New Optimal Binary Sequences with Period 4p4p via Interleaving Ding-Helleseth-Lam Sequences

Binary sequences with optimal autocorrelation play important roles in radar, communication, and cryptography. Finding new binary sequences with optimal autocorrelation has been an interesting research topic in sequence design. Ding-Helleseth-Lam sequences are such a class of binary sequences of period $p$, where $p$ is an odd prime with $p\equiv 1(\bmod~4)$. The objective of this letter is to present a construction of binary sequences of period $4p$ via interleaving four suitable Ding-Helleseth-Lam sequences. This construction generates new binary sequences with optimal autocorrelation which can not be produced by earlier ones

Modelling Nonlinear Sequence Generators in terms of Linear Cellular Automata

In this work, a wide family of LFSR-based sequence generators, the so-called Clock-Controlled Shrinking Generators (CCSGs), has been analyzed and identified with a subset of linear Cellular Automata (CA). In fact, a pair of linear models describing the behavior of the CCSGs can be derived. The algorithm that converts a given CCSG into a CA-based linear model is very simple and can be applied to CCSGs in a range of practical interest. The linearity of these cellular models can be advantageously used in two different ways: (a) for the analysis and/or cryptanalysis of the CCSGs and (b) for the reconstruction of the output sequence obtained from this kind of generators.Comment: 15 pages, 0 figure

Trivium vs. Trivium Toy

We present the characteristic and minimal polynomials of the linear algorithms Trivium and Trivium Toy. We show the different cycles and mini-mum lengths obtained. The existence of initial states determining short cycles is verified. Finally, linear Trivium Toy is shown to be as cryptologically secure as the linear Trivium algorithm.III Workshop de Seguridad Informática (WSI)Red de Universidades con Carreras de Informática (RedUNCI

Trivium vs. Trivium Toy

We present the characteristic and minimal polynomials of the linear algorithms Trivium and Trivium Toy. We show the different cycles and mini-mum lengths obtained. The existence of initial states determining short cycles is verified. Finally, linear Trivium Toy is shown to be as cryptologically secure as the linear Trivium algorithm.III Workshop de Seguridad Informática (WSI)Red de Universidades con Carreras de Informática (RedUNCI