Pseudo-random Generator Research Articles

A high speed pseudo-random bit generator driven by 2D-discrete hyperchaos

Pseudo-Random Number Generators (PRNGs) yielding numbers with high rates and good randomness quality are crucial for security as networks expand in an ever-connected way. In this work, firstly, we construct a new 2D discrete hyper-chaotic map with linear cross-coupled topological structure combined with the Tent and Logistic map. The proposed map with the aforementioned structure enables it to outperform other enhanced chaotic maps developed recently. Secondly, an efficient PRNG based on the proposed one is implemented on the field-programmable gate array (FPGA) Xilinx xc7k325tffg900-2. Compared with those typical PRNGs, the sequences generated by ours own a high level of randomness and passed the well-known TestU01, Dieharder, and the National Institute of Standards and Technology (NIST) SP800-22 test suite successfully without post-processing. Experimental results show that the proposed PRNG occupies merely 1.4 percent of the resources available on the targeted FPGA despite it yielding numbers with a large bit depth. In addition, the timing report shows the system can operate effectively at a clock of 158 MHz with a maximum throughput of 9.26 Gbps which outperforms the state-of-the-art.

ФОРМИРОВАНИЕ ОДНОПОЛОСНОЙ КВАДРАТУРНОЙ ФАЗОВОЙ МАНИПУЛЯЦИИ РАДИОСИГНАЛОВ НА ПОДНЕСУЩИХ ЧАСТОТАХ В КОГЕРЕНТНОЙ ОПТИЧЕСКОЙ СИСТЕМЕ КОММУНИКАЦИИ

The coherent optical communication technology allows to create a transmission system overlong distances with high bandwidth. Higher order modulation formats such as Quadrature PhaseShift Keying (QPSK) provide high data rates in a simple, reliable and cost-effective manner. Thesemulti-bit modulation methods are transmitted as a symbol implementing simple in-phase andquadrature (IQ) modulation formats. To increase throughput in coherent optical systems, opticalsubcarrier multiplexing is used, when several radio signals are multiplexed on one optical carrier.This multiplexing is limited by double sideband, resulting in reduced received subcarrier powerand degraded carrier-to-noise ratio. To accumulate these effects, many ways of implementingoptical single sideband (OSSB) are proposed. The paper proposes an analysis of a coherent opticaltransmission system for generating single-sideband QPSK modulation using an optical I/Qmodulator and M-ary RF pulse shaping. The pseudo-random bit sequence generator generates a10 Gb/s modulation baseband signal. Each bit sequence is converted into an M-ary sequence ofsymbols from binary signals using phase shift keying (PSK). The M-ary pulse generator generatesa multi-level pulse shaping according to the sequence of M-ary input symbols. Electrical pulsesare applied to the electrodes of the electro-optical modulator according to the Mach–Zehnderinterferometer (MZM) scheme. The I/Q modulator operated at the quadrature operating point inboth the in-phase and quadrature branches, with an extinction ratio 60 dB and 3 V switching voltage.The light wave is emitted by a CW laser with a wavelength of 1550 nm.

Combined Pseudo-Random Sequence Generator for Cybersecurity

Random and pseudo-random number and bit sequence generators with a uniform distribution law are the most widespread and in demand in the market of pseudo-random generators. Depending on the specific field of application, the requirements for their implementation and the quality of the generator's output sequence change. In this article, we have optimized the structures of the classical additive Fibonacci generator and the modified additive Fibonacci generator when they work together. The ranges of initial settings of structural elements (seed) of these generators have been determined, which guarantee acceptable statistical characteristics of the output pseudo-random sequence, significantly expanding the scope of their possible application, including cybersecurity. When studying the statistical characteristics of the modified additive Fibonacci generator, it was found that they significantly depend on the signal from the output of the logic circuit entering the structure. It is proved that acceptable statistical characteristics of the modified additive Fibonacci generator, and the combined generator realized on its basis, are provided at odd values of the module of the recurrent equation describing the work of such generator. The output signal of the combined generator has acceptable characteristics for a wide range of values of the initial settings for the modified additive Fibonacci generator and the classic additive Fibonacci generator. Regarding the use of information security, it is worth noting the fact that for modern encryption and security programs, generators of random numbers and bit sequences and approaches to their construction are crucial and critical.

A Novel Image Encryption Technique Using Multi-Coupled Map Lattice System with Generalized Symmetric Map and Adaptive Control Parameter

Image and video data make up a significant portion of the content shared over the Internet and social media. The use of image and video communication allows more information to be shared while simultaneously presenting higher risks in terms of data security. The traditional encryption schemes are general purpose; however, to encrypt image and video data, application-specific encryption solutions are needed. An image or a video frame comprises a two-dimensional matrix where pixel intensity values are integers in range [0,255], leading to data redundancy problems. Moreover, the bulk amount of image and video data adds another challenge when deploying security primitives. In this paper, a novel coupled map lattice system-based image cryptosystem has been proposed that uses generalised symmetric maps for generation of pseudo-random sequences. The generalization of symmetric maps allows the user to choose the source of pseudo-random sequence generation by varying a single control parameter. Other adaptive control parameters ensure an adequate degree of randomness in the generated sequences. The proposed encryption system relies on three independent sources of pseudo-random sequence generators, which are further re-randomized before the final encryption process. Comprehensive experimentation has been performed to test the proposed system against various attack models on publicly available datasets. A detailed comparative analysis has also been conducted with existing state-of-the-art image encryption techniques. Results show that the proposed algorithm provides high information entropy, negative correlation, large key space, and high sensitivity to key variations, and is resistant to various types of attacks, including chosen-text, statistical, and differential attacks.

VLSI Implementation of Ternary Operand Binary Addition Using Parallel Prefix Adder for Area Efficiency

Cryptographic applications and pseudo random generator perform modular arithmetic three operand is the basic fundamental unit used in all these applications. For performing three operand additions, CSA (carry save adder) is one of the most widely used adders[5]. But in CSA in the final stage, carry is propagated which impacts the delay. Prefix parallel adders are therefore employed to get around this. The parallel prefix adders use more space even though performance in terms of latency is improved. Parallel prefix adders can also be used to build three operand adders. A brand-new, high-speed, and hardware-efficient adder technique is used to boost performance in terms of latency and area. This adder approach uses four stages to achieve three operand addition. Since Han Carlson adder is used in third stage, the suggested adder is not area efficient. To overcome this, in this paper we are replacing the Han Carlson parallel prefix adder with sklansky adder.

G-VCFL: Grouped Verifiable Chained Privacy-Preserving Federated Learning

Federated learning, as a typical distributed learning paradigm, shows great potential in Industrial Internet of Things, Smart Home, Smart City, etc. It enables collaborative learning without data leaving local users. Despite the huge benefits, it still faces the risk of privacy breaches and a single point of failure for aggregation server. Adversaries can use intermediate models to infer user privacy, or even return incorrect global model by manipulating the aggregation server. To address these issues, several federated learning solutions focusing on privacy-preserving and security have been proposed. However, theses solutions still faces challenges in resource-limited scenarios. In this paper, we propose G-VCFL, a grouped verifiable chained privacy-preserving federated learning scheme. Specifically, we first use the grouped chain learning mechanism to guarantee the privacy of users, and then propose a verifiable secure aggregation protocol to guarantee the verifiability of the global model. G-VCFL does not require any complex cryptographic primitives and does not introduce noise, but enables verifiable privacy-preserving federated learning by utilizing lightweight pseudorandom generators. We conduct extensive experiments on real-world datasets by comparing G-VCFL with other state-of-the-art approaches. The experimental results and functional evaluation indicate that G-VCFL is efficient in the six experimental cases and satisfies all the intended design goals.

Chaos Based Pseudo Random Bit Generator Design and Its Application in Secure Image Encryption

Security and privacy problems in communication systems and social media platforms where digital image/video are shared almost always, have attracted researchers interest on information security. Starting from this point of view, a novel one-dimensional chaotic maps based pseudo random bit generator is proposed to make a significant contribution to the literature about protection of personal data in any network. Electronic circuit realizations of Logistic and Tent maps as entropy source are designed on Orcad-Pspice environment and state variables are inputted to novel post-processor algorithm. The rest of main blocks of proposed pseudo random bit generator design are built up fixed-point binary conversion algorithm, XOR processor and H function post-processor. The generated pseudo random bit series are tested by using NIST 800.22 statistical test suite and applied to color image encryption in order to show the effectiveness of proposed design. Cryptanalysis processes such as histogram, NPCR-UACI and correlation analysis are demonstrated. Analysis results show that the proposed design can be used successfully in many secure communication and media transmission applications.

Implementasi Algoritma RC4A Dalam Pengamanan Citra Digital

Digital images that are private and confidential are very vulnerable to wiretapping by irresponsible parties, especially if the images are distributed via the internet. The act of theft and abuse of secret images of course can harm the image owner. One of the techniques to reduce the above problems is by using cryptographic techniques. Cryptographic techniques can secure images by means of digital image encryption by implementing the RC4A algorithm then using the initial keyword as input in the process carried out to generate new, more random keywords, based on the Key Schedule Algorithm. (KSA) and pseudo random generation algorithm (PRGA). To determine the comparison between the original image (PlainImage) and the original image (CipherImage), processing was carried out with MeanSquareError (MSE) and PeakSiqnalToNoiseRation (PSNR). The results of this study were digital images encrypted with the RC4A algorithm in terms of time differences and image results after encryption where the time used to encrypt is shorter than the description and the image results before encryption are not the same after encryption.

Nearly Optimal Pseudorandomness from Hardness

Existing proofs that deduce BPP = P from circuit lower bounds convert randomized algorithms into deterministic algorithms with a large polynomial slowdown. We convert randomized algorithms into deterministic ones with little slowdown . Specifically, assuming exponential lower bounds against randomized NP ∩ coNP circuits, formally known as randomized SVN circuits, we convert any randomized algorithm over inputs of length n running in time t ≥ n into a deterministic one running in time t 2+α for an arbitrarily small constant α > 0. Such a slowdown is nearly optimal for t close to n , since under standard complexity-theoretic assumptions, there are problems with an inherent quadratic derandomization slowdown. We also convert any randomized algorithm that errs rarely into a deterministic algorithm having a similar running time (with pre-processing). The latter derandomization result holds under weaker assumptions, of exponential lower bounds against deterministic SVN circuits. Our results follow from a new, nearly optimal, explicit pseudorandom generator fooling circuits of size s with seed length (1+α)log s , under the assumption that there exists a function f ∈ E that requires randomized SVN circuits of size at least 2 (1-α′) n , where α = O (α)′. The construction uses, among other ideas, a new connection between pseudoentropy generators and locally list recoverable codes.

Blockchain-based trust mechanism for digital twin empowered Industrial Internet of Things

Emerging technologies such as blockchain and digital twins are essential for the rapid development and employment in Industry 5.0 revolution. With the growing number of industrial IoT nodes, optimizing the network and availing of limited resources to enable secure transmission is difficult. A digital twin is the virtual representation of a physical device that completely depends on sensor data for the critical decision-making simulation process. To this end, we combine a blockchain-based distributed network with a digital twin for the Industrial Internet of Things (IIoT) applications. This paper proposes a blockchain-based Proof of Authority (PoA) trust mechanism to provide high-quality services such as security and data privacy in IIoT. Furthermore, to enhance the authority of decentralized digital twin combined blockchain networks, we introduce a Deterministic Pseudo-Random Generation (DPRG) to generate a genesis block. To evaluate the trustworthiness of the proposed system, we simulate the blockchain network with a digital twin using IIoT sensor nodes. The simulation result shows that the PoA-based authority master nodes can reduce energy consumption and enhance data security.

A Novel Nonlinear Pseudorandom Sequence Generator for the Fractal Function

A pseudorandom sequence is a repeatable sequence with random statistical properties that is widely used in communication encryption, authentication and channel coding. The pseudorandom sequence generator based on the linear feedback shift register has the problem of a fixed sequence, which is easily tracked. Existing methods use the secret linear feedback shift register (LFSR) and built-in multiple LFSRs and is difficult to prevent cracking based on the hardware analysis. Since the plaintext depends on a specific language to be generated, using pseudo-random sequence encryption, it faces the problem that the encryptor cannot hide the characteristics of the plaintext data. Fractal functions have the following properties: chaotic, unpredictable and random. We propose a novel pseudorandom sequence generator based on the nonlinear chaotic systems, which is constructed by the fractal function. Furthermore, we design a data processing matrix to hide the data characteristics of the sequence and enhance the randomness. In the experiment, the pseudo-random sequences generator passed 16 rigorous test items from the National Institute of Standards and Technology (NIST), which means that the nonlinear pseudorandom sequence generator for the fractal function is effective and efficient.

On the algebraic immunity of direct sum constructions

In this paper, we study sufficient conditions to improve the lower bound on the algebraic immunity of a direct sum of Boolean functions. We exhibit three properties on the component functions such that satisfying one of them is sufficient to ensure that the algebraic immunity of their direct sum exceeds the maximum of their algebraic immunities. These properties can be checked while computing the algebraic immunity and they allow to determine better the security provided by functions central in different cryptographic constructions such as stream ciphers, pseudorandom generators, and weak pseudorandom functions. We provide examples for each property and determine the exact algebraic immunity of candidate constructions.

Hardware Efficient Hybrid Pseudo-Random Bit Generator Using Coupled-LCG and Multistage LFSR with Clock Gating Network

A new method for the generation of pseudo-random bits, based on a coupled-linear congruential generator (CLCG) and two multistage variable seeds linear feedback shift registers (LFSRs) is presented. The proposed algorithm dynamically changes the value of the seeds of each linear congruential generator (LCG) by utilizing the multistage variable seeds LFSR. The proposed approach exhibits several advantages over the pseudo-random bit generator (PRBG) methods presented in the literature. It provides low hardware complexity and high-security strength while maintaining the minimum critical path delay. Moreover, this design generates the maximum length of pseudo-random bit sequence with uniform clock latency. Furthermore, to improve the critical path delay, one more architecture of PRBG is proposed in this work. It is based on the combination of coupled modified-LCG with two variable seeds multistage LFSRs. The modified LCG block is designed by the two-operand modulo adder and XOR gate, rather than the three-operands modulo adder and shifting operation, while it maintains the same security strength. The clock gating network (CGN) is also used in this work to minimize the dynamic power dissipation of the overall PRBG architecture. The proposed architectures are implemented using Verilog HDL and further prototyped on commercially available field-programmable gate array (FPGA) devices Virtex-5 and Virtex-7. The realization of the proposed architecture in this FPGA device accomplishes an improved speed of PRBG, which consumes low power with high randomness compared to existing techniques. The generated binary sequence from the proposed algorithms has been verified for randomness tests using NIST statistical test suites.

Comparative evaluation of optical amplifiers in passive optical access networks

In this paper, the parameters of optical amplifiers are evaluated using numerical methods with the Optisystem software. The main objective of this evaluation is the implementation of an optical telecommunication architecture, able to push back the current limits, due to a more and more restricted bandwidth following a demand which does not stop growing. We start from a study of the classical architecture of an optical telecommunication network with an external modulation provided by the mach zehnder modulator, the non return to zero (NRZ) coding, a pseudo random bit generator and a continuous wave (CW) laser diode of frequency 193.1 THz. The results obtained show a transmission possibility at 30.8 dBm and an output power of 25 dBm (316 mW) with an electrical rate signal to noise (SNR) and optical rate signal to noise (OSNR) beyond 34 dBm. The successive integration of the different amplifiers will improve these results with a gain of more than 10 dBm and also provide a better signal quality.

DHSA: efficient doubly homomorphic secure aggregation for cross-silo federated learning

Secure aggregation is widely used in horizontal federated learning (FL), to prevent the leakage of training data when model updates from data owners are aggregated. Secure aggregation protocols based on homomorphic encryption (HE) have been utilized in industrial cross-silo FL systems, one of the settings involved with privacy-sensitive organizations such as financial or medical, presenting more stringent requirements on privacy security. However, existing HE-based solutions have limitations in efficiency and security guarantees against colluding adversaries without a Trust Third Party. This paper proposes an efficient Doubly Homomorphic Secure Aggregation (DHSA) scheme for cross-silo FL, which utilizes multi-key homomorphic encryption (MKHE) and seed homomorphic pseudorandom generator (SHPRG) as cryptographic primitives. The application of MKHE provides strong security guarantees against up to \(N-2\) participates colluding with the aggregator, with no TTP required. To mitigate the large computation and communication cost of MKHE, we leverage the homomorphic property of SHPRG to replace the majority of MKHE computation by computationally friendly mask generation from SHPRG, while preserving the security. Overall, the resulting scheme satisfies the stringent security requirements of typical cross-silo FL scenarios, at the same time providing high computation and communication efficiency for practical usage. We experimentally demonstrate that our scheme brings a speedup to 20\(\times \) over the state-of-the-art HE-based secure aggregation and reduces the traffic volume to approximately 1.5\(\times \) inflation over the plain learning setting.

A pseudo-random bit generator based on chaotic maps enhanced with a bit-XOR operation

Owing to their applications in cryptography, pseudo-random number generators and Pseudo-Random Bit Generators (PRBG) have played an important role in the computer age and their importance is expected to grow exponentially in the coming decades. The chaos phenomenon is commonly used as an entropy source due to its peculiar properties like sensitivity to initial conditions and ergodicity. With emphasis on simplicity of implementation, the present work proposes a simple and novel enhancement to the simple chaotic maps which are otherwise found inadequate to serve the high end requirements of cryptography. The enhancement is based on introducing further randomization of the chaotic map based sequence by implementing a simple XOR operation among the bits of the mantissa of a number constituting the sequence. With this simple XOR operation, simple chaotic maps like the 1-dimensional logistic map and the 2-dimensional Henon map are found to exhibit highly chaotic behaviour over a wide range of their system parameters. A wide range of experiments are conducted to demonstrate and characterize the resulting chaotic maps. The enhanced 2D Henon map is, then, used to implement a PRBG. The PRBG is verified against a wide range statistical parameters and tests. The simplicity of the proposed approach makes it applicable on a wide range of software and hardware platforms.

Chaotification of One-Dimensional Maps Based on Remainder Operator Addition

In this work, a chaotification technique is proposed that can be used to enhance the complexity of any one-dimensional map by adding the remainder operator to it. It is shown that by an appropriate parameter choice, the resulting map can achieve a higher Lyapunov exponent compared to its seed map, and all periodic orbits of any period will be unstable, leading to robust chaos. The technique is tested on several maps from the literature, yielding increased chaotic behavior in all cases, as indicated by comparison of the bifurcation and Lyapunov exponent diagrams of the original and resulting maps. Moreover, the effect of the proposed technique in the problem of pseudo-random bit generation is studied. Using a standard bit generation technique, it is shown that the proposed maps demonstrate increased statistical randomness compared to their seed ones, when used as a source for the bit generator. This study illustrates that the proposed method is an efficient chaotification technique for maps that can be used in chaos-based encryption and other relevant applications.

Image Encryption Algorithm Using 2-Order Bit Compass Coding and Chaotic Mapping

This paper proposes a novel image encryption algorithm based on an integer form of chaotic mapping and 2-order bit compass diffusion technique. Chaotic mapping has been widely used in image encryption. If the floating-point number generated by chaotic mapping is applied to image encryption algorithm, it will slow encryption and increase the difficulty of hardware implementation. An innovative pseudo-random integer sequence generator is proposed. In chaotic system, the result of one-iteration is used as the shift value of two binary sequences, the original symmetry relationship is changed, and then XOR operation is performed to generate a new binary sequence. Multiple iterations can generate pseudo-random integer sequences. Here integer sequences have been used in scrambling of pixel positions. Meanwhile, this paper demonstrates that there is an inverse operation in the XOR operation of two binary sequences. A new pixel diffusion technique based on bit compass coding is proposed. The key vector of the algorithm comes from the original image and is hidden by image encryption. The efficiency of our proposed method in encrypting a large number of images is evaluated using security analysis and time complexity. The performance evaluation of algorithm includes key space, histogram differential attacks, gray value distribution(GDV),correlation coefficient, PSNR, entropy, and sensitivity. The comparison between the results of coefficient, entropy, PSNR, GDV, and time complexity further proves the effectiveness of the algorithm.

Microring resonator-based all-optical parallel pseudo random binary sequence generator for rate multiplication.

In this paper, we design an all-optical Pseudo Random Binary Sequence (PRBS) generator in parallel configuration for operating rate multiplication purposes. The sequential circuit comprises of several clocked D flip-flops, XOR gates and multiplexers implemented using microring resonator (MRR)-based switches. The proposed design is demonstrated and validated through simulations for 500 Gb/s and 400 Gb/s rate doubling and quadrupling, respectively, of a 5-bit degree PRBS. The MRR critical operating parameters are also optimized against performance metrics through numerical investigation.

Mathematical Solution of ULTE Based Salt Generation Password Based Key Derivation Function (PBKDF)

In modern life, users use the cloud spaces for storing important data and valuable information. To avoid security problems, every cloud storage provider requires help from several security mechanisms. Every mechanism has its own security scheme. Most of them use the PBKDF (Password-Based Key Derivation Function) and Salt for generating encryption keys. By analyzing, we found that unique and random Salt plays a vital role for generating keys. But to create powerful keys, we must avoid pseudorandom generators for making salt because hackers can easily crack the key by using it. We have to take inputs from beyond expected sources. We proposed an algorithm by which we can generate Salt by using the client’s real-time environmental information known as Location Information of user, User Time Information with Entropy Data at key generation time. In this paper, we focus on simulation result and compare each algorithm with the proposed algorithm ULTE. Simulation result represents the whole statistical distribution as stated in the algorithm. The result shows that ULTE has provided excellent performance than other algorithms.