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Quantum-secure communication and computation have garnered increasing attention due to their powerful search capabilities for certain complex problems and their ability to provide unconditional security. This indicates that classical cryptography, such as asymmetric ciphers based on complex mathematics, faces a significant threat from quantum algorithms. However, quantum cryptography can detect any attempt to eavesdrop on a channel. As a result, the investigation and implementation of quantum computers and quantum-secure communication networks have become essential objectives for numerous research teams. This paper provides an overview of quantum cryptography, including its development, and focuses on the theoretical aspect of quantum secure direct communication (QSDC). This helps readers understand the theoretical operating principles and gain a better understanding of the entire quantum characteristic and protocol operation in the QSDC field. QSDC enables secure communication without previously shared private keys, making it a crucial topic in quantum cryptography research. This paper provides an overview of several well-known versions of QSDC in theory, discussing their applications, challenges and potential future directions. [ABSTRACT FROM AUTHOR]

The pseudo-random number generator (PRNG) based on chaos has been widely used in the fields of digital communication, cryptography and computer simulation. In this paper, we study a new PRNG based on spatial surface chaotic system (SSCS), which is constructed based on coupling mapping lattice (CML) and one-dimensional Logistic chaotic map. To verify the performance of this generator, we study its nonlinear dynamic properties, including the Lyapunov exponent, ergodicity and bifurcation phenomena. Moreover, we analyze the cryptographic properties such as key space, key sensitivity, correlation, histogram and information entropy, while performing NIST SP800-22 test and TestU01 test for the randomness of this system. Theoretical analysis and numerical simulation results show that the PRNG proposed in this paper has good complexity, ergodicity, sensitivity and randomness. Moreover, the key space can increase dynamically with the increase of encrypted data, especially suitable for the protection of big data such as multimedia, which is more advantageous than most existing chaotic mapping. The results of this paper will provide a new idea for the study of chaotic cryptography, and motivate the study of new discrete chaotic models with desirable statistical properties. [ABSTRACT FROM AUTHOR]

In this paper, we changed the methodology for pixel value differencing. The proposed method work on RGB color images improves the existing PVD technique in terms of embedding capacity and overcomes the issue of falling off boundaries in the traditional PVD technique, and provides security to the secret message from histogram quantization attack. Color images are composed of three different color channels (red, green, and blue), so we cannot apply the traditional pixel value differencing algorithm to them. Due to that, the proposed technique divides the RGB photograph in red, blue, and green channels. Following that the modified pixel value differencing algorithm is employed to all successive pixels of color channels. We get the total embedding capacity by adding the embedding capacities of each color component. After embedding the data, we concatenate the color channels to get the stegoimage. On a series of color images, we tested our pixel value differencing approach and found that the stego-picture's visual excellence and payload capacity were reasonable. The variation in histogram between the stego and cover photographs was minor, making it resistant to histogram quantization attacks, and the suggested approach also solves the issue of falling off the boundary. [ABSTRACT FROM AUTHOR]

Secret-sharing is a vital topic of cryptography and has widely used in information protection. One technique to the development of secret-sharing schemes is primarily based on error-correcting codes. In this paper, we determine the minimal codewords of relative four-weight codes and have the utility in the secret sharing schemes. [ABSTRACT FROM AUTHOR]

This paper introduces an FPGA implementation of a pseudo-random number generator (PRNG) using Chen's chaotic system. This paper mainly focuses on the development of an efficient VLSI architecture of PRNG in terms of bit rate, area resources, latency, maximum length sequence, and randomness. First, we analyze the dynamic behavior of the chaotic trajectories of Chen's system and set the parameter's value to maintain low hardware design complexity. A circuit realization of the proposed PRNG is presented using hardwired shifting, additions, subtractions, and multiplexing schemes. The benefit of this architecture, all the binary multiplications (except X i ⋅ Y i and X i ⋅ Z i) operations are performed using hardwired shifting. Moreover, the generated sequences pass all the 15 statistical tests of NIST, while it generates pseudo-random numbers at a uniform clock rate with minimum hardware complexity. The proposed architecture of PRNG is realized using Verilog HDL, prototyped on the Virtex-5 FPGA (XC5VLX50T) device, and its analysis has been done using the Matlab tool. Performance analysis confirms that the proposed Chen chaotic attractor-based PRNG scheme is simple, secure, and hardware efficient, with high potential to be adopted in cryptography applications. [ABSTRACT FROM AUTHOR]

Recently, a chaotic secure video communication system based on FPGA is proposed, which essentially encrypts the original image data of each frame in the video in multiple rounds by using the 6D self-synchronizing chaotic stream cipher. In this paper, the security performance of the multiround encryption algorithm is analyzed based on divide-and-conquer attack. In the case of one round encryption, the keys ψ i j (1 ≤ i ≤ 3 , 1 ≤ j ≤ 6) can be deciphered by setting 30 appropriate initial conditions according to known-plaintext attack. After that, according to chosen-ciphertext attack, the chaotic iterative equation of the decryption end is degenerated into a linear one if ciphertexts are all set to zero. Under this condition, the equations between the unknown keys and the plaintext-ciphertext pairs can be obtained by setting 24 appropriate initial conditions, and the keys ψ i j (4 ≤ i ≤ 6 , 4 ≤ j ≤ 6) can be deciphered by solving the equations in Mathematica. Secondly, in order to reduce the multiplication times of the unknown keys in the case of two-round encryption, the number of pixels in an image can be selected as little as possible. According to chosen-ciphertext attack, when the number of the pixels in an image is only one, the keys ψ i j (1 ≤ i ≤ 3 , 1 ≤ j ≤ 6) can be deciphered by setting 30 appropriate initial conditions. Then, when the number of pixels in an image is two, the keys ψ i j (4 ≤ i ≤ 6 , 4 ≤ j ≤ 6) can be deciphered by setting 24 appropriate initial conditions. However, in the case that the encryption round is three or more, the keys cannot be deciphered by the attack method proposed in this paper. The analysis results show that the multiround image encryption algorithm is not secure when the number of encryption rounds is one or two. [ABSTRACT FROM AUTHOR]

In this paper, a new true random number generator (TRNG) based on a new variable differential ring oscillator has been presented. In this structure, the ring oscillator's jitter is considered a random phenomenon. The jitter of the proposed ring oscillator is driven by thermal noise and flicker noise so that the generated jitter is random. In this paper, a new variable differential ring oscillator has been designed. The stage of this ring oscillator is changed randomly in order to create random jitter. A new differential delay cell has been proposed to boost the speed of TRNG and random jitter. The proposed random number generator (RNG) is robust against temperature variations of − 40–120 ∘ C and voltage variations from 0.8 to 1.8 V. The proposed system's bitrate is 50 MB/s and its efficiency is 30.03 Mb/mJ. This process has been implemented in the 0.18 um CMOS process. Simulation results have been presented in Hspice software and cadence. The output bit images have been displayed by Matlab software. [ABSTRACT FROM AUTHOR]

This paper focuses on the matrix sequences that represent negative indices Pell and Pell–Lucas number. It will specifically provide the important relationships between negative indices Pell and Pell–Lucas number and Pell and Pell–Lucas matrix sequences. The research of new error correcting codes has received a lot of attention in recent years, specifically due to its potential use in quantum-resistant cryptosystems. These matrices are then applied in cryptology and have a great opportunity to report some cases that might be a mistake between the sender and the receiver by using Lucas blocking algorithm. [ABSTRACT FROM AUTHOR]

In this paper, a new 4D chaos system is introduced based on the mathematical structure through composing and transferring. The behavior of the proposed chaotic system is studied using different tests, such as Lyapunov exponent, bifurcation diagram and histogram. In order to show the advantage of the new chaos system, the proposed system is used for image encryption. In the proposed algorithm, in addition to the new chaos system, cellular automata is also used to improve the security of the algorithm. The proposed algorithm has a separate structure for encryption key, which increases the security of the proposed algorithm. The security of the proposed environment which is evaluated using different types of security tests shows the efficiency of the proposed algorithm. [ABSTRACT FROM AUTHOR]

Cellular automaton (CA) as a discrete and deterministic dynamic system has been widely used in cryptography. In this paper, a novel triple-coupling CA model is proposed. We first apply the triple-coupling model to 1D CA to design a high-quality pseudo-random number generator (PRNG). Numerical simulation and analyses show that triple-coupling CA exhibits more complex evolutionary behavior than uncoupling CA. The pseudo-random sequence generated by triple-coupling 1D CA can pass all NIST SP800-22 tests. Subsequently, the triple-coupling model is also applied to 2D CA, and a novel image encryption scheme based on this model is proposed. Thanks to the triple-coupling model, the diffusion operation can be completed between different color channels of the color image. Experimental simulations and extensive cryptanalysis show that the image encryption algorithm using the triple-coupling model has superior security and high efficiency. [ABSTRACT FROM AUTHOR]

In this paper, an image cryptosystem based on genetic central dogma (GCD), Knuth–Morria–Pratt (KMP) algorithm and a chaotic system is developed. The KMP algorithm is firstly used to bind DNA strings to obtain the next array, which participates in the design of the chaotic initial condition, and then the secure chaotic sequences are produced by employing the sliding idea in pattern string matching. In the present procedure, a DNA-level two-way pixel's shuffle is achieved by a shared stack push operation and it is adopted in the permutation module for the purpose of accelerating the overall pixel's shuffle. Subsequently, the pixel values are substituted by simulating the process of protein synthesis in GCD, in which the DNA replication and RNA replication form the basis of the DNA-triploid mutation and new RNA mutation rules, respectively. Experimental simulations and extensive cryptanalysis fully vindicate that superior security effects in addition to satisfactory low time complexity can be simultaneously obtained by the proposed confusion-substitution scheme. [ABSTRACT FROM AUTHOR]

This paper presents a reconfigurable image confusion scheme, which uses Linear Congruential Generators (LCGs)-based Pseudorandom Bits Generator (PRBG). The PRBG is based on the variable input-coupled LCG with a reconfigurable clock divider. The proposed algorithm encrypts the input image up to four times successively using different random sequences in every attempt. This new scheme aims to efficiently extract statistically strong pseudorandom sequences from a proposed PRBG with a large keyspace and simultaneously increase the security level of the encrypted image. This PRBG was initially designed on Virtex-5 (XC5VLX110T), Virtex-7 (XC7VX330T) and Artix-7 (XC7A100T) Field Programmable Gate Arrays (FPGAs). The statistical properties of the proposed PRBG for four different configurations are verified by the National Institute of Standards and Technology (NIST) tests. Thereafter, a reconfigurable encryption/decryption algorithm that uses the proposed PRBG is developed for secure image encryption. The encryption process was accomplished using the MATLAB tool after obtaining the PRBG keys from the FPGA. To show the quality and strength of the encryption process, security analysis [correlations and Number of Pixels Change Rate (NPCR)] is performed. Security analysis results are compared with the conventional encryption algorithm to show that the developed reconfigurable encryption scheme provides better results in security tests. [ABSTRACT FROM AUTHOR]

Advanced Encryption Standard (AES) has been a prevalent cryptographic structure in the world. Existing AES-related cryptographic accelerators generally face the problem of high power consumption. To deal with this challenge, this paper presents a cryptographic structure that employs iterative reuse to decrease resource utilization. Through the efficient use of delay-line RAM, the implementation of long-length key storage results in a reduction in the utilization of registers. The computational complexity of AES cryptographic algorithm is reduced by using homomorphic mapping to the inversion operation in S-box from the Galois Fields GF(28) to GF[(24)2]. Such proposed AES cryptographic accelerator is characterized by its low resource utilization and low power consumption. In addition, we have also conducted some simulation analysis to evaluate its performance. The synthesis result indicates that the AES cryptographic accelerator exhibits a 0.74% reduction in utilization of LUT and a 35% decrease in power consumption, as compared to the original version. The proposed AES cryptographic accelerator results in an area of 0.101mm2, a throughput of 12.28Gbps, and a power consumption of 2.56mW in TSMC 90nm. [ABSTRACT FROM AUTHOR]

Cellular automaton (CA) is a computing model which is emerging rapidly. It is largely used in different types of scientific applications and simulations due to its ability to solve complex problems using simple rule(s). Cellular automata (CAs) are used in different types of applications like cryptography, VLSI systems, fault detection, etc. Typically, most of these applications utilize one-dimensional, 2-state, 3-neighborhood CAs. This paper explores the concept of Next State RMT Transition Diagram (NSRTD) for characterization of all the Elementary Cellular Automata (ECA) rules in periodic boundary condition leading to the identification of all ECA rules forming more than two fixed points (referred to as Single Length Cycle Multi-Attractor CA (MACA)) for an arbitrary CA length (n). For this, the 88 Wolfram classification rules and their equivalent rules have been utilized to reduce the search complexity by avoiding exhaustive searching on all the 256 ECA rules. [ABSTRACT FROM AUTHOR]

The notion of c-differential uniformity was proposed by Ellingsen et al., which generalizes the classical differential uniformity measuring the resistance against differential cryptanalysis. Since then, the research of functions with low c-differential uniformity over finite fields attracted many researchers’ attention. However, it seems that there is no study of function with low c-differential uniformity over integer rings modulo n. In this paper, we give an extension of the c-differential uniformity concept to rings of integers module some n > 0, and we present several perfect c-nonlinear polynomial functions on the integer ring ℤn for the different integer n. [ABSTRACT FROM AUTHOR]

The use of codes defined by sparse characteristic matrices, like QC-LDPC and QC-MDPC codes, has become an established solution to design secure and efficient code-based public-key encryption schemes, as also witnessed by the ongoing NIST post-quantum cryptography standardization process. However, similar approaches have been less fortunate in the context of code-based digital signatures, since no secure and efficient signature scheme based on these codes is available to date. The main limitation of previous attempts in this line of research has been the use of sparse signatures, which produces some leakage of information about the private key. In this paper, we propose a new code-based digital signature scheme that overcomes such a problem by publishing signatures that are abnormally dense, rather than sparse. This eliminates the possibility of deducing information from the sparsity of signatures, and follows a recent trend in code-based cryptography exploiting the hardness of the decoding problem for large-weight vectors, instead of its classical version based on small-weight vectors. We focus on one-time use and provide a first parameterization of the new scheme, the main advantages of which are very fast signature generation and verification, and public keys that are not too large for a code-based signature scheme. [ABSTRACT FROM AUTHOR]

One of the most significant challenges appears to be securing the Internet of Things (IoT) communication network. As a corollary, information security has become the basis for establishing trustworthiness in IoT network communication. Cryptography is one of the ways for securing information in this case. However, the majority of current approaches are static, making them subject to security threats. As a consequence, a new concept, dynamic encryption, is growing rapidly in IoT communication. In this paper, a dynamic encryption algorithm (DSIT) has been proposed to secure IoT communication. This algorithm is based on Feistel and Substitution–Permutation Network. DSIT is a block cipher that takes the 64-bit block of plaintext, 64-bit secret key, and a secret dynamic box (D-box) as input. It produces a 64-bit ciphertext by performing eight rounds of the DSIT algorithm. For each round, the key and D-box are updated. This dynamic effect provides high security to a dynamic IoT network. The proposed algorithm has been executed in IoT environment using Raspberry Pi 3 Model B + and 50% average Avalanche effect has been achieved. The proposed algorithm efficiently encrypts the image data to secure the communication and high resistant to cryptanalysis attacks. [ABSTRACT FROM AUTHOR]

Day by day, the requirement for secure communication among users is rising in a digital world, to protect the message from the undesirable users. Steganography is a methodology that satisfies the user's necessity of secure communication by inserting a message into different formats. This paper proposes a secret key-based image steganography to secure the message by concealing the grayscale image inside a cover image. The proposed technique shares the 20 characters long secret key between two clients where the initial eight characters of a secret key are utilized for bit permutation of characters and pixels while the last 12 characters of secret key decide the encryption keys and position of pixels of a grayscale image into the cover. The grayscale image undergoes operation such as encryption and chaotic baker followed by its hiding in a cover to form a stego image. The execution of the proposed strategy is performed on Matlab 2018. It shows that the proposed approach manages to store the maximum message of size 16 KB into the cover of size 2 5 6 × 2 5 6. The image quality of stego images has been evaluated using PSNR, MSE. For a full payload of 16 KB, PSNR is around 51 dB to 53 dB which is greater than satisfactory PSNR. [ABSTRACT FROM AUTHOR]

This paper proposes an information hiding algorithm using matrix embedding with Hamming codes and histogram preservation in order to keep the histogram of the image unchanged before and after hiding information in digital media. First, the algorithm uses matrix embedding with Hamming codes to determine the rewriting bits of the original image, rewrite and flip them, and successfully embed the secret information. Then, according to the idea of a break-even point, a balanced pixel frequency adaptive algorithm is proposed and each embedded bit of secret information is detected and compensated by the adjacent bit of histogram data, so that the histogram change of the image before and after information hiding is minimized. At present, most of the histogram distortion values after steganography are generally over 1000 or even higher. As a contrast, the method proposed in this paper can keep the histogram distortion values to be less than 1000. The feasibility and effectiveness of the algorithm are verified by relative entropy analysis as well. The experimental results also show that the algorithm performs well in steganographic analyses of images. [ABSTRACT FROM AUTHOR]

Due to the huge advancement in technology, digitizing the multimedia content like text, images and videos has become easier. Everyday huge amounts of multimedia content are shared through the social networks using internet. Sometimes this multimedia content can be hacked by the hackers. This will lead to the misuse of the data. On the other hand, the medical content needs high security and privacy. Motivated by this, joint secured medical image compression–encryption mechanisms are proposed in this paper using multiscale transforms and symmetric key encryption techniques. The multiscale transforms involved in this paper are wavelet transform, bandelet transform and curvelet transform. The encryption techniques involved in this paper are international data encryption algorithm (IDEA), Rivest Cipher (RC5) and Blowfish. The encoding technique used in this paper is embedded block coding with truncation (EBCOT). Experimental results are done for the proposed works and evaluated by using various parameters like Peak Signal-to-Noise Ratio (PSNR), Mean Square Error (MSE), Image Quality Index (IQI) and Structural Similarity Index (SSIM), Average Difference (AD), Normalized Cross-correlation (NK), Structural Content (SC), Maximum difference (MD), Laplacian Mean Squared Error (LMSE) and Normalized Absolute Error (NAE). It is justified that the proposed approaches in this paper yield good results. [ABSTRACT FROM AUTHOR]

In this paper, we present a new encryption scheme using generalization k-Fibonacci-like sequence, we code the points of an elliptic curve with the terms of a sequence of k-Fibonacci-like using of Fibonacci sequence and we call it as k-Fibonacci like sequence { V k , n } defined by the recurrence relation: V k , n + 1 = k V k , n + V k , n − 1 ; n ≥ 1 , V k , 0 = 2 m (k + 1) , V k , 1 = p k + k (k + 1) m (1) and we present some relation among k-Fibonacci like sequence, k-Fibonacci sequence and k-Lucas sequence. After that, we give application of elliptic curves in cryptography using k-Fibonacci like sequence. [ABSTRACT FROM AUTHOR]

This paper proposes a new four-dimensional hyper-chaotic system capable of generating multi-wing chaotic attractors by introducing active magnetron memristors, multi-segmented square functions and trigonometric functions. The dynamical properties of this new hyper-chaotic system, such as equilibrium point, dissipation, Lyapunov exponential spectrum, bifurcation diagram and Poincaré cross-section and attraction basin, are analyzed theoretically and simulated numerically, and the complexity of this system with different parameters is analyzed. It is observed that this hyper-chaotic system has periodic, chaotic and hyper-chaotic variations with an infinite number of equilibria and coexisting attractors under different parameter conditions. The circuit simulation was performed using Multisim and the results obtained were consistent with the numerical analysis of the dynamics, and the chaotic circuit system is designed by FPGA to verify the realizability of the system. Finally, an image encryption algorithm is designed in conjunction with the DNA algorithm to enable a new system chaotic sequence for image encryption. The results show that the hyper-chaotic system has rich dynamical behavior and has high-security performance when applied to image encryption with strong chaotic key and plaintext sensitivity and large key space in image encryption. [ABSTRACT FROM AUTHOR]

Lightweight cryptography has been proposed recently as an attractive solution to provide security for the ever-growing number of IoT resource-constrained devices. Many of the proposed lightweight cryptographic ciphers have been implemented in software. However, for practical embedded IoT applications, hardware implementations are preferred because they have small silicon area and low-power consumption. In this paper, we present a transistor-level hardware implementation of the well-known KATAN lightweight cipher. This cipher has been chosen due to its operational simplicity and high levels of security. Moreover, the structure of the KATAN cipher lends itself naturally for transistor-level hardware implementation. The design has been implemented at the transistor level using the advanced new 28-nm CMOS technology which facilitates optimized designs for the resource-constrained IoT devices. The proposed VLSI KATAN encryption and decryption circuits have been designed and simulated using the Synopsys Custom Designer Tool using 28-nm technology, 0.9 v supply voltage and a 1 GHz clock signal. The KATAN encryption circuit has 312 GE (Gate Equivalent) without key and irregular update registers, and 1081 GE for the overall design, and the decryption circuit has 390 GE without memory registers and 6867 GE for the overall design. [ABSTRACT FROM AUTHOR]

Recently, He proposed a novel quantum private comparison protocol without a third party (G. P. He, Int. J. Quantum Inf. 15(2) (2016) 1750014). This paper points out that two security loopholes in He's protocol are existent. And a new QPC protocol which can avoid these loopholes is proposed without the help of a third party in this paper. [ABSTRACT FROM AUTHOR]

Due to its advantage of quantum resistance and the provable security under some worst-case hardness assumptions, lattice-based cryptography is being increasingly researched. This paper tries to explore and present a novel lattice-based public key cryptography and its implementation of circuits. In this paper, the LWE (learning with error) cryptography is designed for circuit realization in a practical way. A strategy is proposed to dramatically reduce the stored public key size from m ⋅ ( n + l ) 2 q to m ⋅ l ⋅ log 2 q , with only several additional linear feedback shift registers. The circuit design is implemented on Xilinx Spartan-3A FPGA and performs very well with limited resources. Only 125 slices and 8 BRAMs are occupied, and there are no complex operation devices such as multipliers or dividers, all the involved arithmetic operations are additions. This design is smaller than most hardware implementations of LWE or Ring-LWE cryptography in current state, while having an acceptable frequency at 111 MHz. Therefore, LWE cryptography can be practically realized, and its advantages of quantum resistance and simple implementation make the public key cryptography promising for some applications in devices such as smart cards. [ABSTRACT FROM AUTHOR]

In this paper, we mathematically associate crypto-cloud computing with cooperative game theory in the presence of fuzzy uncertainty. For this purpose, we retrieve information from the database of Amazon Web Service. Then we construct a secure crypto-cloud game theoretical model and apply this model to online games under fuzzy uncertainty. Further, we suggest some fuzzy game theoretical solutions by proposing a novel twisted Edwards curve pairing-based scheme over finite fields having the property of indistinguishable under chosen ciphertext attacks. Finally, it is seen that costs of the numerical fuzzy solutions are reduced and their efficiency is increased compared with the numerical crisp ones. [ABSTRACT FROM AUTHOR]

In this paper, a steganography algorithm has been proposed which is based on quantization table modification and image scrambling in the DCT domain. First, the algorithm homogenizes the energy by scrambling the cover image to improve the number of DCT coefficients suitable for information embedding. Second, the embedding capacity of the DCT block is determined by the value of the quantization table in the algorithm, different quantization tables get different embedding effects. In addition, this paper proposes an optimized modified quantization table. Extensive experiments show that the proposed algorithm achieves a great potential for confidential data and indiscernible image quality. [ABSTRACT FROM AUTHOR]

Chaos has been used in cryptography for years and many chaotic cryptographic systems have been proposed. Their securities are often evaluated by conducting conventional statistical tests, however few studies have referred to the security issue of the chaotic hardware cryptographic systems. This paper evaluates the security of the chaotic cryptographic system from a hardware perspective by using the side channel analysis attack. First, a chaotic block cryptosystem is designed and implemented based on an Atmel microcontroller. Then the conventional statistical security tests, including SP 800-22 test, characters frequency test, avalanche test, are used to verify its security performance. In the meantime, the correlation power analysis attack is carried out for the security evaluation. Experimental results demonstrate that even though the chaotic cryptographic system can pass the conventional statistical tests, it still has the probability to be attacked from a hardware perspective using the leaked side channel information such as execution time and power consumption. This paper proposes another way to analyze the security of the chaotic cryptosystem, which can aid designing mechanisms to enhance the security of the hardware cryptosystems in the future. [ABSTRACT FROM AUTHOR]

We investigate the spatiotemporal dynamics with fractional order differential logistic map with delay under nonlinear chaotic maps for spatial coupling connections. Here, the coupling methods between lattices are the nonlinear chaotic map coupling of lattices. The fractional order differential logistic map with delay breaks the limits of the range of parameter in the classical logistic map for chaotic states. The Kolmogorov-Sinai entropy density and universality, and bifurcation diagrams are employed to investigate the chaotic behaviors of the proposed model in this paper. The proposed model can also be applied for cryptography, which is verified in a color image encryption scheme in this paper. [ABSTRACT FROM AUTHOR]

In this paper, a new 3D discrete hyperchaotic system is constructed, and its Lyapunov exponent and approximate entropy are calculated. We adopt the drive-response method and self-adaptive method to make the hyperchaotic system to reach synchronization, and then design an encrypted transmission system based on the synchronization of this discrete hyperchaotic system. In the synchronous hyperchaotic system, the initial value related to the hash value of the speech signal of the chaotic system is designed. Some security analyses are studied in detail. [ABSTRACT FROM AUTHOR]

The key-scheduling algorithm in the AES is the component responsible for selecting from the master key the sequence of round keys to be xor-ed to the partially encrypted state at each iteration. We consider here the group Γ generated by the action of the AES-128 key-scheduling operation, and we prove that the smallest group containing Γ and all the translations of the message space is primitive. As a consequence, we obtain that no linear partition of the message space can be invariant under its action. [ABSTRACT FROM AUTHOR]

Fuzzy graph theory is finding an increasing number of application in modeling real time systems where the level of information inherent in the system varies with different levels of precision. Special fuzzy graph can be obtained from two given fuzzy graphs using the operations beta products. In this paper, we introduce the notions of some kinds of beta product of two fuzzy graphs. The concept of strong, regular and complement of β i -product of two fuzzy graphs and relation between them are also obtained. At the end, an application with a cryptographic object is said to be using the β i -product of fuzzy graphs. [ABSTRACT FROM AUTHOR]

Quantum steganography is the art of hiding the fact that communications, which transmit the secret message in an insecure quantum channel, are occurring. This paper presents a novel quantum steganography protocol based on probability measurements for transmitting n qubits secret message in an insecure quantum channel. In the protocol, senders embed the secret message into the cover data by POVM measurements. Then, receivers can correctly extract the secret message and recover the cover data with a certain probability by selecting two sets of appropriate protective measurement operators to act projective measurements, respectively. More importantly, the existence of the secret message has no influence on the cover data. In addition, the security of our protocol does not rely on other protocols. The paper analyzes the secrecy and the security in detail. [ABSTRACT FROM AUTHOR]

In this paper, we present a novel technique for security of two-dimensional data with the help of cryptography and steganography. The presented approach provides multilayered security of two-dimensional data. First layer security was developed by cryptography and second layer by steganography. The advantage of steganography is that the intended secret message does not attract attention to itself as an object of scrutiny. This paper proposes a novel approach for encryption and decryption of information in the form of Word Data (.doc file), PDF document (.pdf file), Text document, Gray-scale images, and RGB images, etc. by using Vigenere Cipher (VC) associated with Discrete Fourier Transform (DFT) and then hiding the data behind the RGB image (i.e. steganography). Earlier developed techniques provide security of either PDF data, doc data, text data or image data, but not for all types of two-dimensional data and existing techniques used either cryptography or steganography for security. But proposed approach is suitable for all types of data and designed for security of information by cryptography and steganography. The experimental results for Word Data, PDF document, Text document, Gray-scale images and RGB images support the robustness and appropriateness for secure transmission of these data. The security analysis shows that the presented technique is immune from cryptanalytic. This technique further provides security while decryption as a check on behind which RGB color the information is hidden. [ABSTRACT FROM AUTHOR]

A highly secure communication method is essential for end users for the exchange of information which is not interpreted by an intruder. Cryptography plays a crucial role in the current and upcoming digital worlds, for secure data transmission in wired and wireless networks. Asymmetric and symmetric cryptographic algorithms encrypt data against vulnerable attacks and transfer to authenticated users. Steganography is a method for providing secure information with the help of a carrier file (text, video, audio, image, etc.). This paper proposes Deoxyribonucleic Acid (DNA)-based asymmetric algorithm which is used to encrypt the patient's secret information and its performance is compared with ElGamal, RSA and Diffie–Hellman (DH) cryptographic algorithms. The proposed asymmetric algorithm is applied to image steganography which is used for encrypting and concealing the patient's secret information in a cover image. The proposed method consumes less hardware resources with improved latency. Dynamic Partial Reconfiguration (DPR) allows to transform a selective area rather than complete shutdown of the entire system during bitstream configuration. Cryptosystem with DPR is designed, synthesized in Xilinx Vivado and simulated in Vivado simulator. The design is targeted at Basys3, Nexys4 DDR and Zync-7000 all-programmable SOC (AP SoC) architectures and programmed with secure partial bit files to avoid vulnerable attacks in the channel. [ABSTRACT FROM AUTHOR]

Chaotic maps have been widely used in image encryption due to their complexity, pseudorandomness and high sensitivity to initial values. In this paper, an image encryption algorithm based on a 4D chaotic map and steganography is proposed. The algorithm consists of two rounds of encryption and one operation of embedding hash. In the first round of encryption, the hash value of plaintext image is used to control the generation of chaotic sequences, which makes the encryption algorithm highly relevant to the content of the image. Then, the hash value is embedded into the intermediate image according to the idea of steganography. In the second round of encryption, the image is encrypted under the control of another set of chaotic sequences to hide the hash value and further enhance the security of the algorithm. Different from other algorithms, our algorithm does not need to additionally transmit the hash value to the decryptor through a special channel. It has good availability and adaptability. Experimental results and security analysis demonstrate that the algorithm has high security performance and can resist various attacks. [ABSTRACT FROM AUTHOR]

This paper presents cryptanalysis of a color image encryption scheme. DNA encoding and multiple 1D chaotic maps are used in the encryption process which increases its computational speed. The key streams generated in this scheme are dependent on secret keys, updated using the sum of pixel intensities of plain image of size W × H × 3. This paper analyzes the security of encryption scheme against the chosen plaintext attack and finds that only 𝒪 (7 6 8 W H) different key matrices for diffusion are possible, an equivalent version of which can be revealed with 𝒪 (7 6 8 W H) chosen plain images. Experimental results are presented to prove that equivalent diffusion keys and block permutation sequence can be effectively revealed through the attack. In addition, low sensitivity of keys towards changes in plaintext along with insecure diffusion process involved in encryption process is also reported. Finally, to remedy the shortcomings of the original encryption scheme, an enhanced encryption scheme is generated that can resist chosen/known plaintext attack while maintaining the merits of the original encryption scheme. [ABSTRACT FROM AUTHOR]

In this paper, a high speed elliptic curve cryptographic (ECC) processor for National Institute of Standards and Technology (NIST) recommended prime P − 2 5 6 is proposed. The modular arithmetic components in the proposed ECC processor are highly optimized at both architectural level and circuit level. Redundant-signed-digit (RSD) arithmetic is adopted in the modular arithmetic components to avoid lengthy carry propagation delay. A high speed modular multiplier is designed based on an efficient segmentation and pipelining strategy. The clock cycle count is reduced as result of the segmentation, whereas operating frequency and throughput are significantly increased due to the pipelining. An optimized pipelined architecture for modular division is also presented which is suitable for the design of ECC processor using projective coordinates. The Joye's double and add (DAA) algorithm based on X Y -only common Z (co- Z) coordinate is adopted at the system level for its regular and efficient behavior. The proposed ECC processor is flexible and can be implemented using any field programmable gate array (FPGA) family or standard cell libraries. The proposed ECC processor executes a single elliptic curve (EC) point multiplication (PM) operation in 0.47 ms at a maximum frequency of 327 MHz on Virtex-6 FPGA. The implementation results demonstrate that the proposed ECC processor outperforms the other contemporary designs reported in the literature in terms of speed and area × time metrics. [ABSTRACT FROM AUTHOR]

This paper corrects some mistakes about three theorems, two figures and some expressions on "finite field" in a literature, and then it analyzes the digraphs and period properties of the logistic map on residue class rings Z (3 n) and Z (p n). Some theorems and conjectures are proved or given. To validate these properties, we make some numeral experiments and draw the relative figures and tables. So the theoretical analysis and numeral experiments show that there exists periods in the logistic map on Z (3 n) and on Z (p n) and it can be applied in the pseudo-random generators, cryptography, spread spectrum communications and so on. [ABSTRACT FROM AUTHOR]

Symmetric and asymmetric cryptographic algorithms are used for a secure transmission of data over an unsecured public channel. In order to use these algorithms in real-time applications, many flexible hardware architectures have been proposed and implemented with multiple design constraints. Therefore, a systematic study is required to analyze various implementation approaches. This paper has focused on the identification and classification of recent research practices pertaining to the flexible hardware implementation of cryptographic algorithms. We have used Systematic Literature Review (SLR) process to identify 51 research articles, published during 2008–2017. The identified researches have been classified according to three design approaches: (1) crypto processor, (2) crypto coprocessor and (3) multicore crypto processor. Consequently, a comparative analysis of various cryptographic algorithms in terms of flexibility, throughput, area, power and implementation technology has been presented. A comprehensive investigation of flexible architectures for implementing cryptographic algorithms facilitates researchers and designers of the domain to select an appropriate design approach for a particular algorithm and/or application according to their needs. [ABSTRACT FROM AUTHOR]

Rabbit is a stream cipher proposed by M. Boesgaard et al., and has been selected into the final portfolio after three evaluation phases of the ECRYPT Stream Cipher Project (eSTREAM). So far only a few papers studied its security besides a series of white papers by the designers of Rabbit. Recently we presented a new idea to evaluate the security of a word-oriented stream cipher algorithm from a smaller data granularity instead of its original data granularity and applied it successfully to the stream cipher SOSEMANUK. In this work we apply the same idea to the Rabbit algorithm and analyze its security in resistance against the guess and determine attack from the view point of byte units. As a result, we present two new approaches of solving all xj,t+1's and gj,t's from the next-state function and the extraction scheme of Rabbit, whose complexities are 2166 and 2140.68 respectively, which are dramatically lower than those proposed by Lu et al. (2192 and 2174 resp.) at ISC 2008. Finally based on the above new results we propose a byte-based guess and determine attack on Rabbit, which only needs a small segment of known keystream to recover the whole internal state of Rabbit with time complexity 2242. Though the complexity of our attack is far higher than that of a brute force (2128), we believe that some new techniques adopted in this paper are of interest for future work on Rabbit. [ABSTRACT FROM AUTHOR]

The demand for high performance, low power/secured handheld equipment increased the need for high speed/low energy and efficient encryption/decryption algorithms. Recently, efficient techniques were suggested to increase the standard of security as well as the speed of portable and handheld devices. Also, those techniques cause increment in the lifetime of battery by reducing the total silicon capacitance and minimizing the switching activity. This paper presents two approaches to reduce the number of logic gates at S7 and S9 of MISTY1 in order to reduce the total delay time, power dissipation and silicon area. The Logic Gate Reduction Approach (LGRA) reduces the number of logic gates by applying Boolean Algebra rules and simplifications, while the Duplicated Gate Reduction Approach (DGRA) removes the redundant XOR and AND logic gates which form the S7 and S9 blocks ciphers. The LGRA approach shows that the throughput enhanced by 21.1% compared to the conventional design, the silicon area reduced by 26.8%, while the dynamic power dissipation is reduced by 21.7% on average. The DGRA approach shows that the throughput enhanced by 3.8% compared to the conventional design, the silicon area reduced by 31.7%, while the dynamic power dissipation is reduced by 27% on average. As a result, the proposed approaches could be fit for next generation of handheld and portable devices. [ABSTRACT FROM AUTHOR]

VLSI technology makes the integration of multiple electronic components into a single electronic chip possible but Moore has already predicted that further miniaturization of VLSI chips will cause excess heat dissipation. Because of this impediment faced by this technology, the scientists have turned their focus to nano-technological alternatives to keep up the continuous device improvement and continue with the miniaturization procedure without facing any hurdle from the aspect of heat dissipation and space and time complexity. Memristor can be such a nano-alternative, which has the potential of very rapid execution, miniaturization and very low power consumption compared to transistor-based technology. The main objective of this paper is to show an application of symmetric function in cryptography. In order to do so, first, three-input and five-input symmetric functions are implemented in memristor-based nanocrossbar circuits. Then a dynamic circuit of symmetric functions is implemented where the input voltages convert the circuit to three-input or five-input symmetric function circuit as and when required. The simulation results show the satisfactory behavior of our proposed design. [ABSTRACT FROM AUTHOR]

The aim of this paper is to construct a relation between tribonacci numbers and generalized tribonacci numbers. Besides, certain conditions are obtained to generalize the representation of a positive integer N which is determined in [S. Badidja and A. Boudaoud, Representation of positive integers as a sum of distinct tribonacci numbers, J. Math. Statistic. 13 (2017) 57–61] for a k -generalized Fibonacci numbers (F n (k)) n ∈ ℕ ∗ . Lastly, some applications to cryptography are given by using (F n (k)) n ∈ ℕ ∗ . [ABSTRACT FROM AUTHOR]

In this paper, a cryptanalysis method that combines a chosen-ciphertext attack with a divide-and-conquer attack by traversing multiple nonzero component initial conditions (DCA-TMNCIC) is proposed. The method is used for security analysis of n -D (n = 3 , 4 , 5 , 6 , 7 , 8) self-synchronous chaotic stream ciphers that employ a product of two chaotic variables and three chaotic variables (n -D SCSC-2 and n -D SCSC-3), taking 3-D SCSC-2 as a typical example for cryptanalysis. For resisting the combinational effect of the chosen-ciphertext attack and DCA-TMNCIC, several improved chaotic cipher schemes are designed, including 3-D SCSC based on a nonlinear nominal system (3-D SCSC-NNS) and n -D SCSC based on sinusoidal modulation (n -D SCSC-SM (n = 3 , 4 , 5 , 6 , 7 , 8)). Theoretical security analysis validates the improved schemes. [ABSTRACT FROM AUTHOR]

Due to the technological advancements in digital communication, the amount of multimedia content over the internet has increased manifold in past decade. This has renewed the internet of researchers in the area of privacy and secure communication. This paper presents a secure and robust video steganography method in discrete cosine transform (DCT) domain. In order to enhance the security of the proposed algorithm, the frame selection process is randomized and the secret data are pre-treated using Arnold's cat map. The secret data are embedded in the middle band DCT coefficient using two pseudo random sequences. These sequences are generated using a chaotic map. We analyze the proposed algorithm in terms of peak signal-to-noise ratio (PSNR), structural similarity index (SSIM), multi-scale structural similarity index (MSSIM) and video quality metric (VQM). The evaluation has been done on 107 video sequences. The experimental results demonstrate that the algorithm maintains acceptable video quality. The robustness of the proposed method is tested under Gaussian and salt and pepper noise attack using correlation between original and recovered images. The proposed algorithm is able to recover 90.60% data without error under salt and pepper noise (D = 0. 0 0 1) attack and 87.23% data correctly under Gaussian noise attack with mean = 0 and variance = 0. 0 0 1. [ABSTRACT FROM AUTHOR]

This paper introduces an efficient and scalable cloud-based privacy preserving model using a new optimal cryptography scheme for anomaly detection in large-scale sensor data. Our proposed privacy preserving model has maintained a better tradeoff between reliability and scalability of the cloud computing resources by means of detecting anomalies from the encrypted data. Conventional data analysis methods have used complex and large numerical computations for the anomaly detection. Also, a single key used by the symmetric key cryptographic scheme to encrypt and decrypt the data has faced large computational complexity because the multiple users can access the original data simultaneously using this single shared secret key. Hence, a classical public key encryption technique called RSA is adopted to perform encryption and decryption of secure data using different key pairs. Furthermore, the random generation of public keys in RSA is controlled in the proposed cloud-based privacy preserving model through optimizing a public key using a new hybrid local pollination-based grey wolf optimizer (LPGWO) algorithm. For ease of convenience, a single private server handling the organization data within a collaborative public cloud data center when requiring the decryption of secure sensor data are allowed to decrypt the optimal secure data using LPGWO-based RSA optimal cryptographic scheme. The data encrypted using an optimal cryptographic scheme are then encouraged to perform data clustering computations in collaborative public servers of cloud platform using Neutrosophic c-Means Clustering (NCM) algorithm. Hence, this NCM algorithm mainly focuses for data partitioning and classification of anomalies. Experimental validation was conducted using four datasets obtained from Intel laboratory having publicly available sensor data. The experimental outcomes have proved the efficiency of the proposed framework in providing data privacy with high anomaly detection accuracy. [ABSTRACT FROM AUTHOR]

After introducing the notion of hypergroups by Marty, a number of generalizations of this fundamental concept has been studied. In this paper, we study a special type of hypergroups; single power cyclic hypergroups and present some of their properties. First, we determine the fundamental group of single power cyclic hypergroups. Next, we construct onto homomorphisms from any single power cyclic hypergroup to another defined hypergroups. Finally, we characterize all commutative single power cyclic hypergroups of order two. [ABSTRACT FROM AUTHOR]

No abstract received. [ABSTRACT FROM AUTHOR]

Fuzzy identity-based encryption (FIBE) scheme is a kind of identity-based encryption (IBE) scheme, in which any user's identity is composed by a set of attributes and any ciphertext encrypted under identity ID can be decrypted by using a private key corresponding to identity ID′ if ID′ is close to ID as measured by some metric. Due to the error-tolerance property, FIBE scheme is very useful in real-world applications. However, most FIBE schemes are provable secure only in a weaker security model. In order to eliminate this problem, Ren et al. recently proposed a new FIBE scheme and proved that it is fully chosen-ciphertext secure in the standard model. Unfortunately, in this paper, we will show that their FIBE scheme is even not chosen-plaintext secure. [ABSTRACT FROM AUTHOR]