A Modified Advanced Encryption Standard for Color Images

The present scenario of the medical field is that sending the healthcare images through the internet is so far exposed to security threats. Hence, there is a need for an efficient and secure procedure to exchange healthcare images over the Internet. The Digital Image and Communication in Medicine (DICOM) provides security features for image header information but not for the pixel information. Hence to send the pixel information in a highly secured manner, the pixels need to be encrypted by using a suitable encryption algorithm. The number of pixel changing rate (NPCR) and the unified averaged changed intensity (UACI) are well-known encryption evaluation metrics to analyse the differential attack in image encryption. These two values are used to calculate the average number of pixel changes and intensity changes between two encrypted images before and after modifying any one pixel in a plaintext image respectively. If these two values are high, then the image encryption can resist the differential attacks. In this paper, a theoretical value of NPCR and UACI are computed for DICOM image encryption concerning different significant levels. An encryption algorithm with Gould transform, RC5, logistic map and DNA Diffusion is proposed for DICOM image to increase the NPCR, and UACI value and this method offered an efficient security strategy for DICOM pixel information. Finally, the computed theoretical value of NPCR and UACI are compared with the existing and proposed algorithm.

This study introduces a cutting-edge image encryption algorithm aimed at elevating security standards. The Pan-Tompkins Algorithm (PTA) for key generation is proposed for the first time in this study. Additionally, employing steganography through the Least Significant Bit (LSB) method for embedding keys within the encrypted image enhances secure key distribution, thereby fortifying the encryption process. On the other hand, the integration of advanced algorithms, such as Zigzag scanning, the Affine Image Encryption Algorithm (AA), and the Vigenere Image Encryption Algorithm (VA), constitutes the fundamental innovation of the proposed image encryption algorithm. The proposed algorithm is named PanAAVA:Affine Algorithm and Vigenere Algorithm Encryption with PTA-Based Key Generation. The PanAAVA algorithm ensures unparalleled security by encrypting the positions and values of pixels using AA and VA. Notably, using PTA for key generation marks a distinctive and new key generation method feature of the algorithm. To assess the effectiveness of the PanAAVA, a comprehensive comparative analysis is conducted against well-established encryption methodologies, including Lena, Baboon, Airplane, and Pepper.The PanAAVA demonstrates exceptional proficiency in histogram analysis. The PanAAVA demonstrates a Unified Average Changing Intensity (UACI) of 33.4044%. Additionally, the Number of Pixels Change Rate (NPCR) is measured at 99.7442%, showcasing the algorithm’s effectiveness in inducing significant pixel changes. The proposed algorithm’s Mean Square Error (MSE) is calculated at 3.20679E5%. The proposed algorithm’s Peak Signal to Noise Ratio (PSNR) is recorded at 9.512475. The Key Space Size of the proposed algorithm is measured at 2209. Regarding correlation analysis, the PanAAVA achieves a high correlation score of 7.9996. The proposed algorithm successfully passes the National Institute of Standards and Technology (NIST) analysis, demonstrating a remarkably strong correlation close to 0 and a Structural Similarity Index Measure (SSIM) of 0.9977. Furthermore, regarding quantum communication, the proposed algorithm maintains stable key rates of 47.5 ± 0.8 kHz during the day and 50.9 ± 0.7 kHz at night. Additionally, PanAAVA achieves low Quantum Bit Error Rate (QBER) values of 4.77 ± 0.02, ensuring reliable and secure communication. The PanAAVA also demonstrates robust asymmetries at 49.81 ± 0.02 and 50.14 ± 0.03 for a crystal length of 20 mm. highlighting PanAAVA’s adaptability and effectiveness in different scenarios. PanAAVA outperforms other encryption algorithms concerning performance measurements and comparisons. In conclusion, the PanAAVA emerges as a beacon of superior security capabilities and innovation in image encryption, showcasing the potential to redefine standards in the field.

RC6 is considered one of the encryption strategies being utilized and modified to be suited for image protection. However, the RC6 encryption algorithm is still prone to statistical and differential attack which is one of the major concerns whenever open networks are to be used. In this paper, we proposed a modification of RC6 algorithm for image encryption. A new technique of permutation-diffusion architecture based on a modified concept of cyclic shift is integrated to increase the degree of permutation and diffusion mechanism of RC6 for image encryption. The security level, processing time and diffusion rate were tested using image evaluation metrics such as correlation coefficient test, number of pixel change rate (NPCR) test, unified average change intensity (UACI) test, and run-time analysis to measure its efficiency along with the simulation process. Results show that the proposed method illustrates a lower value of correlation among pixels and higher value of NPCR and UACI which makes the proposed method highly resistant to statistical and differential attacks. Increased security level with minimal time consumption is achieved in our approach.

The majority of imaging techniques use symmetric and asymmetric cryptography algorithms to encrypt digital media. Most of the research works contributed in the literature focus primarily on the Advanced Encryption Standard (AES) algorithm for encryption and decryption. This paper propose an analysis for performing image encryption and decryption by hybridization of Elliptic Curve Cryptography (ECC) with Hill Cipher (HC), ECC with Advanced Encryption Standard (AES) and ElGamal with Double Playfair Cipher (DPC). This analysis is based on the following parameters: (i) Encryption and decryption time, (ii) entropy of encrypted image, (iii) loss in intensity of the decrypted image, (iv) Peak Signal to Noise Ratio (PSNR), (v) Number of Pixels Change Rate (NPCR), and (vi) Unified Average Changing Intensity (UACI). The hybrid process involves the speed and ease of implementation from symmetric algorithms, as well as improved security from asymmetric algorithms. ECC and ElGamal cryptosystems provide asymmetric key cryptography, while HC, AES, and DPC are symmetric key algorithms. ECC with AES are perfect for remote or private communications with smaller image sizes based on the amount of time needed for encryption and decryption. The metric measurement with test cases finds that ECC and HC have a good overall solution for image encryption.

ABSTRACTRecently, in chaotic cryptography several new techniques have been suggested to develop efficient and secure image encryption algorithm for communication of image over insecure/public channels. Some of these techniques are computationally less complex but fails to provide sufficient security, and some techniques are though highly secured but increases computational overhead for encryption and decryption. This paper presents an efficient bit-plane encryption algorithm using chaotic, quadratic, and cubic maps. The proposed algorithm is based on the confusion, diffusion, and pixel randomisation processes. The encryption security of this technique for different bit-plane has been tested through key space analysis, statistical analysis, entropy analysis, and sensitivity analysis for real time image encryption and transmission. The presented algorithm shows the strength of security in terms of information entropy, peak signal-to-noise ratio (PSNR), number of pixels change rate (NPCR), unified average changing intensity (UACI), and correlation coefficient with the number of encrypted bit planes. It is clear that the strength of security increases with the number of encrypted bit planes, but the presented results demand that the level of security reached to the requirements (expected theoretically according to [C. Fu, et al., Optic Express, 20, 2363–78, Jan. 2012]) after encryption of four to six bit planes with reasonable small encryption/decryption time. This features proved the novelty of the proposed work. The algorithm is tested by the random and pseudo-random sequence of test standard SP 8000-22 released by National Institute of Standard and Technology Commission (NIST).

Secure image transmission is one of the most challenging problems in the age of communication technology. Millions of people use and transfer images for either personal or commercial purposes over the internet. One way of achieving secure image transmission over the network is encryption techniques that convert the original image into a non-understandable or scrambled form, called a cipher image, so that even if the attacker gets access to the cipher they would not be able to retrieve the original image. In this study, chaos-based image encryption and block cipher techniques are implemented and analyzed for image encryption. Arnold cat map in combination with a logistic map are used as native chaotic and hybrid chaotic approaches respectively whereas advanced encryption standard (AES) is used as a block cipher approach. The chaotic and AES methods are applied to encrypt images and are subjected to measures of different performance parameters such as peak signal to noise ratio (PSNR), number of pixels change rate (NPCR), unified average changing intensity (UACI), and histogram and computation time analysis to measure the strength of each algorithm. The results show that the hybrid chaotic map has better NPCR and UACI values which makes it more robust to differential attacks or chosen plain text attacks. The Arnold cat map is computationally efficient in comparison to the other two approaches. However, AES has a lower PSNR value (7.53 to 11.93) and has more variation between histograms of original and cipher images, thereby indicating that it is more resistant to statistical attacks than the other two approaches.

A wrist-based photoplethysmography (PPG) tool offers a simple and non-invasive approach for applications in vital sign monitoring and healthcare. However, in a telecare network, these physiological signals ensure the authorisation demands for the domain of medical applications. Hence, this study proposes an intelligent method for PPG signal encryption and decryption. This method combines chaotic map and radial basis function network (RBFN) into symmetric cryptography with an adaptive scheme. The sine-power chaotic map is used as a key generator of 256 non-ordered numbers (key space) to set the private cipher codes. Two RBFNs are used to train an encryptor and a decryptor with the authorised cipher codes. Its substitution-based infosecurity scheme can change the numerical values of PPG raw data for each encrypted communication, and the decrypted PPG data are further applied for time- and frequency-domain analyses in clinical applications, such as heart and respiration rate analysis and arterial stiffness and upper extremity vascular disease evaluations. Through experimental results, the security levels are validated using the number of pixel change rate (NPCR), unified averaged changed intensity (UACI), and correlation analysis. The average NPCR, UACI, and correlation coefficient (CC) are 96.57%, 35.43%, and 0.005, respectively, between the plain PPG and the encrypted PPG data against hacker attacks. The larger-the-better of NPCR and UACI indexes and the smaller-the-better of CC index are obtained to evaluate the efficiency of the proposed cryptography method. The encrypted PPG also guarantees physiological signals of good quality in clinical applications. In addition, the performance of RBFN-based method is superior in adaptive learning capability than that of the traditional learning method in real-time applications.

Nowadays, Satellite remote sensing and especially earth observation satellites require improvement when implementing an algorithm using reconfigurable hardware in terms of efficiency, performance, and security level. Furthermore, the transmission of the computed data from the earth observation satellite to the ground station is subject to potential attacks, and data can be corrupted during transmission. The land surface Temperature algorithm is an essential factor that can be extracted from the earth observation satellite. In this paper, we proposed a secure land surface temperature implementation by combining the advanced encryption algorithm and Hamming code implemented on radiation-tolerant Virtex-4QV field programmable gate array (FPGA). The iterative looping technique was used to implement the Advanced Encryption Standard (AES) algorithm with the aim of achieving high throughput and high security levels. The results showed that the proposed hardware implementation consumes 3319 Slices and 2 BRAMs while achieving higher throughput of 1854.82 Mbps. Moreover, we have evaluated the efficiency of the suggested cryptosystem by exploiting security measurement analysis such as Histogram, correlation coefficient, entropy, number of pixels change rate (NPCR), and unified averaged changed intensity (UACI). The proposed cryptosystem results prove the efficiency in terms of hardware consumed and high-security level. This implementation may be utilized, proposed, and even configurable for any earth observation satellites, including nano- and pico-CubeSats since we employed radiation-tolerant FPGA.

Medical images are regarded as important and sensitive data in the medical informatics systems. For transferring medical images over an insecure network, developing a secure encryption algorithm is necessary. Among the three main properties of security services (i.e., confidentiality, integrity, and availability), the confidentiality is the most essential feature for exchanging medical images among physicians. The Goldreich Goldwasser Halevi (GGH) algorithm can be a good choice for encrypting medical images as both the algorithm and sensitive data are represented by numeric matrices. Additionally, the GGH algorithm does not increase the size of the image and hence, its complexity will remain as simple as O(n2). However, one of the disadvantages of using the GGH algorithm is the Chosen Cipher Text attack. In our strategy, this shortcoming of GGH algorithm has been taken in to consideration and has been improved by applying the padding (i.e., snail tour XORing), before the GGH encryption process. For evaluating their performances, three measurement criteria are considered including (i) Number of Pixels Change Rate (NPCR), (ii) Unified Average Changing Intensity (UACI), and (iii) Avalanche effect. The results on three different sizes of images showed that padding GGH approach has improved UACI, NPCR, and Avalanche by almost 100%, 35%, and 45%, respectively, in comparison to the standard GGH algorithm. Also, the outcomes will make the padding GGH resist against the cipher text, the chosen cipher text, and the statistical attacks. Furthermore, increasing the avalanche effect of more than 50% is a promising achievement in comparison to the increased complexities of the proposed method in terms of encryption and decryption processes.

Differential evolution (DE) is a powerful evolutionary algorithms, widely applied in different fields of science and engineering for solving the problem of optimization. Since image encryption has been viewed as an interesting research topic by many experts and innumerable methods to encrypt images have emerged, currently, the focus is on obtaining optimized images. The paper presents a novel image encryption scheme that uses intertwining logistic map (ILM), DNA encoding and DE optimization. The proposed approach is based on three phases: permutation involving ILM, diffusion engaging DNA and optimization using DE. Parameters like entropy, key sensitivity, secret key space, unified average change in intensity (UACI), correlation coefficient —vertical, horizontal and diagonal, and number of pixel change rate have been evaluated to test the efficiency of the proposed method. The paper also compares this performance with that of the genetic algorithms (GA), used previously for optimization. The significance of this approach is enhancing entropy, the essential characteristic of randomness, resisting against numerous statistical and differential attacks and generating good experimental results. The main contribution of this paper is to present the efficiency of DE in image optimization and exhibit how DE is better than GA.

Security of image data is essential during communication from various security attacks. This paper proposed a new technique for RGB color image encryption and decryption by the combination of shuffling and masking. The chaotic Baker map is used for first layer of image encryption by randomizing the pixels of each components of color image such as red, green and blue and then applying the diffusion process i.e. fractional dual random phase masks (FDRPM) technique which is applied on each component to increase the security level of given method. The order of Discrete Fractional Fourier Transform (DFRFT) act as a key for the process which provides extra degree of security to the proposed system. Matlab simulations are performed to check the security robustness of proposed scheme. Performance of proposed scheme is verified by noise analysis such as mean square error (MSE) and various differential analysis such as Unified Average Change Intensity (UACI) and Number of Pixels Change Rate (NPCR). Results of various analysis shows that the novel proposed encryption technique shows high efficiency and security for color images.

The security of information and digital images has become a major issue during the last three decades. A large number of algorithms for data and image encryptions are reported in the literature. However, many of the proposed algorithms are not suitable in the fields of application, because they are cryptographically weak. In the present work, a novel algorithm for encoding digital images by using a circle map with 3 parameters has been proposed. In this article different images are used for testing the validity of the proposed algorithm. The algorithm has increased the strength of security of the image encryption against cipher-text-only, chosen-plaintext and chosen-cipher-text attacks. The analysis of cryptographic strength has also been performed to confirm the fact. The results of several experimental tests, such as, key space analysis, key sensitivity analysis and statistical analysis show that the proposed algorithm for image cryptosystems provides an efficient and secure way for image encryption. A comparison in terms of correlation between the initial and transformed images, number of pixels change rate (NPCR) and unified average changing intensity (UACI) is also done. Keywords: Circle map, Chaos, Lyapunov exponent, anti-differential attack, NPCR, UACI.

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.

Cancelable biometric techniques play a vital role in the privacy and security of remote surveillance systems to keep the genuine users’ confidential data safe and away from intruders. This research presents an efficient cancelable biometric framework by exploiting an irreversible hybrid encryption technique that incorporates Deoxyribonucleic, Ribonucleic acid sequences (DNA and RNA), and the evolutionary optimization technique of the Genetic Algorithm (GA). So, these techniques are employed to create completely deformed templates from their original ones. Thus, our main contribution is offering a novel biometric security framework that achieves unique randomness characteristics using RNA and DNA sequences and the evolutionary GA-based encryption scheme. The proposed framework produces an entirely unrecognized biometric template by ciphering the main discriminative features of the biometric traits of the authorized clients. The proposed algorithm is first initialized by creating several encrypted biometric images of the original users by employing the logistic map function. Secondly, the initialized encrypted images are transformed into one vector of a binary array. Then, they are converted to their corresponding introns, exons, and consequently, their relevant codons are stored in the cloud database. Thirdly, these relevant codons are replaced by new ones after generating encrypted RNA lists. The utilized encryption key is extracted from the original biometric image after utilizing excessive permutations between its pixels. Then, the GA-based optimization technique is applied to select the most convenient biometric features. Finally, after employing the GA-based cross-over and mutation operations, the chosen features are used to generate the cancelable biometric traits. To validate the security efficacy of the proposed framework, different six biometric databases are used, which are Olivetti Research Laboratory (ORL) Faces (gray), CASIA v.5 Faces (color), UPOL Iris (gray), Indian Institute of Technology Delhi (IIT Delhi) Ear (color and gray), Fingerprint, and CASIA Palmprint (color and gray). The security performance of the proposed framework is compared to those of recent studies in this field, such as OSH (Optical Scanning Holography) and DRPE (Double Random Phase Encoding). The simulation results prove the superior performance of the proposed framework in terms of all tested evaluation metrics. The proposed framework provides high AROC (Area under the Receiver Operating Characteristic) that reaches 0.9990, low FAR (False Acceptance Rate) of 0.0015, more uniform histograms, high correlation values for genuine users, and complete hidden of biometric features. In addition, from a security perspective, the proposed framework accomplishes good entropy, UACI (unified average changing intensity), and NPCR (number of pixels change rate) values that reach 7.9960, 33.55%, and 99.65%, respectively.

In this paper, a cryptosystem is proposed to encrypt 16-bit monochrome DICOM image using enhanced chaotic economic map. A new enhanced chaotic economic map (ECEM) is designed from the chaotic economic map which has better bifurcation nature and positive Lyapunov exponent values. In order to improve the sternness of the encryption algorithm, the enhanced chaotic map is employed to generate the pixel permutation, masking, and swapping sequences. The substitution operation is introduced in-between the standard permutation and diffusion operations. The robustness of the proposed image encryption algorithm is measured by various analyses such as histogram, key sensitivity, key space, number of pixel change rate (NPCR), unified average change intensity (UACI), information entropy and correlation coefficient. The results of the security analyses are compared with existing algorithms to validate that the proposed algorithm is better in terms of larger key space to resist brute force attacks and other common attacks on encryption.