Simplified and Effective Dual-Round Image Encryption Robust Technique

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.

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.

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.

This paper contrasts the implementation of several chaos-based digital image watermarking techniques in terms of imperceptibility, robustness, security and complexity. Most spatial and transform domains methods have been used namely Least Significant Bit (LSB), Discrete Cosine Transform (DCT), Discrete Wavelet Transform (DWT) and Redundant Discrete Wavelet Transform (RDWT) with Singular Value Decomposition (SVD) mathematical tool which has enhanced embedding capability. Both continuous and discrete chaotic maps namely Arnold's Chaotic Map (ACM), Logistic Chaotic map (LCM) and Lorenz Chaotic Map (LoCM) are included to result in secure schemes. Exhaustive series of tests have been performed along with a range of evaluation metrics for imperceptibility evaluation. In addition, Robustness of all the techniques has also been confirmed by applying a variety of attacks on the resulting images. This study will help to adopt the most suitable methods for a given application as sufficient number of test images have been utilized.

The Data Encryption Standard (DES) was a prevalent symmetric key block cipher scheme. It was the most popular used cryptographic algorithm. DES's security was a highly debatable aspect until it became an insecure algorithm in 1999. In this paper, an enhancement that overcomes the security weakness of DES is introduced. The modification employs the chaotic logistic map and the art of the Elliptic Curve Cryptography. The required key generation and distribution are achieved by the enhancement to establish a communication session. Our new DES is applied on image encryption and decryption processes. Experimental results are carried out with detailed analyses, the results demonstrate that the proposed scheme has an absolutely large key space to encounter the brute-force attack and it has a good immunity to the statistical attacks. Accordingly the introduced new DES algorithm could be used as a remarkably secure algorithm.

This paper offers a security analysis of an optical image cryptosystem that integrates interference and unequal modulus decomposition (EMD). In contrast to the conventional interference-based cryptosystem, which utilizes a single phase-only mask (POM) derived from the encryption process as the private key, the enhanced cryptosystem employs two random phase masks (RPMs) and two POMs derived from the phase-reserved (PR) structure as private keys. This modification addresses the silhouette problem inherent in the conventional interference-based cryptosystem by expanding the key space, thereby enhancing security strength. However, it is determined that the RPM R2(u,v) and the POM P2(x,y) exhibited low key sensitivity, thereby limiting their impact on the security enhancement. Additionally, due to the independence from the plaintext, the RPMs employed as private keys can be recovered using a designed known-plaintext attack (KPA). Once the RPMs are recovered, the number of unknown keys is reduced to two. This enables the recovery of plaintext information from its ciphertexts via a subsequent ciphertext-only attack (COA) without any prior knowledge of the POMs. In light of these findings, a novel hybrid attack strategy, to our knowledge, is proposed, integrating four cascaded KPAs and a COA, to effectively compromise the advanced interference and EMD-based cryptosystem. To validate the feasibility and effectiveness of the proposed hybrid attack, numerical simulations have been conducted.

With the rapid development of computer network technology, information security has attracted increasing attention. Due to the characteristics of multi-dimensional operation and parallel processing capability, optical image encryption techniques have been receiving more and more attention. Since the well-known double random phase encoding technique was proposed, many other methods based on optical information processing means such as the use of optical transform, interference, and polarized light encoding, have been proposed for optical image encryption. However, recent researches have demonstrated that traditional optical encryption techniques are symmetric cryptosystems, in which decryption keys are identical to encryption keys and they have been found to be vulnerable to different types of attacks, such as known plaintext and chosen plaintext attacks. To overcome this shortcoming, asymmetric cryptosystems based on nonlinear phase-truncation techniques and phase retrieval algorithm have been proposed. Asymmetric cryptosystem is a cryptographic system in which encryption keys are different from decryption keys. The encryption keys are used as public keys which are disseminated widely, and the decryption keys are used as private keys which are known only to the authorized users. So, asymmetric cryptosystem can offer a higher-level security than symmetric cryptosystem. However, asymmetric cryptosystems based on phase retrieval algorithms require a lot of computational time, and asymmetric cryptosystems based on phase-truncated Fourier transforms have been found to be vulnerable to special attack. Therefore, in this paper, a novel asymmetric image encryption method is proposed by using the gyrator transform and vector operation. The original image is encrypted into two phase masks with vector operation. One is a random phase mask and the other is a phase mask related to the original image. In the encryption process, the random phase mask is used as a phase key and the other phase mask is transformed by gyrator transform. The transform result is performed by Fourier transform after being modulated by a phase distribution. The ciphertext is the amplitude of the above result. Compared with previous encryption schemes, the suggested method has two advantages. Firstly, we have proposed a new asymmetric encryption method based on the gyrator transform and vector operation. The decryption process is different from the encryption process. The gyrator transform and Fourier transform are used in the encryption process, while only the inverse operation of Fourier transform is employed in the decryption process. In addition, the decryption keys produced in the encryption process are different from the encryption keys. Therefore, the proposed scheme has high resistance against the conventional attacks. Secondly, the encrypted result is real-valued, which is convenient for display, transmission and storage.Numerical simulations illustrate the feasibility and effectiveness of the proposed encryption scheme.

Communication is essential to every society, and securely exchanging data are critical in the age of digital data. The image has been the center of interest for security; chaotic maps image encryption become widely used in recent years. In our study, authors assessed the pixel rearrangement (permutation) and pixel dissemination (diffusion) stage used in cipher image established on designed scheme Pseudo-random number Generators (PRNGs) and Logistic chaotic map. Logistic maps used to generate seed value for PRNG and two-permutation stage and PRNGs used in diffusion operation. The proposed design through experimental tests demonstrate decent Statistical output, and high security for our image encryption schema, Our PRNGs passed NIST SP 800-22, and TestU01 practical randomness test suggests PRNGs have suitable statistical property.

Watermarking has become a crucial technique for protecting copyright and verifying the authenticity of images due to the rapid distribution of digital images and the ease and reliability of image content modification. In this research, we introduce a hybrid digital picture watermarking method that is both secure and resilient. This would use the discrete wavelet transform (DWT), the discrete cosine transforms (DCT), singular value decomposition (SVD), and cryptographic systems such as RSA and chaotic maps. Hence, this method tries to balance the tradeoff of robustness, security, and imperceptibility. We first encrypt the watermark using RSA, and then a chaotic logistic map (CLM) scrambles the already designed encrypted watermark to further enhance its robustness. By putting the watermark in the host image's separately calculated DWT-DCT coefficients, the proposed method works well even when compression, noise addition filtering, and geometric attacks are used. The test results demonstrate that the suggested method does better than other methods in Structural Similarity Index (SSIM), Normalized Correlation (NC), and Peak Signal-to-Noise Ratio (PSNR). Regardless of the nature of the attack, our proposed method consistently generates PSNR values above 55 dB and NC values above to 0.90, indicating correct watermark extraction and excellent image perception. We use cryptographic methods to secure the watermark from retrieval and modification by unauthenticated users. In addition, our approach is superior to the current watermarking methods in robustness and unobtrusiveness. In further works, we plan to improve the robustness of the approach against more complex geometric attacks and apply it for watermarking video and 3D content.

In recent years, because of the frequent flow of digital images across the world over the transmission media, image encryption become one of the most substantial topics. In this paper, we propose a new image encryption method based on the well-known Chaotic Logistic Map (CLM) and the Rivest Cipher 4 (RC4) encryption methods. Here, we use the secret key, and the CLM to produce a one-dimensional array of different numbers. Then the RC4 algorithms used to make some sort of random shuffling (relying on the contents of the array created by the CLM) to the array that is created by the RC4 first algorithm. After that, the second algorithm of RC4 used inside a loop to change the value of each color (using the resultant array of the first RC4 algorithm) of a pixel until all the pixels of the image be changed. And by doing that we have produced a cipher image that is completely different and does not reveal any information of the plain image, also we proved that it is really a key sensitive encryption that can't be decrypted easily by using brute force or any other kind of attacks.

An efficient and highly secure method of secret message cryptography will be presented which based on the principle of playing cards shuffling. The method will be implemented in a selected number of layers, each layer will encrypt-decrypt the input message using its own private key (PK), the output of any layer can be taken as a final encrypted-decrypted message, increasing the number of layers will increase the security level of the massage, making the hacking attacks impossible. In the encryption function a key generation and a message blocks shuffling will be executed, while in the decryption function the key generation and the message blocks reverse shuffling will be executed. The PK used in this method will be complicated and it will contain for each layer 2 chaotic parameters (r and x) and the block size (BS), utilizing these parameters, a chaotic logistic map model is run to produce a chaotic key, which is sorted to produce the layer's index key. Applying 4 layers the length of confidential key will be 768 bits, this length will be able to generate a large key space which is robust to hacking attempts. The speed parameters and throughput of the proposed will be calculated and compared with those of other methods.

A robust and secure chaotic standard map based pseudorandom permutation-substitution scheme for image encryption

New method for fingerprint images encryption using DNA sequence and chaotic tent map

Securing color image transmission using compression-encryption model with dynamic key generator and efficient symmetric key distribution

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.