Nonlinear Pseudorandom Sequences Research Articles

Method for the Simultaneous Generation of Two Nonlinear Pseudo Random Sequences: 5-ary and Binary

Multi-level signals and sequences have become a significant aspect of modern high-speed communication systems. Hence, to ensure the confidentiality and integrity of the transmitted information, advanced methods and devices are necessary to produce strong cryptographic properties for not only binary but also for nonbinary keystreams, which can be used in resource-constrained microcontrollers. The proposed method and apparatus generate both a balanced nonlinear 5-ary pseudo-random sequence and a binary keystream sequence. The nonlinearity is determined by applying shrinking and multiplexing techniques to the generated linear 5-ary pseudo-random sequence and the running zero in its conversion to a binary balanced sequence.

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.

ВАРИАНТ АЛГОРИТМА ГЕНЕРАЦИИ ПСЕВДОСЛУЧАЙНЫХ ДВОИЧНЫХ ПОСЛЕДОВАТЕЛЬНОСТЕЙ, ОСНОВАННЫЙ НА СВОЙСТВАХ ЛИНЕЙНЫХ КЛЕТОЧНЫХ АВТОМАТОВ

The article is devoted to the development of a linear system for generating a pseudo-random sequence based on cellular automata, the development of a model for several generators of nonlinear pseudo-random sequences with practical applications in symmetric data transformation systems. Such a model generates all solutions to linear binary difference equations. It is important to note that many of these solutions are pseudo-random keystream sequences. In the process of developing a linear system based on cellular automata, two main structures are considered: linear difference equations and one-dimensional linear hybrid cellular automata. This article shows that all solutions to linear binary difference equations can be implemented using linear models based on cellular automata using the "rule 90" and "rule 150". A model for generating pseudo-random bit sequences has been developed, which is most applicable in communication systems with a high transmission rate. The main difference of this model is that it is built on an exclusively sequential concatenation of a basic linear automaton, which determines the simplicity of the proposed model. Also, an algorithm for controlling the integrity and authenticity of block data was proposed based on the proposed algorithm for generating a pseudo-random sequence. The practical significance lies in the fact that the proposed model is simple and can be applied in information security systems in practice, including in authentication and data integrity control systems.

A Novel Self-Embedding Watermarking Scheme for Image Tamper Detection and Recovery

In this paper, an effective self-embedding fragile watermarking scheme is proposed. The watermark is generated by encoding the DCT coefficients of each 2×2 block and embedded into another block. A non-linear pseudo random sequence is used for generating the block mapping which can enhance the security of the algorithm. An improved tamper localization and recovery algorithm are performed. The experiment results show that the tamper region can be successfully localized and exactly recovered, even if under the content-only tampering.

A Research Development in Autocorrelation of Nonlinear Pseudorandom Sequences

Nonlinear continuous value sequences have been widely used as pseudorandom sequences, but their autocorrelation rules make us puzzled. Yet the nonlinear continuous value sequences are neither same as the well known binary sequences, nor same as the well known noise sequences. So we have to find other effective methods to study the autocorrelation rules of nonlinear sequence. In this paper, we introduced a phase space method to study their autocorrelation rules, and some simple yet effective conclusions were reached to assess and improve their autocorrelation performances. Many simulations were presented, too.

On k-error linear complexity of some explicit nonlinear pseudorandom sequences

Combining with the research on the linear complexity of explicit nonlinear generators of pseudorandom sequences, we study the stability on linear complexity of two classes of explicit inversive generators and two classes of explicit nonlinear generators. We present some lower bounds in theory on the k-error linear complexity of these explicit generators, which further improve the cryptographic properties of the corresponding number generators and provide very useful information when they are applied to cryptography.