Chaotic Key Research Articles

Message steganography using separate locations and blocks

A novel method of message steganography is introduced to solve the disadvantages of traditional least significant bit (LSB) based methods by dividing the covering-stego image into a secret number of blocks. A chaotic logistic map model was performed using the chaotic parameters and the number of image blocks for generating a chaotic key. This key was then sorted, and the locations of blocks 1 to 8 were used to select the required blocks to be used as covering-stego blocks. The introduced method simplifies the process of message bits hiding and extracting by adopting a batch method of bits hiding and extracting. A comparative analysis was conducted between the outcomes of proposed method and those of prevalent approaches to outline the enhancements in both speed and quality of message steganography.

MieWC: Medical image encryption using wavelet transform and multiple chaotic maps

AbstractRecently, digital images have been widely used in several applications through advanced wearable devices and networks. Despite several benefits of digital images, such as easy distribution, storage, and reproduction, it is difficult to prevent the issue of identity theft, privacy leakage, and ownership conflicts. We present a wavelet‐based encryption technique, MieWC, to solve the above issues using multiple chaotic keys. This work uses multiple keys for the encryption process, which ensures high security and authenticity. Lorenz and logistic maps are used for chaotic key generation for diffusion and confusion processes. Further, the technique is tested for two different wavelet transforms, including integer wavelet transform (IWT) and discrete wavelet transform, with IWT giving better results. Hence, it is being used for further analysis. The proposed technique is easy to implement and provides high security with improved results. It has low time complexity and high key bit sensitivity. The result analysis further ensures resistance against crop attacks.

Complex CLMM Private Keys to Secure Digital Color Images

Color digital images are one of the most widespread and widely used types of data, and the image can be secret or of a special nature, or it can be a carrier of confidential data, which makes protecting it very important. In this research, a new method for protecting color digital images will be presented, and the ease of implementing this method and its suitability for any digital image will be shown. The proposed method will provide a high degree of security and provide a high degree of protection for the digital image through the use of a complex private key based on chaotic logistic map model, six chaotic key will be used to form six integer keys, and these keys will be resized to match the dimensions of each color channel. The proposed method will use two rounds of data cryptography; each round will require three private keys, one for each color. Different variations of CLMM will be used to generate 1D and 2D chaotic keys, the results of using 1D chaotic keys will be compared with the results of using 2D chaotic keys and some recommendations will be raised. The proposed method will be implemented, different types of results analysis's (Quality analysis, sensitivity analysis, and throughput analysis) to improve the enhancement provided by yje proposed method comparing with other existing methods.

Improving the Use of Chaotic Keys in Message Cryptography

Using chaotic logistic keys in message cryptography is a popular technique; it provides a high level of message security by protecting it from being hacked. This technique becomes inefficient when the message length is big, because a chaotic key of big length requires much time to be generated. To overcome this problem this paper research will provide a novel method for short and long messages cryptography. The new method will use a complicated private key which will provide a huge key space to resist any kids of attacks. The private key will be used to divide the message into equal blocks (except the last block), and it will be also used to generate the index keys which are required to apply encryption and decryption, these keys will be generated from the obtained chaotic logistic keys. The proposed method will use a simple encryption and decryption functions, these functions will use the index keys values to distribute the source message to form the encrypted message and to retrieve the decrypted message from the encrypted one. A recommendation of message dividing into blocks will be suggested, depending on the message length: when to divide a message and how many blocks are required. The required number of message blocks will be tested for various in length messages, the throughputs will be calculated to justify the process of message dividing into blocks. The proposed method will tested using various short and long messages, the obtained results will be analyzed to prove the quality, security, sensitivity and the efficiency of the proposed method.

A New Sine-Ikeda Modulated Chaotic Key for Cybersecurity

In the recent past, the storage of images and data in the cloud has shown rapid growth due to the tremendous usage of multimedia applications. In this paper, a modulated version of the Ikeda map and key generation algorithm are proposed, which can be used as a chaotic key for securely storing images in the cloud. The distinctive feature of the proposed map is that it is hyperchaotic, highly sensitive to initial conditions, and depicts chaos over a wide range of control parameter variations. These properties prevent the attacker from detecting and extracting the keys easily. The key generation algorithm generates a set of sequences using a designed chaos map and uses the harmonic mean of the generated sequences as the seed key. Furthermore, the control parameters are modified after each iteration. This change in the control parameters after each iteration makes it difficult for an attacker to predict the key. The designed map was tested mathematically and through simulations. The performance evaluation of the map shows that it outperforms other chaotic maps in terms of its parameter space, Lyapunov exponent, bifurcation entropy. Comparing the designed chaotic map with existing chaotic maps in terms of average cycle length, maximum Lyapunov exponent, approximate entropy, and a number of iterations, it is found to be very effective. The existence of chaos is also proved mathematically using Schwartz’s derivative theorem. The proposed key generation algorithm was tested using the National Institute of Standards and Technology (NIST) randomness test with excellent results.

Blockchain based Certificate Validation

Certificate management is a tedious task for any university or any other organization. These schemes impose problems in Public Key Infrastructure (PKI). Checking the validity and preserving the security of these documents is of utmost importance. In this work, we have devised a blockchain-based solution for preventing malfunctioning in certificate validation which is an important step for any university. Each certificate is uploaded in its hash format and is stored using blockchain. The hashes are stored in unique transactions in nodes, which are deployed on a private network. Using the SHA-256 hashing algorithm, the certificates are uploaded into the system and can be viewed by anyone with the right credentials. Due to the usage of blockchain technology, the certificates are stored in a decentralized manner, which ensures there is no central point of failure. Any changes in the uploaded document need to be validated by other nodes. This paper also improvises that when certificate uploading is required new nodes are added, instead of modifying the past blocks. This work provides a very user-friendly app where any user with the right credentials can upload documents. In this work, digitized documents are stored using Inter Planetary File System (IPFS) which is distributed method of storage. Our theoretical analysis proves that it is a user-friendly application with the security of blockchain technology in partnership with IPFS. Only the issuer can upload documents and others can only view them. Using our proposed solution, problem of malicious certificates can be tackled with E-certification. The proposed method solves all the issues of storing, validating, and sharing documents. Chaotic Map technique is used in hash generation which is quite simple to implement. The proposed approach Chaotic Key based Certificate validation (CK-Cert) provides a hassle-free solution for certificate managements since it better manages the block size as compared to previously proposed techniques (PBCert and CertChain) as discussed with the help of graphs.

Image encryption based on Logistic-Sine self-embedding chaotic sequence

In this article, for the security of image transmission, we present a novel image encryption algorithm based on Logistic-Sine self-embedding (LSSE) chaotic sequence. Firstly, we verify the effectiveness and superiority of the chaotic map by using a variety of indicators such as the Lyapunov exponent, bifurcation diagram, and 0-1 test. The chaotic key is combined with Arnold scrambling transformation to scramble the image, to break the high correlation between image pixels. Then, the image is diffused based on LSSE. The robustness and effectiveness of the proposed method are verified by various computational tests, and the scheme is analyzed using the performance indicators of histogram distribution, correlation, key sensitivity, attack test, and comparison with other algorithms. The computational experiments show that the algorithm has excellent performance and adequate security.

Provable Chaotically Authenticated Encrypted Biomedical Image Using OFDM Transmission

In this research, a unique multiband random chaotic key generator based provable authenticated encrypted technique for biomedical picture for the healthcare biomedical system, which can be used in 5G communication system is presented. In addition, the encryption method employed in this research is based on Multiband Random Chaotic Key Generator, and the proposed provable authenticated methodology is based on symmetric authenticated encryption data (MBRCKG). In the proposed proven Orthogonal Frequency Division Multiplexing (OFDM) communication system, the Authenticated Chaotic Encrypted Biomedical Image (ACE-BI) is utilized. This study uses discrete wavelet transformation (DWT) and discrete cosine transformation (DCT) to mask patient data and hospital watermarks in biological images. With various statistical and OFDM settings, channel analysis and statistical analysis have been examined for their effects on the collected hospital logo and patient data. The simulation studies demonstrate how resistant to communication signal processing the proposed ACE-BI method is. Additionally, the proposed algorithm is able to reduce encryption time to one quarter because the partial encryption based in one level DWT scheme.

Dynamic fractional chaotic biometric isomorphic elliptic curve for partial image encryption

In this paper, a Modular Fractional Chaotic Sine Map (MFC-SM) has been introduced to achieve high Lyapunov exponent values and completely chaotic behavior of the bifurcation diagram for high level security. The proposed MFC-SM is compared with the conventional non MFC-SM and it has an excellent chaotic analysis. In addition, the randomness test results indicate that the proposed MFC-SM shows better performance and satisfy all randomness tests. Due to the excellent chaotic properties and good randomization results for the proposed MFC-SM, it is used to be cooperated with the biometric digital identity to achieve dynamic chaotic biometric digital identity. Also, for real time image encryption, both Discrete Wavelet Transform (DWT)partial image encryption and Isomorphic Elliptic Curve (IEC)key exchange are used. In addition, the biometric digital identity is extracted from the user fingerprint image as fingerprint minutia data incorporated with the proposed MFC-SM and hence, a new Dynamic Fractional Chaotic Biometric Digital IdentityIEC (DFC-BID-IEC) has been introduced. Dynamic Fractional Chaotic Key Generator (DFC-KG) is used to control the key schedule for all encryption and decryption processing. The encryption process consists of the confusion and diffusion steps. In the confusion step, the 2D Arnold Cat Map (ACM) is used with secret parameters taken from DFC-KG. Also, the diffusion step is based on the dynamic chaotic self-invertible secret key matrix which can be generated from the proposed MFC-SM. The IEC key exchange secret parameters are generated based on Elliptic Curve Diffie?Hellman(ECDH) key exchange and the isomorphism parametre. Statistical analysis, differential analysis and key sensitivity tests are performed to estimate the security strengths of the proposed DFC-BID-IEC system. The experimental results show that the proposed algorithm is robust against common signal processing attacks and provides a high security level and high speed for image encryption application.

Meaningful ciphertext encryption algorithm based on bit scrambling, discrete wavelet transform, and improved chaos

This paper proposes a meaningful ciphertext encryption algorithm of good practicability and strong robustness. The plaintext undergoes pre-encryption of bit scrambling and secondary encryption of discrete wavelet transform (DWT) to obtain meaningful ciphertext. In the pre-encryption stage, only the higher three bit pages that are not all 0 or 1 are scrambled. The embedding method in the secondary encryption process is to add the hundreds and tens’ digit and ones’ digit of the middle ciphertext to the scrambled detail information obtained by DWT of the cover image. The information entropy of the intermediate ciphertext obtained by this method can reach 7.997, the correlation coefficient between the ciphertext and the cover image can reach 0.99, and the decrypted image of the ciphertext under high-intensity pollution can still be identified. It shows that the pre-encryption can conceal the plaintext information well, and the secondary encryption can eliminate the ciphertext texture characteristics while retaining the good robustness. Finally, the improved three one-dimensional chaos are used to generate random sequences, and the plaintext hash value is associated with the chaotic key. The improved chaos greatly improves the randomness of the sequence and broadens the range of parameters. The hash value SHA-256 of the plaintext is added to make the key stream adaptively change with the plaintext, which greatly improves the sensitivity of the plaintext and the ability to resist selected plaintext and ciphertext attacks. Experiments have also verified that the encryption algorithm can encrypt images of different types and shapes and has strong practicability, good bit scrambling effect, and high sensitivity to scrambling.

Realization of an Analog Computing Circuit for Simulating a Chaotic Electro Optic System and Validation of Model using Lyapunov Exponent

Chaotic optical communication is attractive for its security because in such type of communication optical signal is encrypted using the optical chaos and decrypted at the receiver side with identical chaotic key. Chaotic signals are created using nonlinear optical systems with sensitive dependence in initial condition. In our work we have chosen an Electro Optic modulator based nonlinear optical system for producing optical chaos. However the optical devices are costly and not easily accessible. Hence to overcome this difficulty we have created a nonlinear analog computing circuit capable of producing chaotic signals as those of nonlinear Electro Optic or Acusto Optic system. Extensive numerical experiments have been conducted on this electronic system for studying its chaotic behaviour and it has been found that our electronic simulator is able to mimic the actual Electro Optic system up to a large extent.

Fractional chaos based-cryptosystem for generating encryption keys in Ad Hoc networks

Ad Hoc networks are considered essential elements of the Internet of Things (IoT), which is a technological trend for innovative future applications. Since in IoT systems the devices are mostly connected among them, the data exchange is a vital activity in the network. In this kind of networks, not only non-sensitive data exchange is performed, but also sensitive data (digital signatures, login credentials, account numbers, personal images, and so on) are shared. Therefore, new appropriate approaches to encrypt the secret information are highly required. This paper presents an experimental setup of a fractional-chaos based-cryptosystem for ad hoc networks under the IEEE 802.15.4 standard. The proposed cryptosystem is composed of a novel chaotic pairing approach between the coordinator node and end-devices nodes to sending data into the network. More specifically, the RF-data of the IEEE 802.15.4 frame is encrypted using a fractional-order encryption key and four iterative steps. It is worth to note that the chaotic key is based on a fractional-order chaotic system, which is derived from the fractional calculus theory. Fractional-order chaotic dynamics are demonstrated using the Lyapunov method and equilibria stability. Next, the experimental validation of the cryptosystem is shown sending an encrypted image between ARM digital platforms and wireless Xbee modules. Several security analyses indicate the proposed encryption scheme has suitable statistical properties, sizeable keyspace, and high sensitivity providing secure communications.

Chaos‐based physical‐layer encryption for OFDM‐based VLC schemes with robustness against known/chosen plaintext attacks

The technology of visible light communication (VLC) is regarded as an appealing technique for upcoming wireless indoor multimedia communications. Considering the broadcast aspect of visible light propagation, the visible light interface is exposed and approachable to both licensed and unlicensed parties settled within the illuminated region. In this study, the authors present a chaos-based physical-layer encryption method for orthogonal frequency division multiplexing (OFDM)-based VLC schemes with the ability to counter known-plaintext attacks (KPAs) and chosen-plaintext attacks (CPAs). A logistic map is utilised for the chaos mapping. The presented method produces dynamic ciphertexts by employing the random quality of the chaotic keys and input data. It uses a multiple-fold encryption protocol which implements chaotic scrambling of the subcarrier distribution in time and frequency domains, as well as chaotic polarity inversion of subcarriers. To generate the secret key, a chaotic key creation approach is introduced by including the position-sensitive and real-valued channel state information of the VLC channel. The presented method provides supreme confidentiality for the OFDM-based VLC schemes to counter KPAs, CPAs, brute-force attacks, and statistical attacks. The secrecy capacity of the presented method is improved by applying a pre-equalisation technique at the transmitter instead of the receiver.

Statistical Analysis and Security Evaluation of Chaotic RC5-CBC Symmetric Key Block Cipher Algorithm

In some previous research works, it has been theoretically proven that RC5-CBC encryption algorithm behaves as a Devaney topological chaos dynamical system. This unpre-dictable behavior has been experimentally illustrated through such sensitivity tests analyses encompassing the avalanche effect phenomenon evaluation. In this paper, which is an extension of our previous work, we aim to prove that RC5 algorithm can guarantee a much better level of security and randomness while behaving chaotically, namely when embedded with CBC mode of encryption. To do this, we have began by evaluating the quality of such images encrypted under chaotic RC5-CBC symmetric key encryption algorithm. Then, we have presented the synthesis results of an hardware architecture that implements this chaotic algorithm in FPGA circuits.

Elliptic Curve Video Encryption in Mobile Phone Based on Multi-Keys and Chaotic Map

The security of video applications in mobile devices has become recently an important field research. Dealing with video data, which is large compared to text and image and processing it in the mobile platform is a big challenge. Generally, the efficiency of any video encryption algorithm is concerned with two criteria, the computational time required to process video data, and the memory usage according to the resources on the smartphone. The secured system in 3G devices has become a matter of importance. This paper presents an implementation of full video encryption using Elliptic Curve Cryptography (ECC) on a mobile device. The operations on ECC include doubling and addition on the finite field as the backbone for an elliptic curve. Also, mapping representation is introduced to convert every byte of plain video into a point on EC. The paper proposed multi-keys instead of using one key as usual. Also, Chaotic Key Generator (CKG) is exploited for the randomness of the multi-keys. The proposed work focuses on increasing the security with multi-keys and to get acceptable time for encryption and decryption in a limited environment like mobile. The system is implemented using Android Studio with version (3.0) and using java language, it is implemented on Android version 7.0 (Nougat) and on mobile Galaxy S8.

Physical-Layer Security Against Known/Chosen Plaintext Attacks for OFDM-Based VLC System

This letter introduces a chaos-based physical-layer security approach for an orthogonal frequency division multiplexing (OFDM)-based visible light communication (VLC) system with the capability against known-plaintext attacks (KPAs) and chosen-plaintext attacks (CPAs). This approach generates dynamic cyphertexts by exploiting the random characteristics of chaotic keys and input data. It performs chaotic permutation of subcarrier allocation in time/frequency domains and chaotic polarity reversal of subcarriers. For secret-key generation, we present chaotic key generation protocol with the help of the position-sensitive and real-valued channel state information of the VLC channel. The results show that our approach supports superior confidentiality for OFDM-based VLC systems against KPAs and CPAs.

Cryptanalysis of a Chaotic Key Based Image Encryption Scheme

Security of multimedia data is a major concern due to its widespread transmission over various communication channels. Hence design and study of good image encryption schemes has become a major research topic. During the last few decades, there has been a increasing in chaos-based cryptography. This paper proposes an attack on a recently proposed chaos based image encryption scheme. The cryptosystem under study proceed by first shuffling the original image to disturb the arrangement of pixels by applying a chaotic map several times. Second, a keystream is generated using Chen's chaotic system to mix it with the shuffled pixels to finally obtain the cipher image. A chosen ciphertext attack can be done to recover the system without any knowledge of the key. It simply demands two pairs of plaintext-ciphertext to completely break the cryptosystem.

A discrete-time chaos synchronization system for electronic locking devices

This paper presents a novel electronic locking key based on discrete-time chaos synchronization. Two Chen chaos generators are synchronized using the Model-Matching Approach, from non-linear control theory, in order to perform the encryption/decryption of the signal to be transmitted. A model/transmitter system is designed, generating a key of chaotic pulses in discrete-time. A plant/receiver system uses the above mentioned key to unlock the mechanism. Two alternative schemes to transmit the private chaotic key are proposed. The first one utilizes two transmission channels. One channel is used to encrypt the chaotic key and the other is used to achieve output synchronization. The second alternative uses only one transmission channel for obtaining synchronization and encryption of the chaotic key. In both cases, the private chaotic key is encrypted again with chaos to solve secure communication-related problems. The results obtained via simulations contribute to enhance the electronic locking devices.

Image Merger Encryptor: A Chaotic and Chebyshev Key Approach

Image Merger Encryptor: A Chaotic and Chebyshev Key Approach

Image Security using ECC Approach

Objectives: The role of digital images are vast in todays trends and it is exposed to illicit access, modifications that must needs confidentiality during the stages of data archival and communication1, systems, wireless devices. In order to facilitate secret communication, image encryption have bring into being a significant place in both public and private services like as military supervision, health systems, financial services like online trading and video conferencing and so on. Some methods are proposed on the image encryption which they include the Paper2 have developed a method for A Chaotic Key Based Algorithm (CKBA) to change the pixel values of the plain-image. In 3 have developed a protocol for random combinational image encryption approach with bit, pixel and block permutations Paper4 proposed a technique to encrypt an image for secure transmission using the digital signature of the image. Methods: The proposed work is developed that provides secured authentication to integrate the image encryption with Elliptic Curve Cryptography to provide security. In this work, transformation operation of the matrix operations are performed on the original image matrix and the transformed image is further encrypted with the help of a key sequence which is generated from the elliptic Curve. The encrypted image will be authenticated using Elliptic Curve Diffie Helman (ECDH) key exchange algorithm5 and finally decrypted by using the key generated from the chosen elliptic curve and then we perform the reverse transformations on the matrix obtained . So after decryption process to acquire the original image. Findings: In this work we can get better security to image ecryption by application of ECC with matrix operations performed on image data. Because ECC has the well attention of researchers and robust mathematical development and top security among the former existing algorithms. As a result Elliptic Curve Cryptography for image data is developed to meet the current security needs. Application: To transmit securely image data over the wireless channels and systems and so on. Currently this work was currently developed in an ad-hoc fashion and it can be further improved with ECC binary field and various measures of security that includes different attacks.