Proposed Image Encryption Algorithm Research Articles

Fast and Efficient Image Encryption Algorithm Based on Modular Addition and SPD.

Bit-level and pixel-level methods are two classifications for image encryption, which describe the smallest processing elements manipulated in diffusion and permutation respectively. Most pixel-level permutation methods merely alter the positions of pixels, resulting in similar histograms for the original and permuted images. Bit-level permutation methods, however, have the ability to change the histogram of the image, but are usually not preferred due to their time-consuming nature, which is owed to bit-level computation, unlike that of other permutation techniques. In this paper, we introduce a new image encryption algorithm which uses binary bit-plane scrambling and an SPD diffusion technique for the bit-planes of a plain image, based on a card game trick. Integer values of the hexadecimal key SHA-512 are also used, along with the adaptive block-based modular addition of pixels to encrypt the images. To prove the first-rate encryption performance of our proposed algorithm, security analyses are provided in this paper. Simulations and other results confirmed the robustness of the proposed image encryption algorithm against many well-known attacks; in particular, brute-force attacks, known/chosen plain text attacks, occlusion attacks, differential attacks, and gray value difference attacks, among others.

Designing a 2D infinite collapse map for image encryption

Due to the unpredictability and complexity properties, chaotic maps are widely applied in security, communication, and system control. Existing one-dimensional (1D) chaotic maps can be easily predicted and high-dimensional (HD) ones have more complex structures and higher computation costs. In order to enhance the chaotic performance, this paper proposes a new two-dimensional infinite collapse map (2D-ICM). Compared with existing 2D chaotic maps, 2D-ICM has better ergodicity, hyperchaotic property, unpredictability, and a wider chaotic region. To investigate its application, we further propose an image encryption algorithm using 2D-ICM. Simulation demonstrates that the proposed image encryption algorithm has excellent performance for protecting various kinds of images.

A New Fuzzy-DNA Image Encryption and Steganography Technique

Image encryption and steganography techniques are receiving a lot of interest and investigations due to their high importance in multimedia communication systems. A novel highly efficient image encryption and steganography technique are presented in this paper. For the first time, the proposed technique uses hybrid DNA encoding and Choquet's Fuzzy Integral sequences. At first, a confused version of the image, using a simple chaotic map, is encoded using DNA's bases. Four coded images are generated using the four DNA bases, namely AT, CG, GC, and TA. Parallel to that, a Choquet's fuzzy Integral sequence is generated and DNA encoded similarly to obtain four pseudo-random sequences. Secondly, the resulting four fuzzy/DNA sequences are used to diffuse the four DNA encoded images using the complementary DNA XOR rule, according to certain control code. Finally, the wavelet fusion algorithm is then used to fuse the resulting four fuzzy-DNA encoded images, to get the encrypted image. For added security, a new steganography approach is used. In particular, the encrypted image is divided into four sub-images, each of which is hidden in a different carrier image selected from a known group of carrier images according to a given key. The simulation results and security analysis confirmed the efficiency of the proposed image encryption algorithm as well as the steganography approach used for enhanced security. Ten different images with a size of 256 x 256 are used to test the proposed method. The results show that the proposed algorithm has a higher key sensitivity. The pixel correlation coefficient values are very small (between 5.3220e-04 and 0.0011 horizontally, between 8.7670e-04 and 0.0022 vertically and between 0.0002 and 0.0045 diagonally). Furthermore, the measured information entropy of the encrypted images is between 7.9970 and 7.9979 which are very close to the ideal value of 8. Additionally, the measured unified average changing intensity and number of pixels change rate values take the values between 33.46 and 33.39 and between 99.61 and 99.64, respectively, which are again closed to the ideal values. The steganography test shows that the hidden encrypted images are almost invisible at high values of SNR and are characterized by good NCC values under different types of attacks. The performance of the new proposed algorithm is proved to overcomes many other previously published image encryption techniques.

Optical image encryption scheme based on apertured fractional Mellin transform

An optical image encryption scheme is proposed by utilizing an apertured nonlinear fractional Mellin transform (FrMT). Due to its nonlinear property, FrMT is utilized for eliminating potential insecurity in an image encryption system caused by known-plaintext and chosen-plaintext attacks. The aperture in the optical system makes it harder for attackers to collect optical signals in the transmission process. The apertured FrMT can be implemented by log-polar transform and Collins diffraction and the key space of the proposed image encryption algorithm is very large. The orders of the FrMT, the radii of the FrMT domains, the order of the FrFT, the phases generated in the further encryption process, wavelength, side-lengths of hard aperture, and the parameters of logistic map are used as cipher keys. Extensive simulation results demonstrate that the proposed algorithm is feasible, sensitive to the keys, and capable of resisting common classical attacks. The encryption effect changes with the size of apertures.

Image encryption algorithm based on discrete logarithm and memristive chaotic system

In order to effectively resist the plaintext attacks introduced in recent cryptanalysis literatures, a reformative image encryption algorithm based on discrete logarithm and a memristive chaotic system is proposed in this paper. Firstly, we realize the permutation and confusion of a plain image by employing the discrete logarithms of memristive chaotic sequences. Then the discrete logarithms of intermediate cipher pixels and memristive chaotic sequences are used in the forward diffusion and backward diffusion of the permuated and confused image. Since the finite multiplication group adopted in this paper has up to 128 generators, we can expand the secret key space and enhance the ability of the proposed image encryption algorithm to resist plaintext attacks, by obtaining the generators through the secret key and the SHA256 hash value of the plain image. Finally, Simulation results and comparative analyses show that the proposed image encryption algorithm is not only secure and efficient, but also has very high practical value.

Optical image encryption algorithm based on phase-truncated short-time fractional Fourier transform and hyper-chaotic system

To increase the robustness against common attacks, a novel image encryption algorithm is proposed based on the phase-truncated short-time fractional Fourier transform (PTSTFrFT) and the hyper-chaotic system. In the algorithm, the original image is divided into four sub-images to be encoded independently. Different from the traditional phase truncation coding, the PTSTFrFT is combined with wave-based permutation to construct the encryption unit (EU) for encoding the sub-images, where the confused phase information is recombined with the amplitude information to guarantee the integrity of image information and the nonlinearity of phase truncation. Besides, the encryption unit can be achieved optically. Furthermore, the corresponding results compose an interim image, whose pixel values and pixel positions are modified by the permutation and the diffusion operations. The diffusion operation is designed with the feedback system to increase the anti-interference ability. The proposed image encryption algorithm has large enough key space and high sensitivity to the keys because of the use of hyper-chaotic system. The simulation results demonstrate that the proposed image encryption algorithm based on the PTSTFrFT is secure and robust enough against the common attacks.

High-sensitivity image encryption algorithm with random diffusion based on dynamic-coupled map lattices

This paper proposes a new high-sensitivity image encryption algorithm with random diffusion based on the spatiotemporal chaos of the Logistic-dynamic mixed linear-nonlinear coupled map lattices (LDMLNCML). The proposed LDMLNCML system possesses prominent cryptographic characteristics, which is very suitable for image encryption. The proposed image encryption algorithm adopts the strategy of random diffusion. Firstly, the pending sequence is generated according to the number of image pixels, and then two index chains are generated combining the conflict handling process. Finally, the cipher image is obtained by random diffusion. Index chains are highly sensitive to changes in position, and changes of the position of any one element will produce completely different index chains. The cipher value of each pixel in the diffusion phase depends on two random non-adjacent pixels and chaos interference value, which can greatly reduce the correlation between the adjacent pixels. Theoretical analysis and experimental results demonstrate the security and practicability of the cryptosystem.

Reality-Preserving Multiple Parameter Discrete Fractional Angular Transform and Its Application to Color Image Encryption

In this paper, we first define a reality-preserving multiple parameter fractional angular transform (RPMPDFrAT), which is a useful tool for image encryption. Then, we propose a new color image encryption algorithm based on the defined RPMPDFrAT. The encryption process consists of two phases: encryption in the spatial domain and RPMPDFrAT domain. In the spatial domain, three color components of the plain image are mapped by dual cylindrical transform, which can nonlinearly hide the original color information. Then, the intermediate output is scrambled by a coupled logistic map to reduce the correlation of adjacent pixels and uniformly distribute the image energy of different color components. Thereafter, the scrambled image is transformed by the proposed RPMPDFrAT, which can ensure that we obtain the real-value output. Finally, a process similar to the spatial domain is performed in the RPMPDFrAT domain to further improve the security of the cryptosystem. Numerical simulations are performed and demonstrate that the proposed image encryption algorithm is effective and sensitive to keys. Moreover, some potential attacks are tested to verify the robustness of the proposed method, and the performance of our method outperforms previously published ones.

Image Encryption Using Hyper-chaotic Map for Permutation and Diffusion by Multiple Hyper-chaotic Maps

In this paper, the image encryption using hyper-chaotic mapping for permutation and diffusion is proposed. 2D hyper-chaotic map is used to generate permutation order into scramble the image in the permutation stage itself. It is further diffused by multiple hyper-chaotic maps through Lorenz’s and Chen’s system. This scheme diffuses the permuted image drastically to bring about randomness characteristics. The permuted key streams get circularly shifted to generate a new key stream for diffusion. The diffusion key stream is generated by multiple hyper-chaotic maps for each step with respect to the input image. The proposed image encryption algorithm using multiple hyper-chaotic maps eliminates multiple rounds and encrypts the image in a single round. The performance analysis such as key space analysis, histogram analysis, correlation analysis, information entropy analysis, NCPR, UACI analysis etc., are carried out which yields better results and security. The proposed algorithm demonstrates the robust security and its validity.

A Fast Image Encryption Algorithm Based on Self-confusion Method

A novel image encryption algorithm based on self-confusion was proposed in this paper. The image encryption process is composed of covering operation, self-confusion and diffusion. The chaotic system was employed to generate one pseudo-random matrix and two pseudo-random sequences for image encryption. The matrix is used to cover the image, and the sequences are used to diffuse the image. The image is shuffled in the self-confusion by its own data, making the proposed image encryption algorithm be plaintext-related. The simulation results show that the proposed scheme has the merits of fast speed and good security, and can be a candidate for image information security.

Double-image encryption based on spatiotemporal chaos and DNA operations

A double-image encryption algorithm combining DNA insertion and deletion operations with spatiotemporal chaos is proposed. The technology of DNA sequence insertion and deletion is employed in both confusion and diffusion to encrypt two images simultaneously. In the proposed image encryption scheme, the key streams to control DNA operations are obtained by means of iterating the system of non-adjacent coupled map lattices (NCML). The original key streams are related to the plain-image, which increases the sensitivity of the proposed algorithm. Two confused images are served as keys to encrypt each other. The confused image is associated with another through the DNA insertion and deletion, which not only improves the security of image encryption system but also enhances the encryption speed. It is demonstrated that the proposed image encryption algorithm has the characteristics of large key space, high sensitivities of key and plain-image, and high entropy. Also, the proposed algorithm is robust to occlusion-attack and noise-attack. Therefore, the proposed double-image encryption algorithm is heuristic for the DNA computing applications into the multi-image encryption.

Image Encryption Algorithm with Plaintext Related Chaining

This paper describes a plaintext related image encryption algorithm that utilizes the Mojette transform for computation of bins that are subsequently combined with pixels of the processed image. While the bins are computed solely from pixel intensities of a plain image and also the combination depends only on intensities of plain image pixels, the parameters of bins are rearranged according to used key. This design results in a great sensitivity of the proposed image encryption algorithm to both plain images and keys, which is verified by a set of experiments. The paper also tests the resistance of the proposal against statistical and differential attacks by means of commonly used measures as correlation coefficients, entropy, NPCR and UACI. Furthermore, the paper analyses computation speed reached by the proposed solution. Computed values of all parameters are discussed and then compared with results obtained by some recent plaintext related image encryption algorithms.

Dynamical Analysis of a Novel Complex Chaotic System and Application in Image Diffusion

In this paper, a novel complex chaotic system is constructed. The characteristics of new complex chaotic system are analyzed by symmetric, dissipative and stability, then dynamical performances studied using bifurcation diagram, Lyapunov exponent spectrum and complexity. On the basis of this, an image diffusion algorithm is proposed based on the model of law of gravity. Security performances of the proposed algorithm are researched through the key space, statistics, information entropy, noise attack. The experimental results illustrates that the novel complex chaotic system has abundant dynamical behaviors and large parameters range, the security analysis shows that the proposed image encryption algorithm possess higher security features. Therefore, the research will provide theoretical guidance and experimental basis for chaotic secure communication and information security.

Efficient and Secure Image Encryption Algorithm Using a Novel Key-Substitution Architecture

Recently, many chaos-based image encryption algorithms have been proposed. Most of them adopt the traditional confusion-diffusion framework. Multiple encryption rounds or one round of complex encryption is typically executed in these schemes to realize high security. However, these operations will reduce the computational efficiency. To overcome these issues, we propose a novel key-substitution encryption architecture (KSA). Under the proposed KSA, we design a key scheming for updating the initial keys using the plain-image and develop a new substitution method for encrypting various types of images. The simulation results and security analysis demonstrate the superior security and high efficiency of the proposed image encryption algorithm using the KSA (KSA-IEA), which executes only one round of encryption.

Image Encryption using DNA Coding and Hyperchaotic System

ABSTRACTThe paper proposes a grey scale image encryption scheme using six-dimensional Lorenz chaotic system. The key generating system uses a 32 character (256 bits) key as input. The system uses simple modular arithmetic and bitwise XOR operations followed by coupling a series of Lorenz six-dimensional systems to generate the key-stream. This generated key stream is used in the encryption and decryption algorithm of the plain image. The basic permutation and diffusion architecture, using the fundamental properties of modular arithmetic, bitwise XOR operations and DNA encoding/decoding technique, are executed to confuse the relationship between plain image and the ciphered image. The experimental results and security tests confirm that the proposed image encryption algorithm possess high security and can be a good candidate for practical image encryption.

A new color image encryption algorithm based on DNA and spatial chaotic map

In this paper, a color image encryption algorithm based on DNA encoding combined with logistic map and spatial map is proposed. Firstly, the algorithm carries out scrambling by logistic map for R, G, B channels. Then, XOR is operated between channels pixel and sequence matrix controlled by spatial map. After that, realizes the addition of R, G, B by DNA addition after DNA encoding and carries out complement operation by using the DNA sequence matrix controlled by spatial map. What is more, R G B channel images are got after DNA decoding. Finally, gets the encrypted R, G, B images by reconstructing R, G, B components. The results of several experimental, statistical analysis and key sensitivity tests show that the proposed image encryption algorithm provides an efficient and secure way for real-time image encryption and transmission.

Bit-level plane image encryption based on coupled map lattice with time-varying delay

Most of the existing image encryption algorithms had two basic properties: confusion and diffusion in a pixel-level plane based on various chaotic systems. Actually, permutation in a pixel-level plane could not change the statistical characteristics of an image, and many of the existing color image encryption schemes utilized the same method to encrypt R, G and B components, which means that the three color components of a color image are processed three times independently. Additionally, dynamical performance of a single chaotic system degrades greatly with finite precisions in computer simulations. In this paper, a novel coupled map lattice with time-varying delay therefore is applied in color images bit-level plane encryption to solve the above issues. Spatiotemporal chaotic system with both much longer period in digitalization and much excellent performances in cryptography is recommended. Time-varying delay embedded in coupled map lattice enhances dynamical behaviors of the system. Bit-level plane image encryption algorithm has greatly reduced the statistical characteristics of an image through the scrambling processing. The R, G and B components cross and mix with one another, which reduces the correlation among the three components. Finally, simulations are carried out and all the experimental results illustrate that the proposed image encryption algorithm is highly secure, and at the same time, also demonstrates superior performance.

Finite-Time Projective Synchronization of Memristor-Based BAM Neural Networks and Applications in Image Encryption

Inspired by security applications in the image transmission, this paper focuses on the usage of chaotic properties of memristor-based bidirectional associate memory neural networks (MBAMNNs) for image encryption against illegal attack. A class of memristor-based bidirectional associate memory neural networks with delays and stochastic perturbations is formulated and analyzed. Based on drive-response concept, Ito’s differential formula and inequality technique, some sufficient criteria are obtained to guarantee the finite-time projective synchronization. In order to realize the image encryption, we propose a chaotic color image encryption algorithm based on MBAMNNs. Illustrative examples are provided to verify the developed finite-time projective synchronization results. And we also show the great chaotic properties of the models proposed in this paper. Analysis of the encryption effect demonstrated the security of the proposed image encryption algorithm, and the potential applications of our models in secure image transmission are analyzed.

Secure Image Encryption Based on an Ideal New Nonlinear Discrete Dynamical System

It is well known that encryption algorithms developed based on Logistic map suffer from limited key space due to the narrow regions of system parameters which can be used, potential risk of security in the presence of numerous periodic windows within the key space, and weakness in known-plain-text attack due to the inherent correlation among the chaotic sequence used for encryption. To overcome these existing problems, this paper presents a secure image encryption algorithm based on a new highly nonlinear discrete dynamical system with ideal chaotic characteristics. Transcendental functions are introduced together with modulo operations which physically represent discontinuous time-varying nonlinearities, leading to extremely complex chaotic behavior that is highly sensitive to system parameters and initial conditions, both of which are considered as the key for the cryptosystem. Extensive numerical experiment results have revealed that the proposed image encryption algorithm offers advantages of unlimited key space and high-level security, since those problematic periodic windows are no longer present within the key space, and it is extremely robust against known-plain-text attack, since the chaotic sequence generated bears no correlation whatsoever due to the folding effect of modulo operation. The algorithm makes truly efficient yet highly secure image encryption based on chaotic systems a reality.

A novel image encryption algorithm based on synchronized random bit generated in cascade-coupled chaotic semiconductor ring lasers

In this paper, a novel image encryption algorithm based on synchronization of physical random bit generated in a cascade-coupled semiconductor ring lasers (CCSRL) system is proposed, and the security analysis is performed. In both transmitter and receiver parts, the CCSRL system is a master-slave configuration consisting of a master semiconductor ring laser (M-SRL) with cross-feedback and a solitary SRL (S-SRL). The proposed image encryption algorithm includes image preprocessing based on conventional chaotic maps, pixel confusion based on control matrix extracted from physical random bit, and pixel diffusion based on random bit stream extracted from physical random bit. Firstly, the preprocessing method is used to eliminate the correlation between adjacent pixels. Secondly, physical random bit with verified randomness is generated based on chaos in the CCSRL system, and is used to simultaneously generate the control matrix and random bit stream. Finally, the control matrix and random bit stream are used for the encryption algorithm in order to change the position and the values of pixels, respectively. Simulation results and security analysis demonstrate that the proposed algorithm is effective and able to resist various typical attacks, and thus is an excellent candidate for secure image communication application.