A novel block encryption scheme based on chaos and an S-box for wireless sensor networks

The wireless sensor network （WSN） has been widely used in various fields, but it still remains in the preliminary discovery and research phase with a lack of various related mature technologies. Traditional encryption schemes are not suitable for wireless sensor networks due to intrinsic features of the nodes such as low energy, limited computation capability, and lack of storage resources. In this paper, we present a novel block encryption scheme based on the integer discretization of a chaotic map, the Feistel network structure, and an S-box. The novel scheme is fast, secure, has low resource consumption and is suitable for wireless sensor network node encryption schemes. The experimental tests are carried out with detailed analysis, showing that the novel block algorithm has a large key space, very good diffusion and disruptive performances, a strict avalanche effect, excellent statistical balance, and fast encryption speed. These features enable the encryption scheme to pass the SP800-22 test. Meanwhile, the analysis and the testing of speed, time, and storage space on the simulator platform show that this new encryption scheme is well able to hide data information in wireless sensor networks.

Image encryption technique based on new two-dimensional fractional-order discrete chaotic map and Menezes–Vanstone elliptic curve cryptosystem

We propose a new fractional two-dimensional triangle function combination discrete chaotic map(2D-TFCDM)with the discrete fractional difference.Moreover,the chaos behaviors of the proposed map are observed and the bifurcation diagrams,the largest Lyapunov exponent plot,and the phase portraits are derived,respectively.Finally,with the secret keys generated by Menezes-Vanstone elliptic curve cryptosystem,we apply the discrete fractional map into color image encryption.After that,the image encryption algorithm is analyzed in four aspects and the result indicates that the proposed algorithm is more superior than the other algorithms.

An improved image encryption algorithm based on chaotic maps

Recently, two chaotic image encryption schemes have been proposed, in which shuffling the positions and changing the grey values of image pixels are combined. This paper provides the chosen plaintext attack to recover the corresponding plaintext of a given ciphertext. Furthermore, it points out that the two schemes are not sufficiently sensitive to small changes of the plaintext. Based on the given analysis, it proposes an improved algorithm which includes two rounds of substitution and one round of permutation to strengthen the overall performance.

High Security Nested PWLCM Chaotic Map Bit-Level Permutation Based Image Encryption

Chaotic systems produce pseudo-random sequences with good randomness;therefore, these systems are suitable to efficient image encryption. In this paper, a low complexity image encryption based on Nested Piece Wise Linear Chaotic Map (NPWLCM) is proposed. Bit planes of the grey or color levels are shuffled to increase the encryption complexity. A security analysis of the proposed system is performed and presented. The proposed method combine pixel shuffling, bit shuffling, and diffusion, which is highly disorder the original image. The initial values and the chaos control parameters of NPWLCM maps are derived from external secret key. The cipher image generated by this method is the same size as the original image and is suitable for practical use in the secure transmission of confidential information over the Internet. The experimental results of the proposed method show advantages of low complexity, and high-level security.

A New Study in Encryption Based on Fractional Order Chaotic System

In this paper, we introduce a novel approach to achieve the data encryption. The fractional order Lorenz chaotic system is used to generate the chaotic sequence and the characteristics of the chaotic sequence are studied. Some examples concerned with text and image encryption are also presented in the paper, which show exciting results by the approach we introduced.

Rucklidge-based memristive chaotic system:Dynamic analysis and image encryption

A new four-dimensional(4D)memristive chaotic system is obtained by introducing a memristor into the Rucklidge chaotic system,and a detailed dynamic analysis of the system is performed.The sensitivity of the system to parameters allows it obtains 16 different attractors by changing only one parameter.The various transient behaviors and excellent spectral entropy and C0 complexity values of the system can also reflect the high complexity of the system.A circuit is designed and verified the feasibility of the system from the physical level.Finally,the system is applied to image encryption,and the security of the encryption system is analyzed from multiple aspects,providing a reference for the application of such memristive chaotic systems.

A new color image encryption scheme based on chaos synchronization of time-delay Lorenz system

In this paper, a new image encryption scheme is presented based on time-delay chaos synchronization. Compared with existing methods, a new method is pro- posed and a lot of coupled items can be taken as zero items to simplify the whole system. A simple linear controller is introduced to realize time-delay chaos synchronization and image encryption. The positions of the image pixels are firstly shuffled and then be hidden in the cartier image. The address codes of the chaotic sequences are adopted to avoid the disturbances induced by the initial value and computer accuracy error. Simulation results for color image are provided to illustrate the effectiveness of the proposed method. It can be seen clearly that the system can converge quickly and the image can be encrypted rapidly.

A Cross-Plane Color Image Encryption Algorithm Based on 1D-SLM

With the rapid development of 5G technology,it has become fast and easy for people to transmit information on the Internet.Digital images can express information more intuitively,so transmitting information through images has excellent applications.This paper uses a new chaotic system called 1D-Sin-Logistic-Map(1D-SLM).1D-SLM has two control parameters,which can provide larger parameter space,and the parameter space in the chaotic state is continuous.Through Lyapunov exponent analysis(LE),bifurcation diagrams analysis,spectral entropy analysis(SE),and 0-1 test,it is verified that 1D-SLM has complex dynamic behavior and is very suitable for cryptography.Compared with other 1D chaotic systems,the 1D-SLM has a larger Lyapunov exponent(LE)and spectral entropy(SE).For color image encryption algorithms,only relying on chaotic mapping is not enough to ensure security.So combined with 1D-SLM,we design a color image encryption algorithm,which is implemented by plane expansion,which reduces the correlation between the three channels of color images.The experimental results show that the proposed cross-plane color image encryption algorithm is safe and resistant to common attack methods.

Chaos-Based Encryption Algorithm for Compressed Video

Encryption for compressed video streams has attracted increasing attention with the exponential growth of digital multimedia delivery and consumption. However, most algorithms proposed in the literature do not effectively address the peculiarities of security and performance requirements. This paper presents a chaos-based encryption algorithm called the chaotic selective encryption of compressed video (CSECV) which exploits the characteristics of the compressed video. The encryption has three separate layers that can be selected according to the security needs of the application and the processing capability of the client computer. The chaotic pseudo-random sequence generator used to generate the key-sequence to randomize the important fields in the compressed video stream has its parameters encrypted by an asymmetric cipher and placed into the stream. The resulting stream is still a valid video stream. CSECV has significant advantages over existing algorithms for security, decryption speed, implementation flexibility, and error preservation.

A medical image encryption algorithm based on synchronization of time-delay chaotic system

This paper presents a new synchronization method of the time-delay chaotic system and its application in medical image encryption. Compared with the existing techniques, the error system is greatly simplified because many coupled items can be considered zero items. An improved image encryption scheme based on a dynamic block is proposed. This scheme divides the image into dynamic blocks, and the number of blocks is determined by a previous block cipher. Numerical simulations are provided to illustrate the effectiveness of the proposed method.

Composite Chaotic Pseudo-Random Sequence Encryption Algorithm for Compressed Video

Stream cryptosystems, which implement encryption by selecting parts of the block data and header information of the compressed video stream, achieve good real-time encryption with high flexibility. Chaotic random number generator-based approaches, for example, logistics maps, are comparatively promising approachs, but are vulnerable to attacks by nonlinear dynamic forecasting. A composite chaotic cryptography scheme was developed to encrypt the compressed video with the logistics map with a Z(2311) field linear congruential algorithm to strengthen the security of the mono-chaotic cryptography. The scheme maintained real-time performance and flexibility of the chaotic sequence cryptography. The scheme also in-tegrated asymmetrical public-key cryptography and encryption and identity authentification of control pa-rameters at the initialization phase. Encryption is performed in a layered scheme based on the importance of the data in a compressed video stream. The composite chaotic cryptography scheme has the advantage that the value and updating frequency of the control parameters can be changed online to satisfy the net-work requirements and the processor capability, as well as the security requirements. Cryptanalysis shows that the scheme guarantees robust security,provides good real-time performance,and has flexible im-plementation. Statistical evaluations and tests verify that the scheme is effective.

New Chaotic Image Encryption Algorithm Based on Cross-Mapping

Chaotic cryptography has been applied to image encryption;however,only the traditional low-dimensional chaotic systems has been widely analyzed or deciphered,which does not show satisfied security and efficiency.To solve this problem,a new algorithm based on cross-chaos map has been created in this article.The image pixels are scrambled under control of high-dimensional chaotic sequence,which is generated by cross chaotic map.The image pixels are substituted by ciphertext feedback algorithm.It can relate encryption required parameters with plaintext and can make a plaintext byte affect more ciphertext bytes.Proved by theoretical analysis and experimental results,the algorithm has higher complex degree and has passed SP800-22 pseudo-random number standard tests,and it has high encryption speed,high security,etc.It can be widely applied in the field of image encryption.

A novel image block cryptosystem based on a spatiotemporal chaotic system and a chaotic neural network

In this paper, we propose a novel block cryptographic scheme based on a spatiotemporal chaotic system and a chaotic neural network （CNN）. The employed CNN comprises a 4-neuron layer called a chaotic neuron layer （CNL）, where the spatiotemporal chaotic system participates in generating its weight matrix and other parameters. The spatiotemporal chaotic system used in our scheme is the typical coupled map lattice （CML）, which can be easily implemented in parallel by hard- ware. A 160-bit-long binary sequence is used to generate the initial conditions of the CML. The decryption process is symmetric relative to the encryption process. Theoretical analysis and experimental results prove that the block cryptosys- tem is secure and practical, and suitable for image encryption.

A Novel Internet of Medical Thing Cryptosystem Based on Jigsaw Transformation and Ikeda Chaotic Map

Image encryption has attracted much interest as a robust security solution for preventing unauthorized access to critical image data.Medical picture encryption is a crucial step in many cloud-based and healthcare applications.In this study,a strong cryptosystem based on a 2D chaotic map and Jigsaw transformation is presented for the encryption of medical photos in private Internet of Medical Things(IoMT)and cloud storage.A disorganized three-dimensional map is the foundation of the proposed cipher.The dispersion of pixel values and the permutation of their places in this map are accomplished using a nonlinear encoding process.The suggested cryptosystem enhances the security of the delivered medical images by performing many operations.To validate the efficiency of the recommended cryptosystem,various medical image kinds are used,each with its unique characteristics.Several measures are used to evaluate the proposed cryptosystem,which all support its robust security.The simulation results confirm the supplied cryptosystem’s secrecy.Furthermore,it provides strong robustness and suggested protection standards for cloud service applications,healthcare,and IoMT.It is seen that the proposed 3D chaotic cryptosystem obtains an average entropy of 7.9998,which is near its most excellent value of 8,and a typical NPCR value of 99.62%,which is also near its extreme value of 99.60%.Moreover,the recommended cryptosystem outperforms conventional security systems across the test assessment criteria.

A Speech Cryptosystem Using the New Chaotic System with a Capsule-Shaped Equilibrium Curve

In recent years,there are numerous studies on chaotic systems with special equilibrium curves having various shapes such as circle,butterfly,heart and apple.This paper describes a new 3-D chaotic dynamical system with a capsule-shaped equilibrium curve.The proposed chaotic system has two quadratic,two cubic and two quartic nonlinear terms.It is noted that the proposed chaotic system has a hidden attractor since it has an infinite number of equilibrium points.It is also established that the proposed chaotic system exhibits multi-stability with two coexisting chaotic attractors for the same parameter values but differential initial states.A detailed bifurcation analysis with respect to variations in the system parameters is portrayed for the new chaotic system with capsule equilibrium curve.We have shown MATLAB plots to illustrate the capsule equilibrium curve,phase orbits of the new chaotic system,bifurcation diagrams and multi-stability.As an engineering application,we have proposed a speech cryptosystem with a numerical algorithm,which is based on our novel 3-D chaotic system with a capsule-shaped equilibrium curve.The proposed speech cryptosystem follows its security evolution and implementation on Field Programmable Gate Array(FPGA)platform.Experimental results show that the proposed encryption system utilizes 33%of the FPGA,while the maximum clock frequency is 178.28 MHz.

Discrete memristive neuron model and its interspike interval-encoded application in image encryption

Bursting is a diverse and common phenomenon in neuronal activation patterns and it indicates that fast action voltage spiking periods are followed by resting periods.The interspike interval(ISI)is the time between successive action voltage spikes of neuron and it is a key indicator used to characterize the bursting.Recently,a three-dimensional memristive Hindmarsh-Rose(mHR)neuron model was constructed to generate hidden chaotic bursting.However,the properties of the discrete mHR neuron model have not been investigated,yet.In this article,we first construct a discrete mHR neuron model and then acquire different hidden chaotic bursting sequences under four typical sets of parameters.To make these sequences more suitable for the application,we further encode these hidden chaotic sequences using their ISIs and the performance comparative results show that the ISI-encoded chaotic sequences have much more complex chaos properties than the original sequences.In addition,we apply these ISI-encoded chaotic sequences to the application of image encryption.The image encryption scheme has a symmetric key structure and contains plain-text permutation and bidirectional diffusion processes.Experimental results and security analyses prove that it has excellent robustness against various possible attacks.

抵抗泄露攻击的无线传感器网络分组加密算法

混沌作为一种复杂的动力学系统,和密码学中的很多特性具有相似性。混沌内在的类随机特性对应于伪随机序列,混沌对初始条件和控制参数的极端敏感性对应于传统密码的混乱扩散特性。结合这些特性,提出抵抗泄露攻击的无线传感器网络分组加密算法。基于混沌S盒方法完成分组初加密,生成子密钥,构建抵抗泄漏攻击的CCA安全密钥以优化无线传感器网络分组加密,通过算法输入的方式优化密钥的加密算法,定义封装密钥空间。利用CPA密钥的安全性保证加密密钥输出,满足无线传感器网络抵抗泄漏攻击的要求。仿真结果表明:所提方法的信息熵值始终高于7.99,执行时间始终低于12.1 ms,所需存储空间始终低于126 bytes,保密性能和保密效果更好,具有较高的实际应用价值。

一种改进类提升方案的双彩色图像加密系统

如今图像信息安全面临着严峻的考验,而图像加密技术是应对这一考验最有效的手段之一。由于提升方案在图像加密中具有更快的加解密速度和良好的安全性,所以越来越多基于提升方案的加密系统被提出。文中提出了一种改进类提升方案的双彩色图像加密系统。首先,将彩色图像分成3个通道:R通道、G通道和B通道。然后,将每个图像分别当成魔方的6个面,使用随机序列控制魔方的旋转,从而达到置乱和加密图像的效果。其次,为了使整个系统具有更高的安全性,将改进类提升方案的更新和预测函数由类感知器网络(Perceptron-Like Network,PLN)代替。与原先运算简单的线性函数相比,PLN具有更加复杂的计算和不可预测性。通过所提结构得到的加密图像具有更高的加密质量,因此可以更好地将图像信息扩散到各个像素之间。大量的实验结果表明,该系统可以很好地抵抗各种攻击,具有很高的安全性;并且本系统对普通图像和密钥都具有很强的敏感性,因此可以应用于实际的图像加密。

一类混沌系统的滑模控制及其在安全通信中应用

混沌序列表现出来的特征与密码学非常相似,非常适合于安全通信中的信号加密。这种加密方案都是基于混沌同步控制的技术。现有的自适应滑模同步控制虽然能达到混沌同步控制的效果,但是造成了系统结构复杂化,同时还存在稳定性差等问题。为了简化系统的结构,同时确保系统的稳定性,基于主从控制技术研究了一类混沌系统的滑模同步控制并在安全通信中开展应用。首先,通过构建Lyapunov函数从理论上证实了系统同步稳定性的条件。其次,根据驱动系统只有一个控制器的结构特点,选择滑模控制设置合适的参数实现了Loren混沌系统的同步控制。再次,结合混沌掩盖技术将该方案应用到安全通信中。最后进行了数值仿真,结果表明系统在2.2 s左右实现了同步,并且混沌加密的信号经过同步信号解密后与原信号完全一致,数值仿真结果验证了方案的正确性。

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。