Image encryption using novel chaotic map and cellular automata dynamics

Image encryption based on chaotic maps is an important method for ensuring the secure communication of digital multimedia on the Internet. To improve the encryption performance and security of image encryption systems, a new image encryption algorithm is proposed that employs a compound chaotic map and random cyclic shift. First, a new hybrid chaotic system is designed by coupling logistic, ICMIC, Tent, and Chebyshev (HLITC) maps. Comparison tests with previous chaotic maps in terms of chaotic trajectory, Lyapunov exponent, and approximate entropy illustrate that the new hybrid chaotic map has better chaotic performance. Then, the proposed HLITC chaotic system and spiral transformation are used to develop a new chaotic image encryption scheme using the double permutation strategy. The new HLITC chaotic system is used to generate key sequences used in the image scrambling and diffusion stages. The spiral transformation controlled by the chaotic sequence is used to scramble the pixels of the plaintext image, while the XOR operation based on a chaotic map is used for pixel diffusion. Extensive experiments on statistical analysis, key sensitivity, and key space analysis were conducted. Experimental results show that the proposed encryption scheme has good robustness against brute-force attacks, statistical attacks, and differential attacks and is more effective than many existing chaotic image encryption algorithms.

In the last decade, the communication of images through the internet has increased. Due to the growing demands for data transfer through images, protection of data and safe communication is very important. For this purpose, many encryption techniques have been designed and developed. New and secured encryption schemes based on chaos theory have introduced methods for secure as well as fast communication. A modified image encryption process is proposed in this work with chaotic maps and orthogonal matrix in Hill cipher. Image encryption involves three phases. In the first phase, a chaotic Henon map is used for permuting the digital image. In the second phase, a Hill cipher is used whose encryption key is generated by an orthogonal matrix which further is produced from the equation of the plane. In the third phase, a sequence is generated by a chaotic tent map which is later XORed. Chaotic maps play an important role in the encryption process. To deal with the issues of fast and highly secured image processing, the prominent properties of non-periodical movement and non-convergence of chaotic theory play an important role. The proposed scheme is resistant to different attacks on the cipher image. Different tests have been applied to evaluate the proposed technique. The results of the tests such as key space analysis, key sensitivity analysis, and information entropy, histogram correlation of the adjacent pixels, number of pixel change rate (NPCR), peak signal to noise ratio (PSNR), and unified average changing intensity (UCAI) showed that our proposed scheme is an efficient encryption technique. The proposed approach is also compared with some state-of-the-art image encryption techniques. In the view of statistical analysis, we claim that our proposed encryption algorithm is secured.

In today’s world of critical global connectivity, satellite communication plays a vital role for businesses, governments, and individuals. Key applications, including climate change monitoring, military surveillance, and real-time event broadcasting, heavily rely on transmitting image data rather than text. As a result, ensuring the secure transmission of images through efficient and robust encryption techniques has become a focal point of interest for both academia and industry. Image encryption is essential for securing sensitive visual data, protecting privacy, and making certain that only authorized users are able to access the required content. It prevents unauthorized access, tampering, and misuse of images, which is crucial for confidential and secure communications. The work in this paper develops a satellite image encryption scheme that employs a novel 1D Cosine Sinusoidal Chaotic (1DCSC) map, and two earlier proposed Sine-Tangent Chaotic (STC) and Improved Cosine Fractional Chaotic (ICFCM) maps, in conjunction with Deoxyribonucleic Acid (DNA) operations. The proposed scheme encrypts a given input image in four steps. In the initial step, 384-bit shared key and a 128-bit initial vector are used to create three different keys. In step two, three different chaotic sequences are produced using these keys and 1DCSC, STC, and ICFCM maps. These chaotic sequences chosen randomly to encrypt red, blue or green components of the given input image. In step three, these three chaotic sequences and the three components of the input image are DNA encoded. In the final step, DNA XOR based diffusion operation is applied between these DNA-encoded color image components and DNA encoded chaotic sequences to create green, red, and blue components of the cipher image. The proposed scheme obtains entropy value 7.9997, Unified Average Changing Intensity (UACI) value 33.32, and Number of Pixels Change Rate (NPCR) value 99.67%.

The main purpose of the proposed image encryption (IE) method is to enhance various security characteristics to protect sensitive images on the internet. In the literature, chaotic maps are preferred for image encryption because of their high randomness and sensitivity to initial parameter values. Therefore, metaheuristic algorithms have been utilized to fine-tune the parameters. In this research, we have employed the metaheuristic Lyrebird optimization (LO) algorithm to fine-tune the chaotic map parameters. The LO algorithm is chosen over other algorithms due to its better exploration and exploitation rate to search for the best solution. The LO algorithm searches for the best parameter value based on the objective function. This research involves the formulation of a multi-objective function that incorporates numerous security parameters, namely, entropy and correlation coefficient (CC), to improve the security attributes of the IE model. The proposed IE model has two steps. In the first step, a random key is generated to transform the pixels of the secret image, whereas in the second step, the image pixels are shuffled based on the shuffling index values to reduce the correlation among the neighboring pixels. In both steps, we have used the chaotic logistic map. The proposed IE is evaluated against statistical and differential attacks on the standard dataset by considering the various images and their different resolutions. The uniform distribution of the histogram of the encrypted images is validated using the chi-square test. Besides that, entropy analysis shows that the average entropy value is 7.9973, 7.9993, and 7.9998 for 256x256, 512x512, and 1024x1024 image resolutions. The average CC and SSIM are near zero value. The average NPCR value (>0.9969) is near the 1 value. Finally, the comparative analysis based on entropy, CC, and NPCR parameters shows that the proposed IE model outperforms the existing models.

A novel image encryption scheme using both pixel level and bit level permutation with chaotic map

Exponentially increasing multimedia data over the internet raises concerns over its security. In the current work, we present a new technique for encrypting digital images based upon the pixel shuffling combined with changing pixel values using 128-bit secret key using henon chaotic map. Chaotic maps are characterized by their high sensitivity towards the initial parameters, which makes it a natural choice for developing a dynamic permutation matrix or as it is mostly called, permutation map. So we used chaotic Henon map in order to dynamically generate the permutation matrix. The initial parameters of the chaotic map and the secret key for changing the pixel values are derived from an external secret key. Horizontal and vertical permutations are used to perform pixel shuffling. Shuffling is used to destroy the correlation among the neighbour or adjacent image pixels, also it helps in increasing diffusion in the image. The proposed scheme is tested against a series of tests to measure its performance. Results of such tests indicate that the proposed algorithm is highly sensitive towards the encryption key and showed high resistance against various brute-force or statistical attacks.

Image encryption with compound chaotic sequence cipher shifting dynamically

Chaos and compressive sensing based novel image encryption scheme

The encrypted data play a valuable role in image processing applications especially during transmission. For fast and secure image encryption, chaotic maps are applied to improve image encryption efficiency as it is highly sensitive to system parameters initial values and has a large key space. This paper introduced a secure algorithm for images encryption and decryption by using chaotic Baker Map in the discrete Fourier transform (DFT). The proposed method employs baker map in the frequency domain to act on the transformed image coefficients which achieves high encryption efficiency. Simulation for statistical analysis using MATLAB are designed and tested. The achieved results demonstrated the superiority of the proposed approach with respect to encryption quality, statistical, information entropy, maximum deviation, and irregular deviation, differential, and noise immunity tests.

The current information age demands enormous opportunities, where, the sensitive data and information is being exchanged, analyzed and made use of. It has led to several concerns and challenges, mainly in the areas of information privacy, authentication and integrity. This concern, attracted cryptographers to device more effective methodologies and algorithms to ensure better protection to sensitive information. In this context, the application of chaotic based systems is considered to design a pseudorandom sequence generator, which is used as a key stream generator in the additive Stream Cipher system. Chaotic map is a mathematic function that generates highly nonlinear and random real sequence which is very sensitive to initial conditions. In this view, this work focusses on the study of Logistic map, considered from a bunch of various Chaotic functions available [1], [2]. Chaotic real sequence is binarized using a new binarization algorithm using Linear Feedback Shift Register (LFSR), which is designed in such a way that the randomness of Chaotic real sequence is not affected as far as possible. Using Logistic map, about 50 sequences are generated each of length ≥ 106. To ensure the randomness of binary sequences, NIST(National Institute of Standards and Technology) test is used. It is observed that, all the sequences have strictly passed most of the NIST tests with an average passing proportion ≥ 0.87. These sequences are used as key sequences in image encryption and decryption. It is interesting to observe that, encrypted image does not contain any residual information. This result is cross verified by plotting the Histogram, computing the Correlation coefficient and Entropy of the output images. It is observed that, Histograms are almost flat indicating the equiprobable distribution of pixels. Also, Entropy of the encrypted image is close to 8 and Correlation coefficient value is very negligible indicating that neighboring pixels are heavily uncorrelated. As the key sequence based on Chaotic functions is sensitive to initial conditions, the sequence generated will be highly nonlinear and random which encourages one to use in cryptographic applications.

Image encryption scheme based on 3D baker with dynamical compound chaotic sequence cipher generator

This paper proposes a novel image block encryption algorithm based on three-dimensional Chen chaotic dynamical system. The algorithm works on 32-bit image blocks with a 192-bit secret key. The idea is that the key is employed to drive the Chen’s system to generate a chaotic sequence that is inputted to a specially designed function G, in which we use new 8x8 S-boxes generated by chaotic maps (Tang, 2005). In order to improve the robustness against differental cryptanalysis and produce desirable avalanche effect, the function G is iteratively performed several times and its last outputs serve as the keystreams to encrypt the original image block. The design of the encryption algorithm is described along with security analyses. The results from key space analysis, differential attack analysis, and information entropy analysis, correlation analysis of two adjacent pixels prove that the proposed algorithm can resist cryptanalytic, statistical and brute force attacks, and achieve a higher level of security. The algorithm can be employed to realize the security cryptosystems over the Internet.

Chaotic maps have gained popularity in image encryption models due to their ability to secure images with a random key.Further, the randomness of the key is highly dependent on the initial parameter values of the chaotic map.Therefore, the literature employs metaheuristic algorithms to find the optimal parameter values for generating a completely random key.Two chaotic maps-the 1-D chaotic logistic map (CLM) and the chaotic tent map (CTM)-along with the metaheuristic algorithm known as one-to-one-based optimization (OOBO) were used to create an optimized image encryption (IE) model in this study.We utilize the 1-D CLM algorithm for random key generation, while the 1-D CTM algorithm generates the shuffling sequence for image shuffling.We use the metaheuristic OOBO algorithm in both chaotic maps to generate completely random keys and random shuffling sequences based on the objective function.In this research, we design the objective function using security parameters such as entropy (E) and correlation coefficient (CC).After determining the optimal parameter values for chaotic maps, we perform an exclusive-OR operation between the random key and the secret image.After that, shuffling of the secret image is done based on the shuffling sequence given by the 1-D CTM algorithm.We evaluate the proposed IE model through simulation using images from the primary and secondary datasets.Using various parameters, we compare the visual quality of the encrypted image with the secret image in this evaluation.The results illustrate that the proposed IE model outperforms in terms of entropy and correlation coefficients and provides better encryption than the existing IE models.The proposed model achieves an entropy of 7.99648 for the cameraman, 7.99688 for Elaine, and 7.99704 for the pepper image.Further, a correlation coefficient of 0.00021 for the cameraman, -0.00012 for Elaine, and -0.00161 for the pepper image.

Blockchain is an up-and-coming technology, and it is exploring its existence in all our day-to-day lives, particularly for business applications. Due to this, security has become a major and a higher priority concern during the transaction process of data, cryptocurrency, etc. Achieving integrity, authentication, and non-repudiation with blockchain technology through digital signatures are the factors for its success. Hence, we imply a novel hybrid chaotic map–based proactive RSA/digital signature scheme for a better securable transaction of blocks compared to earlier works. Faster encryption and decryption could be expected by this novel approach. This could surely be resistant to brute force attacks, chosen plain text attacks and chosen cipher text attacks. OPENMP and OPENSSL libraries could be employed for good performance and security in a multicore platform. Chaotic map theory has its unique characteristics in the design of highly secure asymmetric encryption and decryption processes, with lesser computational cost in lesser time. The strength of RSA lies in the prime factorization of larger prime numbers in the generation of public and private keys. RSA has a severe backlog in computational time; while the length of the prime number is longer, to ensure higher security, the longer one is preferable. Hence to speedup the factorization process, chaotic mapping theory has been synchronized with the RSA cryptosystem. Second, chaotic mapping theory provides an enhanced avalanche effect, which leads to a two-factor RSA encryption process. Chaotic maps are highly sensitive to initial values and control parameters. The unique feature of inclusion of chaotic maps is that any slight change in the initial conditions of the plain text would cause a remarkable deviation in the message digest. This nature would make the hacker limit their prediction ability. Computational time, cost, and level of resistance to attacks are the factors to be considered to measure the efficiency of our new approach when compared to other RSA approaches. The work was simulated using MATLAB and it is proved that that the proposed RSA with hybrid GLT chaotic maps is 1.53 times and 1.27 times faster than the existing ones.

Image encryption has been an attractive research field in recent years. The chaos-based cryptographic algorithms have suggested some new and efficient ways to develop secure image encryption techniques. This paper proposes a novel image encryption scheme, which is based on the chaotic tent map. Image encryption systems based on such map show some better performances. Firstly, the chaotic tent map is modified to generate chaotic key stream that is more suitable for image encryption. Secondly, the chaos-based key stream is generated by a 1-D chaotic tent map, which has a better performance in terms of randomness properties and security level. The performance and security analysis of the proposed image encryption scheme is performed using well-known ways. The results of the fail-safe analysis are inspiring, and it can be concluded that the proposed scheme is efficient and secure.