Original Plaintext Image Research Articles

Recoverable Privacy-Preserving Image Classification through Noise-like Adversarial Examples

With the increasing prevalence of cloud computing platforms, ensuring data privacy during the cloud-based image-related services such as classification has become crucial. In this study, we propose a novel privacy-preserving image classification scheme that enables the direct application of classifiers trained in the plaintext domain to classify encrypted images without the need of retraining a dedicated classifier. Moreover, encrypted images can be decrypted back into their original form with high fidelity (recoverable) using a secret key. Specifically, our proposed scheme involves utilizing a feature extractor and an encoder to mask the plaintext image through a newly designed Noise-like Adversarial Example (NAE). Such an NAE not only introduces a noise-like visual appearance to the encrypted image but also compels the target classifier to predict the ciphertext as the same label as the original plaintext image. At the decoding phase, we adopt a Symmetric Residual Learning (SRL) framework for restoring the plaintext image with minimal degradation. Extensive experiments demonstrate that (1) the classification accuracy of the classifier trained in the plaintext domain remains the same in both the ciphertext and plaintext domains; (2) the encrypted images can be recovered into their original form with an average PSNR of up to 51+ dB for the SVHN dataset and 48+ dB for the VGGFace2 dataset; (3) our system exhibits satisfactory generalization capability on the encryption, decryption, and classification tasks across datasets that are different from the training one; and (4) a high-level of security is achieved against three potential threat models. The code is available at https://github.com/csjunjun/RIC.git .

The Coupling of a Multiplicative Group and the Theory of Chaos in the Encryptions of Images

This study is centered on a significant scientific contribution within the realm of image cryptography. The chosen approach involves employing the bidimensional Arnold Cat Map transformation to reposition and modify pixel locations, guided by parameters derived from the original image. The construction of the multiplicative group Z/nZ, comprising equivalence classes modulo n, relies on a hyper-chaotic sequence derived from the 2D sinusoidal logistic modulation map. The correlation between this sequence and the preceding step yields an unpredictable blurring pattern, effectively altering the statistical properties of resulting matrices and distributing the influence of individual bits across the entire encrypted image. For each pixel, the encryption process entails an XOR operation with the Z/nZ group, followed by a right shift based on the three Least Significant Bits (LSB) of the preceding pixel. This meticulous procedure is iterated for every pixel, leaving no trace of similarity or association with the original plaintext image, effectively rendering it blurred and indecipherable. To gauge the efficacy of our algorithm, we subjected it to thorough evaluation utilizing diverse criteria, including histogram analysis, which unveiled a nearly uniform pattern in the encrypted images. Entropy values were found to be close to 8, while the correlation analysis exhibited a pronounced proximity to 0. Moreover, we subjected our approach to differential attacks, and the calculated values of the Number of Changing Pixel Rate (NPCR > 99.6) and the Unified Averaged Changed Intensity (UACI > 33.2) corroborated the strength and resilience of our methodology. In addition, to establish its comparative standing, we undertook a comprehensive assessment, meticulously comparing our method to various existing approaches from the literature, including those proposed by Hua, Es-sabry, and Faragallah. This systematic process accentuated the high level of responsiveness and sensitivity inherent in our approach, thus underscoring its innovative and promising nature

Lossless Data Hiding in Encrypted Images Compatible With Homomorphic Processing.

Reversible data hiding in ciphertext has potential applications for privacy protection and transmitting extra data in a cloud environment. For instance, an original plain-text image can be recovered from the encrypted image generated after data embedding, while the embedded data can be extracted before or after decryption. However, homomorphic processing can hardly be applied to an encrypted image with hidden data to generate the desired image. This is partly due to that the image content may be changed by preprocessing or/and data embedding. Even if the corresponding plain-text pixel values are kept unchanged by lossless data hiding, the hidden data will be destroyed by outer processing. To address this issue, a lossless data hiding method called random element substitution (RES) is proposed for the Paillier cryptosystem by substituting the to-be-hidden bits for the random element of a cipher value. Moreover, the RES method is combined with another preprocessing-free algorithm to generate two schemes for lossless data hiding in encrypted images. With either scheme, a processed image will be obtained after the encrypted image undergoes processing in the homomorphic encrypted domain. Besides retrieving a part of the hidden data without image decryption, the data hidden with the RES method can be extracted after decryption, even after some processing has been conducted on encrypted images. The experimental results show the efficacy and superior performance of the proposed schemes.

Compressed phase coding-based optical image encryption

With the development of artificial intelligence technology, the traditional inflexible optical image encryption system has been difficult to resist security attacks such as chosen-plaintext attack and known-plaintext attack, and its security has been greatly challenged. Therefore, an optical image encryption method based on compressed phase coding is proposed, in which a spatial light modulator (SLM) is used to encode the phase of the optical system randomly, and then combined with the measurement matrix in the single pixel sampling process to build a flexible key system. In the encryption process, a phase-only SLM is firstly implemented to realize phase encoding of the original plaintext image and loading the phase key. Then the modulated reference light is implemented to further hide the complex amplitude distribution of the encrypted image. Finally, the encoded object light and reference light are coherently superimposed in the digital micromirror device (DMD), and the inner product operation is carried out with the measurement matrix to realize further encryption and collected by the single pixel detector. Both simulation and experiment proved that the proposed compressed phase coding-based image encryption system is similar to "one time one pad" cryptographic system, which greatly improves the security of the optical encryption system.

Encrypting Image by Lossless and Reversible Data Hiding using Cryptography

This paper proposes a lossless and reversible data hiding scheme for images by using chaotic system with the help of public key cryptography. In this system original grey scale image will be encrypted using shuffling and scrambling using double encryption via chaotic system. And encryption will not affect original grayscale image. With the help of this technique, a receiver may extract a part of embedded data before decryption, and extract another part of embedded data and recover the original plaintext image after decryption.

A chaotic image encryption algorithm based on random dynamic mixing

This paper proposes a new chaotic system, combined with the dynamic mixing of pixel values, pixel bits, and binary bits encryption algorithms, which are used together in image encryption. The whole process is as follows. First, the original plain text image is converted into an initial key through the SHA-512 algorithm and related operations, then the initial key is applied to the proposed delayed feedback dynamic mixed linear-nonlinear coupled mapping lattices (DFDMLNCML) to obtain the chaotic matrix required for encryption, next, perform the encryption operation of mixed pixel values, pixel bits and binary bits, scrambling and diffusion are done together to improve the security of the algorithm. Finally, the average NPCR, average UACI is 99.6075, 33.4795, respectively, experimental results and various security analyses show that the performance of the system and algorithm is good, and it can resist ordinary attacks, such as selecting plaintext attacks, cropping attacks, and noise attacks.

Chaos and compressive sensing based novel image encryption scheme

Out of various cryptographic attacks, Chosen-Plaintext Attack (CPA) is one of the most powerful and widely used attack on encrypted images. In order to efficiently resist such a strong attack, a novel chaos and compressive sensing based image encryption algorithm is presented in this work. Firstly, the original plaintext image is compressed via Orthogonal Matching Pursuit with Partially Known Support (OMP-PKS) and then the compressed image is confused and diffused using TD-ERCS and Skew-tent chaotic maps, respectively. Correlation among the compressed pixels is break down via confusing the image pixels using Tangent Delay Ellipse Reflecting Cavity Map System (TD-ERCS). Skew-tent chaotic map is employed for the pixel diffusion process. To get the final ciphertext image, the confused pixels are further changed through bitwise XORed operation via random matrix. For the sake of higher security, the initial conditions of chaotic maps are made dependent on the plaintext image and the parameters are computed via SHA-512. Furthermore, to decrease the transmission bandwidth, the measurement matrix is generated via Beta chaotic map. Instead of sending the whole measurement matrix, the sender will just send the Beta chaotic map initial conditions and control parameters (key) values along with the compressed ciphertext. The reliability and robustness of the designed image compression and encryption scheme are verified via experimental analysis and simulation results. All the experimental and simulation results are in favor of the proposed scheme.

Chaotic image encryption algorithm based on arithmetic sequence scrambling model and DNA encoding operation

In this paper, in order to solve the problem of un-rigorous scrambling method and single diffusion method in image encryption, a new method based on arithmetic sequence scrambling model, DNA coding sequence and one-dimensional Logistic mapping is proposed. First, the Hash array is obtained by combining the information of the original plaintext image with the Hash algorithm SHA-512. The Hash array generates the initial value and control parameters of the chaotic system, and then generates the chaotic key flow. Second, the arithmetic progression of partitioned matrix after scrambling, change the position of the original image pixels, replacement and operation, and then for DNA combines images and the chaotic sequence of chaotic system to produce DNA, DNA encoding, decoding rules for operation, change the original data bits of pixel values, thus further destruction of the original information. Finally, a chaotic diffusion operation is performed to further change the pixel information of the original image and output the cipher-text image. The experimental results and various security analyses show that the algorithm has good encryption effect and can resist the common plaintext attack, clipping attack and noise attack. The algorithm can be used for image encryption.

Chaos‐Based Engineering Applications with a 6D Memristive Multistable Hyperchaotic System and a 2D SF‐SIMM Hyperchaotic Map

In recent years, the research of chaos theory has developed from simple cognition and analysis to practical engineering application. In particular, hyperchaotic systems with more complex and changeable chaotic characteristics are more sensitive and unpredictable, so they are widely used in more fields. In this paper, two important engineering applications based on hyperchaos pseudorandom number generator (PRNG) and image encryption are studied. Firstly, the coupling 6D memristive hyperchaotic system and a 2D SF‐SIMM discrete hyperchaotic mapping are used as the double entropy source structure. The double entropy source structure can realize a new PRNG that meets the security requirements, which can pass the NIST statistical test when the XOR postprocessing method is used. Secondly, based on the double entropy source structure, a new image encryption algorithm is proposed. The algorithm uses the diffusion‐scrambling‐diffusion encryption scheme to realize the conversion from the original plaintext image to the ciphertext image. Finally, we analyze the security of the proposed PRNG and image encryption mechanism, respectively. The results show that the proposed PRNG has good statistical output characteristics and the proposed image encryption scheme has high security, so they can be effectively applied in the field of information security and encryption system.

An Improved Reversible Data Hiding in Encrypted Images Using Parametric Binary Tree Labeling

This work proposes an improved reversible data hiding scheme in encrypted images using parametric binary tree labeling(IPBTL-RDHEI), which takes advantage of the spatial correlation in the entire original image but not in small image blocks to reserve room for hiding data. Then the original image is encrypted with an encryption key and the parametric binary tree is used to label encrypted pixels into two different categories. Finally, one of the two categories of encrypted pixels can embed secret information by bit replacement. According to the experimental results, compared with several state-of-the-art methods, the proposed IPBTL-RDHEI method achieves higher embedding rate and outperforms the competitors. Due to the reversibility of IPBTL-RDHEI, the original plaintext image and the secret information can be restored and extracted losslessly and separately.

Cryptanalysis and Improvement in a Plaintext-Related Image Encryption Scheme Based on Hyper Chaos

Recently, a plaintext-related image encryption scheme based on a hyper-chaotic system has been proposed by Li et al . In their encryption scheme, the permutation process is related to the sum of plaintext pixel values, and the diffusion process is related to the values of nine special positions in the permuted image. This can resist the existing chosen plaintext attack due to the ever-changing permutation matrix and diffusion matrix when the plaintext is changed. Here, we show that Li’s encryption scheme contains two vulnerabilities. First, the gray values of the nine specific pixels do not change during diffusion. Second, the permutation process is reversible. Therefore, the diffusion process can be attacked and the permuted image can be obtained by constructing a special image, where the nine special position values in the special image’s permuted image are the same as those in the cipher image. Then, if the obtained permuted image is chosen as plaintext, we can get its permuted image by attacking the diffusion process. Since the permutation process is reversible, the permuted image is the original plaintext image. In addition, some improvements for Li’s encryption scheme are provided to enhance the security.

Lossless and Reversible Data Hiding in Encrypted Images With Public-Key Cryptography

This paper proposes lossless, reversible, and combined data hiding schemes for ciphertext images encrypted by public-key cryptosystems with probabilistic and homomorphic properties. In the lossless scheme, the ciphertext pixels are replaced with new values to embed the additional data into several least significant bit planes of ciphertext pixels by multilayer wet paper coding. Then, the embedded data can be directly extracted from the encrypted domain, and the data-embedding operation does not affect the decryption of original plaintext image. In the reversible scheme, a preprocessing is employed to shrink the image histogram before image encryption, so that the modification on encrypted images for data embedding will not cause any pixel oversaturation in plaintext domain. Although a slight distortion is introduced, the embedded data can be extracted and the original image can be recovered from the directly decrypted image. Due to the compatibility between the lossless and reversible schemes, the data-embedding operations in the two manners can be simultaneously performed in an encrypted image. With the combined technique, a receiver may extract a part of embedded data before decryption, and extract another part of embedded data and recover the original plaintext image after decryption.

LOSSLESS AND REVERSIBLE DATA HIDING IN ENCRYPTED IMAGES WITH PUBLIC KEY CRYPTOGRAPHY

A lossless, reversible, and combined data hiding schemes for ciphertext images encrypted by public key cryptosystems with probabilistic and homomorphic properties is proposed. In the lossless scheme, the ciphertext pixels are replaced with new values to embed the additional data into several LSB-planes of ciphertext pixels by multi-layer wet paper coding. Then, the embedded data can be directly extracted from the encrypted domain, and the data embedding operation does not affect the decryption of original plaintext image. In the reversible scheme, a preprocessing is employed to shrink the image histogram before image encryption, so that the modification on encrypted images for data embedding will not cause any pixel oversaturation in plaintext domain. Although a slight distortion is introduced, the embedded data can be extracted and the original image can be recovered from the directly decrypted image. Due to the compatibility between the lossless and reversible schemes, the data embedding operations in the two manners can be simultaneously performed in an encrypted image. With the combined technique, a receiver may extract a part of embedded data before decryption, and extract another part of embedded data and recover the original plaintext image after decryption.

LOSSLESS AND REVERSIBLE DATA HIDING IN ENCRYPTED IMAGES WITH PUBLIC KEY CRYPTOGRAPHY

In this paper, system uses the cryptography and steganography concept, which proposes a lossless, reversible, and combined data hiding methods for images encrypted by public key cryptosystems with probabilistic and homomorphic properties. In the lossless method, pixels of encrypted images are replaced with new values to embed additional data into LSB-planes of ciphertext pixels by multiple layer wet paper coding. Thus, original data can be directly extracted from encrypted image, and the data embedding does not affect the decryption of plaintext image. In the reversible method, histogram shrink is done before image encryption, so that the modification on cipher text images for data embedding will not cause any loss in plaintext image. With the combined lossless and reversible technique, receivers extract a part of embedded data before decryption, extract another part of embedded data and recover the original plaintext image after decryption. Keywords: Lossless, reversible, encryption, data hiding, decryption Cite this Article Amrtha Anand K, Dheena Kurien . Lossless and Reversible Data Hiding in Encrypted Images with Public Key Cryptography . Current Trends in Information Technology . 2016; 6(2): 27–33p.

A New Image Encryption Scheme Based on Dynamic S-Boxes and Chaotic Maps

Substitution box is a unique and nonlinear core component of block ciphers. A better designing technique of substitution box can boost up the quality of ciphertexts. In this paper, a new encryption method based on dynamic substitution boxes is proposed via using two chaotic maps. To break the correlation in an original image, pixels values of the original plaintext image are permuted row- and column-wise through random sequences. The aforementioned random sequences are generated by 2-D Burgers chaotic map. For the generation of dynamic substitution boxes, Logistic chaotic map is employed. In the process of diffusion, the permuted image is divided into blocks and each block is substituted via different dynamic substitution boxes. In contrast to conventional encryption schemes, the proposed scheme does not undergo the fixed block cipher and hence the security level can be enhanced. Extensive security analysis including histogram test is applied on the proposed image encryption technique. All experimental results reveal that the proposed scheme has a high level of security and robustness for transmission of digital images on insecure communication channels.

IARJSET - Science, Engineering and Technology

The following paper proposes a novel scheme of data hiding in encrypted images based on lossless compression of encrypted data. In encryption phase, the original content is encrypted into images. As majority of the encrypted data is kept unchanged, the quality of the decrypted image is satisfactory. In the receiver phase, the data is successfully extracted from the image with the help of a public key. The receiver can further recover the original plaintext image without any error.

Efficient reversible data hiding in encrypted images

This paper proposes a novel scheme of reversible data hiding in encrypted images based on lossless compression of encrypted data. In encryption phase, a stream cipher is used to mask the original content. Then, a data hider compresses a part of encrypted data in the cipher-text image using LDPC code, and inserts the compressed data as well as the additional data into the part of encrypted data itself using efficient embedding method. Since the majority of encrypted data are kept unchanged, the quality of directly decrypted image is satisfactory. A receiver with the data-hiding key can successfully extract the additional data and the compressed data. By exploiting the compressed data and the side information provided by the unchanged data, the receiver can further recover the original plaintext image without any error. Experimental result shows that the proposed scheme significantly outperforms the previous approaches.