Chaos-based Encryption Scheme Research Articles

A lightweight chaos-based encryption scheme for IoT healthcare systems

The Internet of Things (IoT) has transformed the healthcare industry by enabling new services and capabilities through connected devices and sensors. These devices, such as smartwatches and fitness tracker bands, can monitor various health metrics such as heart rate, blood pressure, and sleep quality. However, the security of these systems is a critical concern, as the unauthorized disclosure or access of healthcare information could have serious consequences for patients. This information can include personal and medical data, diagnostic and treatment information, as well as private locations. Lightweight encryption schemes are commonly used in IoT systems to protect this sensitive data. These schemes are designed to be fast and efficient, allowing them to encrypt and decrypt data in real-time, which is important for systems with limited computing power or storage capacity. In the last decade, there has been a significant increase in research and development in chaos cryptography. Due to chaotic systems’ unpredictable and sensitive nature, they can provide robust cryptographic schemes for data transmission between embedded devices. This makes it difficult for attackers to intercept and manipulate the data. Therefore, this work proposes a chaos-based lightweight encryption scheme for IoT healthcare systems with a primary application in the encryption of wearable devices. The proposed encryption scheme is based on a 2D 4-scroll chaotic attractor system, uniquely characterized for this work. The scheme is tested on an ARM-based microcontroller for encrypting PPG (Photoplethysmogram) biosignal data. The obtained results show that the chaos-based lightweight encryption scheme effectively improves the security of healthcare IoT systems while maintaining the real-time flow of data.

A novel pixel-split image encryption scheme based on 2D Salomon map

Images serve as a valuable information carrier for their properties of visualization and holding a large amount of messages. This paper presents a novel chaos-based encryption scheme to protect images from being captured or attacked. Firstly a two-dimensional Salomon map inspired by the Salomon function is proposed and there is a comprehensive comparison with other recent counterparts to validate the effectiveness of this chaotic system. Compared with traditional maps, the results show that 2D Salomon map has larger Lyapunov exponent, Kolmogorov entropy, Correlation dimension and Sample entropy. Especially the values of Lyapunov exponent can reach 11, which indicates that the chaotic sequence generated by Salomon map has strong randomness. Then a pixel-split image encryption scheme supported by 2D Salomom map is presented, itselectively exchanges the high and low bits of the image and globally spreads the altered pixels to random positions, resulting in that the cipher image contains no useful information any more and can only be recovered with a unique key. Ultimately, we have conducted comprehensive tests on the proposed algorithm, including various simulated attack, randomness tests and decorrelation analysis on cipher images, the overall results show that the scheme has excellent cryptographic effect and security.

A Robust Non-Blind Watermarking for Biomedical Images Based on Chaos

The advent of the Internet in these last years encouraged a considerable traffic of digital images. In the sanitary field, precisely in telemedicine branch, medical images play a very important role for therapeutic diagnoses. Thus, it is necessary to protect medical images data before transmission over the network to preserve their security and prevent unauthorized access. In this paper, a secure algorithm for biomedical images encryption scheme based on the combination of watermarking technique and chaotic function is proposed. In the proposed method, to achieve high security level performances, a non-blind hybrid watermarking technique with audio signal, Discrete Wavelet Transform is used; smoothness is also used as selected criteria; the iterations obtained by the chaotic sequences are essential and allow a good realization of the encryption process. One of the main advantages of chaos-based encryption schemes is the generation of a large number of key spaces to resist brute force attacks from the encryption algorithm. The experimental results presented in this paper attest to the invisibility and robustness of the proposed algorithm combining watermarking and chaos-based encryption.

A novel secure communications scheme based on chaotic modulation, recursive encryption and chaotic masking

The aim of this paper is to propose a new secure communications approach, obtained by combining into one scheme chaotic modulation, recursive encryption and chaotic masking. The objective is achieved by designing control laws to synchronize two hyperchaotic Lorenz systems with encrypted states via a backstepping technique. The encryption process relies on a Unified chaotic system, driven by the hyperchaotic Lorenz system, as well as on a recursive encryption algorithm that exploits an n-fold composition of an invertible function. A novel theorem is proved, which assures that the transmitted message is recovered at the receiver side by virtue of the synchronization of the two Lorenz systems via backstepping design. Numerical simulations are carried out using image and text as transmitted signals, with the aim to show the effectiveness of the conceived chaos-based encryption scheme.

Prediction Algorithm of Key Design Parameters for Space Chaotic Optical Communication System

Space laser optical communication has been widely investigated to achieve high bit rate information transmission. To enhance the information transmission security in space laser optical communication, chaos-based encryption scheme is adopted. It involves many parameters in designing a space chaotic optical communication system, which a proper tuning of them brings good communication performance. To investigate the key design parameters including the masking efficiency, transmitting optical power and mismatch coefficient, we give the calculation model of the bit error ratio (BER) based on traditional space laser optical communication system from the perspective of the authorized receiver and eavesdropper. Numerical results indicate that the BER for the eavesdropper is sensitive to the masking efficiency but not to the transmitting optical power. By contrast, the transmitting optical power plays a crucial role in the computational formula of the BER for the authorized receiver. A saturate optical power is also proposed at last which helps save the energy. These simulation results can be reference for practical system design.

A Novel Hybrid Secure Image Encryption Based on Julia Set of Fractals and 3D Lorenz Chaotic Map.

Chaos-based encryption schemes have attracted many researchers around the world in the digital image security domain. Digital images can be secured using existing chaotic maps, multiple chaotic maps, and several other hybrid dynamic systems that enhance the non-linearity of digital images. The combined property of confusion and diffusion was introduced by Claude Shannon which can be employed for digital image security. In this paper, we proposed a novel system that is computationally less expensive and provided a higher level of security. The system is based on a shuffling process with fractals key along with three-dimensional Lorenz chaotic map. The shuffling process added the confusion property and the pixels of the standard image is shuffled. Three-dimensional Lorenz chaotic map is used for a diffusion process which distorted all pixels of the image. In the statistical security test, means square error (MSE) evaluated error value was greater than the average value of 10000 for all standard images. The value of peak signal to noise (PSNR) was 7.69(dB) for the test image. Moreover, the calculated correlation coefficient values for each direction of the encrypted images was less than zero with a number of pixel change rate (NPCR) higher than 99%. During the security test, the entropy values were more than 7.9 for each grey channel which is almost equal to the ideal value of 8 for an 8-bit system. Numerous security tests and low computational complexity tests validate the security, robustness, and real-time implementation of the presented scheme.

Adaptive chaotic maps and their application to pseudo-random numbers generation

Abstract Chaos-based stream ciphers form a prospective class of data encryption techniques. Usually, in chaos-based encryption schemes, the pseudo-random generators based on chaotic maps are used as a source of randomness. Despite the variety of proposed algorithms, nearly all of them possess many shortcomings. While sequences generated from single-parameter chaotic maps can be easily compromised using the phase space reconstruction method, the employment of multi-parametric maps requires a thorough analysis of the parameter space to establish the areas of chaotic behavior. This complicates the determination of the possible keys for the encryption scheme. Another problem is the degradation of chaotic dynamics in the implementation of the digital chaos generator with finite precision. To avoid the appearance of quasi-chaotic regimes, additional perturbations are usually introduced into the chaotic maps, making the generation scheme more complex and influencing the oscillations regime. In this study, we propose a novel technique utilizing the chaotic maps with adaptive symmetry to create chaos-based encryption schemes with larger parameter space. We compare pseudo-random generators based on the traditional Zaslavsky map and the new adaptive Zaslavsky web map through multi-parametric bifurcation analysis and investigate the parameter spaces of the maps. We explicitly show that pseudo-random sequences generated by the adaptive Zaslavsky map are random, have a weak correlation and possess a larger parameter space. We also present the technique of increasing the period of the chaotic sequence based on the variability of the symmetry coefficient. The speed analysis shows that the proposed encryption algorithm possesses a high encryption speed, being compatible with the best solutions in a field. The obtained results can improve the chaos-based cryptography and inspire further studies of chaotic maps as well as the synthesis of novel discrete models with desirable statistical properties.

Designing a fast image encryption scheme using fractal function and 3D Henon Map

The sensitivity of the chaos-based encryption scheme towards the initial constraints, ergodic, unpredictability characteristics has gained maximum popularity in recent decade. In this paper, a Fast Chaos-based Image Encryption Scheme using Fractal and 3D Henon Maps (FCIES-Fr-HP) is proposed for improving the degree of security in the image transmission. This is attained by integrating the merits of the predominant fractal function with the indispensable features of Henon Maps to generate effective key stream which is essential for a reliable cryptosystem. In the proposed FCIES-Fr-HP scheme, the fractal function-based image encryption enhances the probability of preventing the cryptosystem from the brute-force attack. This improvement of fractal function is facilitated by improving the key space to the maximum order in hundreds of bits. Further, the trajectory mapping characteristics of the utilized 3D Henon Maps improves the ergodic characteristic and enforces superior unpredictability during the process of encryption. The advantages of complex XOR and chaotic circular pixel shuffling process (CCPSP) are incorporated in the proposed FCIES-Fr-HP scheme for enhancing the quality of the encryption process to a maximum extent. The experimental results of the proposed FCIES-Fr-HP scheme is investigated using differential analysis, statistical analysis and key space analysis confirmed a superior security level in the protection of the image under network transmission.

Design of a chaos-based encryption scheme for sensor data using a novel logarithmic chaotic map

This paper introduces a novel Logarithmic Chaotic Map (LCM) that is inspired by the well known quadratic map. The chaotic dynamic of the proposed map LCM is thoroughly investigated and its chaotic properties are found to be superior in comparison with the existing maps in the literature. In addition, a new encryption algorithm is proposed that is based on LCM. The chaotic output generated from LCM passed through all 15 National Institute of Standards and Technology (NIST) statistical tests thus confirming its randomness. The proposed encryption algorithm is best suited for encrypting numeric sensor data values preferably for IoT applications and has been found to be highly resilient to security attacks.

Three Techniques for Enhancing Chaos-Based Joint Compression and Encryption Schemes.

In this work, three techniques for enhancing various chaos-based joint compression and encryption (JCAE) schemes are proposed. They respectively improved the execution time, compression ratio, and estimation accuracy of three different chaos-based JCAE schemes. The first uses auxiliary data structures to significantly accelerate an existing chaos-based JCAE scheme. The second solves the problem of huge multidimensional lookup table overheads by sieving out a small number of important sub-tables. The third increases the accuracy of frequency distribution estimations, used for compressing streaming data, by weighting symbols in the plaintext stream according to their positions in the stream. Finally, two modified JCAE schemes leveraging the above three techniques are obtained, one applicable to static files and the other working for streaming data. Experimental results show that the proposed schemes do run faster and generate smaller files than existing JCAE schemes, which verified the effectiveness of the three newly proposed techniques.

An Image Encryption Scheme Based on Hybrid Electro-Optic Chaotic Sources and Compressive Sensing

In this paper, a novel image encryption scheme based on analog-digital hybrid electro-optic chaotic sources and compressive sensing is proposed. Distinguished from other existing chaos-based encryption schemes, analog-digital hybrid electro-optic chaotic sources are utilized, in which the synchronization of chaotic systems can be achieved by transmitting binary digital bits. The robustness of the encryption scheme can be significantly improved and the theoretical transmission distance will be much longer because of digital chaos synchronization. Moreover, owing to the compression of compressive sensing and the sensitivity to initial values of chaotic sources, the proposed scheme can greatly reduce the amount of data and strengthen safety. Exhaustive simulations and analysis demonstrate that the proposed scheme is of good peculiarities such as high efficiency, good robustness and security.

Novel Medical Image Encryption Scheme Based on Chaos and DNA Encoding

In this paper, we propose a new chaos-based encryption scheme for medical images. It is based on a combination of chaos and DNA computing under the scenario of two encryption rounds, preceded by a key generation layer, and follows the permutation-substitution-diffusion structure. The SHA-256 hash function alongside the initial secret keys is employed to produce the secret keys of the chaotic systems. Each round of the proposed algorithm involves six steps, i.e., block-based permutation, pixel-based substitution, DNA encoding, bit-level substitution (i.e., DNA complementing), DNA decoding, and bit-level diffusion. A thorough search of the relevant literature yielded only this time the pixel-based substitution and the bit-level substitution are used in cascade for image encryption. The key-streams in the bit-level substitution are based on the logistic-Chebyshev map, while the sine-Chebyshev map allows producing the key-streams in the bit-level diffusion. The final encrypted image is obtained by repeating once the previous steps using new secret keys. Security analyses and computer simulations both confirm that the proposed scheme is robust enough against all kinds of attacks. Its low complexity indicates its high potential for real-time and secure image applications.

A Selective Image Encryption Scheme Based on 2D DWT, Henon Map and 4D Qi Hyper-Chaos

In recent years hyperchaos has found applications in several fields such as medicine and engineering. It has been applied in image-based applications which require reliable, fast, and robust security systems to store or/and transfer images. Given the increased use of images, there is a fundamental requirement among security in ensuring protection, confidentiality, privacy, integrity, and authenticity of such images. This, in essence, has become a major concern. Many preventive and protective algorithms, including chaos-based schemes, have been developed over the past years in trying to prevent directed attacks. However, many existing chaos-based encryption schemes have been successfully decrypted. One of the main reasons for these chaos-based image encryption schemes being successfully attacked is that the degree of randomness of the chaotic system used is not high enough to guarantee robust encryption. The key space lengths of many of the existing cryptosystems are not long enough to guarantee the desired security properties of chaos-based ciphers. Thus, the security level is lowered. In this paper, a selective image encryption algorithm based on 2D Discrete Wavelet Transform, Henon's Map and 4D Qi Hyper Chaos is proposed. This paper is developed such that 2D DWT is used to decompose the image into details and approximations, Henon chaotic map is used to shuffle the decomposed image pixels' positions. The shuffled image is further encrypted with the bit streams generated by Qi hyperchaos using XOR operation. The experimental results demonstrate that the proposed algorithm provides a large key space, high security, and resistance to different types of attacks. When compared to some existing algorithms, the performance of the proposed method displays a better performance with respect to security and encryption making it suited for real-time applications.

Depreciating Motivation and Empirical Security Analysis of Chaos-Based Image and Video Encryption

Over the past years, an enormous variety of different chaos-based image and video encryption algorithms have been proposed and published. While any algorithm published undergoes some more or less strict experimental security analysis, many of those schemes are being broken in subsequent publications. In this paper, we show that two main motivations for preferring chaos-based image encryption over classical strong cryptographic encryption, namely computational effort and security benefits, are highly questionable. We demonstrate that several statistical tests, commonly used to assess the security of chaos-based encryption schemes, are insufficient metrics for security analysis. We do this experimentally by constructing obviously insecure encryption schemes and demonstrating that they perform well and/or pass several of these tests. In conclusion, these tests can only give a necessary, but by no means a sufficient condition for security. As a consequence of this paper, several security analyses in related work are questionable; further, methodologies for the security assessment for chaos-based encryption schemes need to be entirely reconsidered.

A Novel Image Encryption Scheme Based on Clifford Attractor and Noisy Logistic Map for Secure Transferring Images in Navy

Cryptography is a science to maintain the security of the message by changing data or information into a different form, so the message cannot be recognized. Today, many algorithms have been proposed for image encryption, but the chaotic encryption methods have a good combination of speed and high security. In recent years, the chaos based cryptographic algorithms have suggested some new and efficient ways to develop secure image encryption techniques. The chaos-based encryption schemes are composed of two steps: chaotic confusion and pixel diffusion. In the chaotic confusion stage, a combination of the chaotic maps is used to realize the confusion of all pixels.In this paper, we first give a brief introduction into chaotic image encryption and then we investigate some important properties and behaviour of the logistic map. The logistic map, aperiodic trajectory, or random-like fluctuation, could not be obtained with some choice of initial condition. Therefore, a noisy logistic map with an additive system noise is introduced. The proposed scheme is based on the extended map of the Clifford strange attractor, where each dimension has a specific role in the encryption process. Two dimensions are used for pixel permutation and the third dimension is used for pixel diffusion. In order to optimize the Clifford encryption system we increase the space key by using the noisy logistic map and a novel encryption scheme based on the Clifford attractor and the noisy logistic map for secure transfer images is proposed. This algorithm consists of two parts: the noisy logistic map shuffle of the pixel position and the pixel value. We use times for shuffling the pixel position and value then we generate the new pixel position and value by the Clifford system. To illustrate the efficiency of the proposed scheme, various types of security analysis are tested. It can be concluded that the proposed image encryption system is a suitable choice for practical applications.

A Key Space Enhanced Chaotic Encryption Scheme for Physical Layer Security in OFDM-PON

In this paper, we propose a key space enhanced chaos-based encryption scheme with no requirement of redundant sideband information in an orthogonal frequency division multiplexing passive optical network (OFDM-PON). For the first time, a simple 1-D chaotic logistic map is employed to scramble the chaotic subcarrier allocation both in time/frequency domain and logical operation, which provides a huge key space to enhance the physical layer confidentiality. Due to the dynamic chaotic permutations, the largest key space is achieved in comparison with the reported encryption schemes in OFDM-PON. In addition, a ∼10-Gb/s secure transmission with encrypted OFDM data is experimentally demonstrated over 25-km standard single-mode fiber. The proposed encryption scheme demonstrates the excellent security of data transmission in OFDM-PON and the robustness against exhaustive attacks.

Batch Image Encryption Using Generated Deep Features Based on Stacked Autoencoder Network

Chaos‐based algorithms have been widely adopted to encrypt images. But previous chaos‐based encryption schemes are not secure enough for batch image encryption, for images are usually encrypted using a single sequence. Once an encrypted image is cracked, all the others will be vulnerable. In this paper, we proposed a batch image encryption scheme into which a stacked autoencoder (SAE) network was introduced to generate two chaotic matrices; then one set is used to produce a total shuffling matrix to shuffle the pixel positions on each plain image, and another produces a series of independent sequences of which each is used to confuse the relationship between the permutated image and the encrypted image. The scheme is efficient because of the advantages of parallel computing of SAE, which leads to a significant reduction in the run‐time complexity; in addition, the hybrid application of shuffling and confusing enhances the encryption effect. To evaluate the efficiency of our scheme, we compared it with the prevalent “logistic map,” and outperformance was achieved in running time estimation. The experimental results and analysis show that our scheme has good encryption effect and is able to resist brute‐force attack, statistical attack, and differential attack.

A 2D CHAOS-BASED VISUAL ENCRYPTION SCHEME FOR CLINICAL EEG SIGNALS

In this paper, we have developed a two-dimensional (2D) chaos-based encryption scheme that can be applied to signals with transmission bit errors in clinical electroencephalography (EEG) and mobile telemedicine. As opposed to one-dimensional (1D) chaos-based encryption, the proposed 2D schemes uses the concept of parallel processing to increase the encryption speed. An essential feature of the proposed scheme is that signals mapping of a 2D chaotic scrambler and a permutation scheme are used to obtain clinical EEG information that requires high-level encryption. Simulation results show that when the correct deciphering parameters are inputted, EEG signals with a transmission bit error rate (BER) of 10 -7 are completely recovered. However, these signals can not be recovered if there is an error in the input parameters, for example, an initial point error of 0.00000001%.

New chaos-based encryption scheme for digital sequence

To enhance the anti-breaking performance of privacy information, this article proposes a new encryption method utilizing the leaping peculiarity of the periodic orbits of chaos systems. This method maps the secret sequence to several chaos periodic orbits, and a short sequence obtained by evolving the system parameters of the periodic orbits in another nonlinear system will be the key to reconstruct these periodic orbits. In the decryption end, the shadowing method of chaos trajectory based on the modified Newton-Raphson algorithm is adopted to restore these system parameters. Through deciding which orbit each pair coordinate falls on, the original digital sequence can be decrypted.

Application of periodic orbit theory in chaos-based security analysis

Chaos-based encryption schemes have been studied extensively, while the security analysis methods for them are still problems to be resolved. Based on the periodic orbit theory, this paper proposes a novel security analysis method. The periodic orbits theory indicates that the fundamental frequency of the spiraling orbits is the natural frequency of associated linearized system, which is decided by the parameters of the chaotic system. Thus, it is possible to recover the plaintext of secure communication systems based on chaotic shift keying by getting the average time on the spiraling orbits. Analysis and simulation results show that the security analysis method can break chaos shift keying secure communication systems, which use the parameters as keys.