption.

A Novel Image Encryption Scheme Based on Reversible Cellular Automata

In this paper,a new scheme for image encryption is presented by reversible cellular automata.The presented scheme is applied in three individual steps.Firstly,the image is blocked and the pixels are substituted by a reversible cellular automaton.Then,image pixels are scrambled by an elementary cellular automata and finally the blocks are attached and pixels are substituted by an individual reversible cellular automaton.Due to reversibility of used cellular automata,decryption scheme can reversely be applied.The experimental results show that encrypted image is suitable visually and this scheme has satisfied quantitative performance.

基于行列异或的Arnold双置乱图像加密方法

针对目前加密图像单一以及加密算法安全性不高的问题,提出基于行列异或的Arnold双置乱图像加密方法。实施过程:首先根据Arnold变换公式对图像进行灰度空间置乱和位置空间置乱,然后进行行按位异或操作,其次,将上述结果再进行一次位置空间置乱,最后再进行列按位异或运算。该方法有效增强了传统Arnold双置乱的置乱效果,使图像得到充分扩散,最终得到密文图像。实验结果表明,本文方法能实现等长和不等长图像的置乱,改善了常规Arnold方法的置乱效果,有效降低了图像相邻像素间的相关性,保证了图像传输过程中的安全性和鲁棒性要求。

基于改进Logistic混沌和交叉混沌扩散的强鲁棒性图像加密

针对现有部分图像加密算法鲁棒性弱的问题,本文提出了一种基于改进Logistic混沌和交叉混沌序列扩散的强鲁棒性加密算法。首先,对Logistic一维混沌进行变换,构造出一种混沌序列分布更加随机的新混沌系统;然后,利用螺旋矩阵变换进行第一次置乱,利用明文的哈希值构造混沌的初始密钥,引入明文相关的两个数值val1和val2结合新混沌系统构造交叉混沌序列;接着对置乱后的序列进行交叉混沌的扩散。为克服螺旋矩阵变换部分像素未发生改变的问题,再进行一次交叉混沌置乱,形成置乱-扩散-置乱的加密框架。最后对本算法进行仿真模拟,其中本文密文图像的平均相关系数为–0.0027,更加趋近于0,大大的破坏了图像内部之间的相关性,达到图像加密的效果。像素变化率NPCR为99.61%,归一化强度UACI为33.36%,都分别接近于理想值99.60%和33.34%;密文图像的信息熵为7.9975,接近于理想值8,密钥的敏感性为10–17;能够在椒盐噪声和高斯噪声强度为0.2的情况下,仍然能够识别出解密图像。而且加密图像剪切1/2时,仍然能够恢复出明文图像;实验结果表明,本文算法具有较高的安全性,能够抵御选择明文攻击和穷举攻击,具有较强的抗噪声和抗剪切能力,对于图像传输过程中的安全性提供一定的保障,能够对于灰度图像达到安全稳定的加解密效果。

基于改进型3D_Henon混沌映射的彩色图像加密方法

为了解决现有混沌映射模型的混沌空间小及混沌能力弱的问题,首先通过耦合二维Henon混沌映射模型和Sine混沌映射模型,设计了一种新的三维混沌映射模型。其次,针对密钥重复使用会降低加密系统安全性的问题,使用Chebyshev映射,结合明文图像,设计出一种新的密钥生成方法。最后,通过本文设计的三维混沌映射模型以及密钥生成方法,提出了一种彩色图像加密方法,并对此方法进行了仿真实验,结果表明,该方法能够安全有效地进行图像加密,保护图像信息安全。

基于一个四维超混沌系统的图像加密算法

针对低维混沌系统复杂性低、应用在图像加密中效果差等问题,通过相图、分岔图、Lyapunov指数谱以及谱熵复杂度等方面探究了一个四维超混沌系统的动力学特性及其加密应用。仿真结果表明上述系统的混沌状态分布在较大的参数范围内并且具有较大的复杂度值,说明上述系统能够很好的应用于图像加密。为此设计了一种基于四维超混沌的图像加密方案。算法主要利用改进的Arnold变换将明文图像的像素点位置进行扰乱,并通过加取模运算对置乱后的图像进行扩散,得到加密图像。最后通过密钥空间、相邻像素间相关性、信息熵、直方图以及差分攻击等方面分析了算法的安全性能。实验结果表明,上述加密算法不仅能够有效地对图像进行加密而且具有较高的安全性能。

A new class of scrambling transformation and its application in the image information covering

This paper studies two kinds of nonlinear transformations, namely the higher-dimensional Arnold transformation and the higher-dimensional Fibonacci Q-transformation and discusses the scrambling action of the two transformations focusing on the phase space of the digital images. A sufficient and necessary condition that a matrix transformation of digital image has periodicity is given. The results show that the two transformations have potential application in the storage and transportation of image information for the purpose of information security.

基于Arnold-DWT-QR的脆弱性图像水印算法

在人物新闻图像中,人眼视觉更关注于人脸高频细节部分,为实现含水印的人物新闻图像受到任何微弱攻击情况下均不能完整提取出水印信息,且具有较好的不可感知性,提出了一种Arnold置乱结合离散小波变换(DWT)、正交三角分解法(QR)的脆弱性图像水印算法。首先将水印图像进行Arnold置乱加密,再提取载体图像B通道中人眼不敏感的低频细节部分进行QR分解,最后将Arnold置乱加密后的水印图像QR分解后嵌入在载体图像矩阵R中每一个元素,使较少的水印信息均嵌入在载体图像的每一个像素中。实验结果表明,该算法在未受攻击情况下平均峰值信噪比(PSNR)为51 dB,归一化相关系数(NC)为1.0,在任何强度的攻击下均无法提取完整水印图像,具有较好的人物新闻图像认证能力。

基于Piecewise映射的安全密文域可逆信息隐藏算法

密文域可逆信息隐藏(RDH-ED)中常采用对称加密,但仅采用流密码异或(XOR)、置乱或两者结合的方法,在现有条件下难以抵抗唯密文攻击、选择明文攻击或已知明文攻击(KPA)。为了提高RDH-ED的安全性,提出一种基于Piecewise混沌映射的安全RDH-ED加密算法。首先对明文图像进行分块并按比特异或,随后利用Piecewise混沌映射转换密钥来对异或后的图像进行块内位平面置乱,最后对图像进行块间置乱加密。实验结果表明:所提算法在能够达到像素值均匀分布、视觉上不可感知的基础上,密钥空间相比单一加密方式增大至2^(8N_(p))×N_(p)!×8!^(N_(p)),并能够抵抗现有的各类攻击方法;最近的KPA测试下破解率为0.0067%,在保留适当嵌入量的同时增强了图像的安全性。同时,该算法通过Piecewise映射使得密钥通信量不变,并能够保证完全可逆地恢复原始图像。

基于视觉关联的数字图像置乱加密方法

针对现有数字图像加密方法存在的加密效果差、加密时间长、抗攻击能力弱等问题,提出基于视觉关联的数字图像置乱加密方法。应用小波变换原理提取数字图像视觉关联信息—纹理特征信息,以此为基础,结合内部与外部密钥在Henon与Logistic映射算法的共同应用下,生成数字图像密钥,融合分层旋转置乱方式与循环移动置乱方式制定数字图像置乱规则。基于密钥与置乱规则编制数字图像置乱加密与解密程序,执行程序即可实现数字图像的置乱加密与解密。实验结果显示:提出方法应用后加密图像不动点比最小值为4.12%,数字图像加密平均时间最小值为0.89s/幅,置乱加密数字图像密钥破解比例为4%。

基于耦合的Henon和Sine映射及彩色图像加密

针对现有混沌映射模型的混沌空间小及混沌能力弱的问题,通过耦合二维Henon混沌映射模型和Sine混沌映射模型,设计一种新的二维混沌映射模型,通过耦合Sine混沌映射模型和Logistic混沌映射模型,设计一种新的一维混沌映射模型。针对使用单一置乱方法进行图像加密时安全性能不高的问题,通过使用Lorenz映射设计一种随机选择置乱算法的方法。使用设计的两种混沌映射及置乱选择方法,提出一种彩色图像加密方案。仿真实验结果表明:所提方法具有较大的置乱范围、较高的安全性和良好的图像加密效果,对常见的攻击有较强的抵抗力,且易于实现。

一类多涡卷Chua系统及其在图像加密中的应用

为使混沌序列表现出更复杂的特性,在典型的Chua系统上引入了分段线性函数,使所得的系统产生可控数量的多涡卷吸引子。对该系统进行动力学分析,分析结果表明,该系统混沌特性分布广泛,具有丰富的动力学行为。在此基础上,提出了一种基于Zigzag置乱和DNA编码的加密算法,并从多个方面对该算法的安全性进行了分析。仿真结果验证了该方法不仅能对图像进行有效加密,而且能有效抵抗各种常见的攻击,为图像加密提供了理论依据。