Cipher Image Research Articles

An Effective Color Image Encryption Based on Henon Map, Tent Chaotic Map, and Orthogonal Matrices.

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.

Image encryption scheme based on blind signature and an improved Lorenz system

In this paper, a new improved Lorenz system (ImproLS) is designed with a better behavior due to a larger positive Lyapunov exponent. Then, an asymmetric image encryption scheme is presented based on blind signature and the ImproLS. First, the sender uses the public key from the receiver to produce the cipher keys in conjunction with the Rivest–Shamir–Adleman (RSA) algorithm. Then, a new mathematical model is established to convert both the plain keys and the cipher keys to generate the initial values for ImproLS. After doing preprocess to the secret plain image, its statistical characteristics is changed greatly. Then, by employing permutation and diffusion operations, the cipher image can be obtained and sent to the receiver and the signer. Second, the signer encrypts the digital signature image using Arnold transform in conjunction with the RSA algorithm, and applies the discrete wavelet transform (DWT) to the cipher image. The scrambled signature image is then embedded into the wavelet domain of cipher image blindly. Then, the cipher image containing signature is sent to the receiver for authentication. Third, the receiver uses the private key to check the signature and recover the cipher image. After comparing the decrypted images from both the sender and the signer, the receiver can judge the source of the secret plain image. Experimental results show that the information entropy is high and closer to the theoretical value. In addition, both unsigned and signed cipher images can effectively resist salt and pepper attack, and clipping attack.

A Probabilistic Chaotic Image Encryption Scheme

This paper proposes a probabilistic image encryption scheme that improves on existing deterministic schemes by using a chaining mode of chaotic maps in a permutation-masking process. Despite its simplicity, the permutation phase destroys any correlation between adjacent pixel values in a meaningful image. The masking phase, however, modifies the pixel values of the image at hand using pseudorandom numbers with some other initiated random numbers so that any slight change in the plain image spreads throughout the corresponding cipher image. These random numbers ensure the generation of distinct cipher images for the same plain image encryption, even if it is encrypted multiple times with the same key, thereby adding some security features. Simulations show that the proposed scheme is robust to common statistical and security threats. Furthermore, the scheme is shown to be competitive with existing image encryption schemes.

A Visually Secure Image Encryption Based on the Fractional Lorenz System and Compressive Sensing

Recently, generating visually secure cipher images by compressive sensing (CS) techniques has drawn much attention among researchers. However, most of these algorithms generate cipher images based on direct bit substitution and the underlying relationship between the hidden and modified data is not considered, which reduces the visual security of cipher images. In addition, performing CS on plain images directly is inefficient, and CS decryption quality is not high enough. Thus, we design a novel cryptosystem by introducing vector quantization (VQ) into CS-based encryption based on a 3D fractional Lorenz chaotic system. In our work, CS compresses only the sparser error matrix generated from the plain and VQ images in the secret generation phase, which improves CS compression performance and the quality of decrypted images. In addition, a smooth function is used in the embedding phase to find the underlying relationship and determine relatively suitable modifiable values for the carrier image. All the secret streams are produced by updating the initial values and control parameters from the fractional chaotic system, and then utilized in CS, diffusion, and embedding. Simulation results demonstrate the effectiveness of the proposed method.

Verifiable visually meaningful image encryption based on compressed sensing (CS) and improved game of life (IGOL)

Image encryption converts the plain image into a noise-like one to protect information security. However, the obtained cipher images are easy to attract the attention of third parties during transmission and storage, and it is vulnerable to information damage and tampering caused by hacking or noise pollution, which in turn makes the receiver unable to obtain the correct decrypted image even spending many resources. To address these issues, this paper proposed a verifiable visually meaningful image encryption based on compressed sensing (CS) and improved game of life (IGOL). Specifically, the plain image is preprocessed and compressed to obtain compressed image via CS, achieving the purpose of reducing the image size. Subsequently, to improve the encryption effect, dynamic cyclic shift confusion method (DCSCM) and diffusion method based on improved game of life (DMIGOL) are presented and performed on the compressed image to obtain the secret image. Next, multiple shadow images are obtained using the secret image sharing based on the Chinese remainder theorem (CRT-SIS) on the secret image, which improves the robustness of this scheme and achieves multi-party data transfer of image. Finally, the shadow images are embedded into the carrier images respectively to obtain visually meaningful cipher images, reducing the attacker's attention to the cipher images during transmission. Additionally, the Hamming distance authentication method relying on plain image and carrier image is applied, and users can perform identity authentication and integrity check on cipher image. Experimental results demonstrate the security and effectiveness of the proposed scheme.

Compressive Imaging Encryption with Secret Sharing Metasurfaces

AbstractExploiting various degrees of freedom of light, metasurfaces have unique advantages in multiple‐channel information storage and demonstration, which thereby provides a novel platform to convey the keys and cipher images for different encryptions. Following the secret sharing principle of visual cryptography (VC), the authors here successfully embed both the keys and cipher images of computational ghost imaging (CGI) encryption into the holographic metasurface‐images (meta‐images). The decryption process starts with key retrieval via optical observation of overlapped meta‐images, followed by a compressive CGI calculation to reconstruct the target images according to the obtained key and steganographic cipher images with a high compression ratio of 4. By integrating metasurface imaging, VC, and CGI, the authors’ proposed encryption scheme exempts conventional key distribution and transmission of CGI, enhances the security by secret sharing of VC, and increases the amount of hiding data contained in meta‐images with compressive sensing.

Blockchain enabled optimal Hopfield Chaotic Neural network based secure encryption technique for industrial internet of things environment

Industrial Internet of Things (IIoT) denotes a network of interlinked sensors, instruments, and other devices for industrial applications in the domains of manufacturing, logistics, transportation, etc. IIoT security is a major crucial research area for several applications. Image encryption techniques gained popularity in the recent years, thanks to increasing requirements for secure image transmission in IIoT environments. At the same time, conventional security solutions built for sensitive data protection are getting outdated in IIoT environment due to the participation of third party. Blockchain (BC) is one of the recent solutions used for security purpose which eliminates the involvement of a third party. With this motivation, the current research article presents a new BC-Enabled Shark Smell Optimization with Hopfield Chaotic Neural Network (SSO-HCNN) for secure encryption in IoT environment. The proposed SSO-HCNN model exploits a composite Chaotic Map (CM) which is integrated into staged logistic and tent maps to initially process the images and develop the variables needed for Arnold mapping. In addition, the SSO algorithm is developed with maximum PSNR and coefficient fitness function to select the optimum secret and public keys of the system amongst the random numbers. Besides, the diffusion phase utilizes HCNN to create a self-diffusion chaotic matrix whereas the jumbled image performs XOR operation using the keys to obtain the cipher image. In SSO-HCNN model, the cryptographic pixel value in the image is saved on BC thus guaranteeing the security and privacy of the images. To examine the superior performance of SSO-HCNN model over state-of-the-art methods, a set of simulations was conducted on benchmark test images. The simulation results of the proposed SSO-HCNN model were promising under different evaluation parameters.

Detecting the Security Level of Various Cryptosystems Using Machine Learning Models

With recent advancements in multimedia technologies, the security of digital data has become a critical issue. To overcome the vulnerabilities of current security protocols, researchers tend to focus their efforts on modifying existing protocols. Over the last few decades, though, several proposed encryption algorithms have been proven insecure, leading to major threats against important data. Using the most appropriate encryption algorithm is a very important means of protection against such attacks, but which algorithm is most appropriate in any particular situation will also be dependent on what sort of data is being secured. However, testing potential cryptosystems one by one to find the best option can take up an important processing time. For a fast and accurate selection of appropriate encryption algorithms, we propose a security level detection approach for image encryption algorithms by incorporating a support vector machine (SVM). In this work, we also create a dataset using standard encryption security parameters, such as entropy, contrast, homogeneity, peak signal to noise ratio, mean square error, energy, and correlation. These parameters are taken as features extracted from different cipher images. Dataset labels are divided into three categories based on their security level: strong, acceptable, and weak. To evaluate the performance of our proposed model, we have performed different analyses (f1-score, recall, precision, and accuracy), and our results demonstrate the effectiveness of this SVM-supported system. INDEX TERMS Support vector machine (SVM), security analysis, image encryption, cryptosystem.

Preserving privacy while revealing thumbnail for content-based encrypted image retrieval in the cloud

Owing to the rapid development of cloud services and personal privacy requirements, content-based encrypted image retrieval in the cloud has been increasing. Outsourced images are encrypted into noiselike ones to protect privacy, however, the obtained unrecognized appearance limits their availability. Besides, users have to decrypt all search results to browse, while some of them may not be needed, which undoubtedly wastes bandwidth and computing resources. To cope with this problem, a compromise strategy is proposed that considers the tradeoff between privacy and usability of cipher images. Wherein, a thumbnail preserving encryption (TPE) based on genetic algorithm is proposed. The pixels in the sub-blocks of the plain image are scrambled and diffused at the bit-level through crossover and mutation operators of the genetic algorithm. Moreover, two new operators of Mutation Compensation and Mutation Failure are defined and incorporated into the traditional genetic algorithm to achieve an ideal TPE, that cipher image has the same thumbnail as the original image. Additionally, a color histogram-based retrieval algorithm is introduced to retrieve cipher images using the color information preserved by thumbnails; and to improve retrieval accuracy by using the Bhattacharyya distance. A series of simulations verify the security and effectiveness of our scheme.

Optical asymmetric single-channel cryptosystem based on QZ synthesis for color images

In this paper, we propose an optical asymmetric single-channel cryptosystem based on QZ synthesis (QZS) for color images. In our cryptosystem, a QZS method for synthesizing color image into the grayscale image is proposed for the first time, thus realizing single-channel encryption. Then the synthesized image is modulated with the random phase masks, and transformed in the Gyrator domain to obtain the cipher image. With the QZS, our cryptosystem can achieve asymmetric and single-channel encryption. Compared with the existing phase truncated-based cryptosystems, our cryptosystem can improve security against the special attack. Numerical simulation results demonstrate the feasibility and robustness of our cryptosystem for encrypting one or even multiple color images.

Fast and Efficient Data Masking Method for Securing Image Over Cloud Computing Environment

Objective: Preserving the confidentiality of sensitive information is becoming more and more difficult and challenging, considering current scenarios, as a huge amount of multimedia data are stored and communicated over the internet among users and cloud computing environment. The existing cryptography security model for storing images on a cloud platform cannot resist various kinds of modern attacks, such as statistical, differential, brute force, cropping attack, etc., therefore, an improved bit scrambling technique using chaotic maps that can resist various kinds of security attacks is needed. The FEDM cipher image provides less correlation among neighboring pixels and images can be decrypted even under the presence of noise. This study proposed a FEDM model to achieve better UACI, NPCR, histogram, runtime, and processing time performance than the existing image security methods. Methods: Preserving the confidentiality of sensitive information is becoming more and more difficult and challenging considering current scenarios as a huge amount of multimedia data are stored and communicated over the internet among users and cloud computing environment. The existing cryptography security model for storing images on a cloud platform cannot resist various kinds of modern attacks such as statistical, differential, brute force, cropping attack, etc. Results: The overall results show that the proposed FEDM model attains much superior performance considering histogram, UACI, NPCR, and runtime. The FEDM model can resist against SA. The FEDM model attains better performance because IBS is used in each step of CS. Thus, a correlation between adjacent pixels is less and aids superior security performance. Further, the FEDM model attains better UACI and NPCR performance when compared with the exiting image encryption model. Conclusion: The FEDM security method can resist DA, noise, cropping attack, and linear attacks more efficiently due to a larger keyspace. Further, the FEDM takes less time for provisioning security. Along with this, FEDM works smoothly under a cloud computing environment. No prior work has considered runtime performance evaluation under the cloud computing environment. FEDM model will significantly aid in reducing the overall operational cost of a cloud computing environment with a reduction in processing time as cloud charge is based on hours of usage.

A Survey on Multidimensional Chaotic Maps and Genetic Operator

Abstract: The image encryption and decryption is the one of the ways to providing security to digital image. Encryption technique is a process of converting plain image into a cipher image. Decryption technique is a process of converting cipher image into a plain image. In this paper a survey of several multidimensional chaotic maps along with genetic operator were used in order to secure an image are discussed and along with the advantages and disadvantages of those maps. Keywords: Chaotic system, Chaotic maps, 1-dimensional logistic map,2-dimensional henon map,3-dimensional chebyshev map.

Efficient Hyperchaotic Image Encryption Algorithm Based on a Fast Key Generation Method and Simultaneous Permutation-Diffusion Structure

To provide faster encryption speed for protecting image data privacy, a highly efficient hyperchaotic image encryption algorithm using a fast key generation method and simultaneous permutation-diffusion structure is proposed in this paper. Firstly, we design a novel fast key generation method to obtain four key matrixes with the size of W × H (W and H are the width and height of an image) with the hyperchaotic Lorenz system only iterating 2W times. And within the key generation process, the piecewise linear chaotic map serves as a random selector to further enhance the randomness and unpredictability. Secondly, we introduce vectorization technique to parallelize the cipher blockchain-based encryption process. Hence, an image can be fast and sufficiently encrypted row by row and column by column through a four-round and interlinked diffusion process. Furthermore, during the diffusion process, the pixels are simultaneously scrambled by the Chebyshev map to enhance the antiattack capability of the proposed algorithm. Thirdly, we utilize a secure hash function to generate a plaintext-related secret key. Finally, cipher images can successfully pass common security tests with the correlation coefficients on the verge of 0, the entropies are greater than 7.99, and NPCR and UACI values are close to the expected values. Combined with other experimental results and analysis, we can safely conclude that the proposed algorithm has strong robustness against statistical, brute-force, differential, and some other common attacks. Moreover, only 0.009 s of encrypting a 256 × 256 image indicates that our algorithm has extensive application prosperity for real-time communications of massive digital images.

A Novel Image Encryption Scheme Based on Elliptic Curves over Finite Rings.

Image encryption based on elliptic curves (ECs) is emerging as a new trend in cryptography because it provides high security with a relatively smaller key size when compared with well-known cryptosystems. Recently, it has been shown that the cryptosystems based on ECs over finite rings may provide better security because they require the computational cost for solving the factorization problem and the discrete logarithm problem. Motivated by this fact, we proposed a novel image encryption scheme based on ECs over finite rings. There are three main steps in our scheme, where, in the first step, we mask the plain image using points of an EC over a finite ring. In step two, we create diffusion in the masked image with a mapping from the EC over the finite ring to the EC over the finite field. To create high confusion in the plain text, we generated a substitution box (S-box) based on the ordered EC, which is then used to permute the pixels of the diffused image to obtain a cipher image. With computational experiments, we showed that the proposed cryptosystem has higher security against linear, differential, and statistical attacks than the existing cryptosystems. Furthermore, the average encryption time for color images is lower than other existing schemes.

Optimal Multikey Homomorphic Encryption with Steganography Approach for Multimedia Security in Internet of Everything Environment

Recent developments of semiconductor and communication technologies have resulted in the interconnection of numerous devices in offering seamless communication and services, which is termed as Internet of Everything (IoE). It is a subset of Internet of Things (IoT) which finds helpful in several applications namely smart city, smart home, precise agriculture, healthcare, logistics, etc. Despite the benefits of IoE, it is limited to processing and storage abilities, resulting in the degradation of device safety, privacy, and efficiency. Security and privacy become major concerns in the transmission of multimedia data over the IoE network. Encryption and image steganography is considered effective solutions to accomplish secure data transmission in the IoE environment. For resolving the limitations of the existing works, this article proposes an optimal multikey homomorphic encryption with steganography approach for multimedia security (OMKHES-MS) technique in the IoE environment. Primarily, singular value decomposition (SVD) model is applied for the separation of cover images into RGB elements. Besides, optimum pixel selection process is carried out using coyote optimization algorithm (COA). At the same time, the encryption of secret images is performed using poor and rich optimization (PRO) with multikey homomorphic encryption (MKHE) technique. Finally, the cipher image is embedded into the chosen pixel values of the cover image to generate stego image. For assessing the better outcomes of the OMKHES-MS model, a wide range of experiments were carried out. The extensive comparative analysis reported the supremacy of the proposed model over the rennet approaches interms of different measures.

Reversible data hiding in encrypted images without additional information transmission

Reversible data hiding in encrypted images (RDHEI) is an essential branch of image reversible data hiding. Over the past decade, many significant achievements have been made. However, for most RDHEI researches, the cloud service user (CSU) demands either an encryption method specified by the cloud service provider (CSP) or prior knowledge about the original image to indicate the preprocessing operation. This characteristic may lead to some security issues like information leakage that may limit the use of this type of technology. To solve this problem, we propose a simple but effective RDHEI method that separates the CSU and CSP. The owner CSU exclusively sends the standard stream cipher image to the CSP, while the CSP can embed message data into the encrypted image through a simple MSB replacement without knowing the encrypted method or prior knowledge about the original image. The embedded message data can be extracted; meanwhile, the image can be approximately recovered by another authentic CSU. Since the proposed fundamental method is not error-free in most circumstances, we provide an alternative option to achieve reversibility by transmitting a perfect recovery key from the owner CSU to any authentic CSU. The experimental results demonstrate the efficacy of the proposed method.

Security Improvement Of Aes Algorithm Using S-Box Modification Based On Strict Avalanche Criterion On Image Encryption

Communication is something that cannot be separated from humans as social creatures. Images are the most commonly used visual communication in today's era. On the other hand, sending images via wireless networks is very vulnerable to piracy. AES, as one of the best cryptographic algorithms, can be applied as a solution. Even so, the AES algorithm still has weaknesses, which are weak against linear attacks and differential cryptanalysis. One solution to overcome the weaknesses of the AES algorithm is to use a stronger S-box. One of the methods to measure the strength of an S-box is the Strict Avalanche Criterion (SAC). The dataset is divided into four categories based on the image type and size of the pixels. Data that has been encrypted using the proposed algorithm will be compared with data that has been encrypted using the standard AES algorithm. Cipherimages (encrypted data) are tested using histogram analysis, information entropy, and sensitivity analysis. The results obtained from cipher image testing are differences in histogram analysis testing in grayscale and color images. The information entropy value is 0.000131583% better than the AES standard, the NPCR is 0.17613% better than the AES standard, and the UACI value. 0.211148% better than AES standard in sensitivity analysis testing. Based on these data, the proposed algorithm has a higher level of security than the standard AES algorithm on image encryption.

IEHC: An efficient image encryption technique using hybrid chaotic map

Image encryption is essential for the transmission of the sensitive images through insecure channels used in wired or wireless communication nowadays. With the advent of cloud enabled surveillance applications, Internet of Things applications, social media communications, the requirement of image encryption is also increasing day by day. The conventional encryption schemes demand high resources in terms of processing power, memory and bandwidth resulting degradation in overall system response time. In this paper, first a novel shuffling technique has been introduced to shuffle the pixels of an input color image. Subsequently, this paper proposes an image cipher that uses Logistic map and Arnold's cat map for encryption of color images. The experimental results and various security analyses exhibit good security characteristics and also prove its robustness against various types of noises, data loss and cryptanalysis attacks, making it appropriate for implementing in real-time applications.

SELECTIVE CHAOTIC GENERATION AND MULTI-MODALITY DIGITAL IMAGE CRYPTO SYSTEM USING HAAR WAVELETS

The importance of secured image transmission plays a significant role in this information era. The hackers hack the medical data in the form of images that costs more in terms of claiming insurances. It is necessary to secure the images that cannot be accessed by the unauthorized persons. Among the many types of image crypto systems, the chaos based image crypto systems is best known for its key insensitive to attack or hacking. The properties of the chaos play a major role in the generation of key for the secured transmission and reception. The Haar wavelet transform is yet simpler transform used to compress the input image in terms of approximate and detailed coefficients. The incorporation of the key in the approximate coefficients of the input image provides an efficient encryption when compared to other image crypto schemes. The encryption quality is evaluated using the histogram analysis of the encrypted of cipher image with different keys generated using respective chaotic maps. The framed image crypto system is designed and simulated using MATLAB software package. KEYWORDS: image cryptosystems, chaos theory, Haar wavelet transform, encryption, key generation.

Combined Steganography and Image Cryptography System for Secure Data Transfer

With billions of active internet users every given moment, user data privacy is vulnerable to potential attackers, so secure digital transmissions have always been a concern. With numerous researches going on in the field of cryptography systems there is always search new methods that can improve security of data sent over the internet. In this project a model is being designed with integrated various cryptographic techniques to make a hybrid crypto system for more reliable secure digital transmission. This project incorporates plain text cryptography, image steganography, and visual cryptography to encrypt a text all the way through getting an image that is distorted with hidden data inside. The primary step is to convert the plain text to cipher text using a symmetric cryptography algorithm, then using the method of steganography the cipher text is hidden inside the image and finally the concept of image cryptography is used to get a cipher image with encryption keys that encrypted the same. This project is going to be developed to accept globally spoken English language.