28 citations · 100 across the 23 of their papers we have counts for
19 papers · 1 filter
Characterisation of observability and controllability for nonuniformly sampled discrete systems
Amparo Fúster-Sabater, J. M. Guillén
A joint characterisation of the observability and controllability of a particular kind of discrete system has been developed. The key idea of the procedure can be reduced to a corr…
An External Description for MIMO Systems Sampled in an Aperiodic Way
Amparo Fúster-Sabater
An external description for aperiodically sampled MIMO linear systems has been developed. Emphasis is on the sampling period sequence, included among the variables to be handled. T…
New modelling technique for aperiodic-sampling linear systems
Amparo Fúster-Sabater, J. M. Guillén
A general input-output modelling technique for aperiodic-sampling linear systems has been developed. The procedure describes the dynamics of the system and includes the sequence of…
Questions of controllability and observability for nonuniformly sampled discrete systems
Amparo Fúster-Sabater, J. M. Guillén
A joint characterisation of the controllability and observability of a particular kind of discrete system has been developed. The key idea of the procedure can be reduced to a corr…
Simple Cellular Automata-Based Linear Models for the Shrinking Generator
Amparo Fúster-Sabater, Dolores de la Gu'\ia-Martínez
Structural properties of two well-known families of keystream generators, Shrinking Generators and Cellular Automata, have been analyzed. Emphasis is on the equivalence of the bina…
Correction to "Generalized Self-Shrinking Generator"
Amparo Fúster-Sabater
In this correspondence, it is given a correction to Theorem 4 in Y. Hu, and G. Xiao, "Generalized Self-Shrinking Generator," IEEE Transactions on Information Theory, vol. 50, No. 4…
Using Linear Difference Equations to Model Nonlinear Cryptographic Sequences
P. Caballero-Gil, A. Fúster-Sabater, M. E. Pazo-Robles
A new class of linear sequence generators based on cellular automata is here introduced in order to model several nonlinear keystream generators with practical applications in symm…
A Joint Criterion for Reachability and Observability of Nonuniformly Sampled Discrete Systems
Amparo Fúster-Sabater
A joint characterization of reachability (controllability) and observability (constructibility) for linear SISO nonuniformly sampled discrete systems is presented. The work general…
Cellular Automata in Stream Ciphers
Amparo Fúster-Sabater
A wide family of nonlinear sequence generators, the so-called clock-controlled shrinking generators, has been analyzed and identified with a subset of linear cellular automata. The…
Modelling Nonlinear Sequence Generators in terms of Linear Cellular Automata
Amparo Fúster-Sabater, Dolores de la Guía-Martínez
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…
A Simple Computational Model for Acceptance/Rejection of Binary Sequence Generators
Amparo Fúster-Sabater, Pedro García-Mochales
A simple binary model to compute the degree of balancedness in the output sequence of LFSR-combinational generators has been developed. The computational method is based exclusivel…
Likelihood that a pseudorandom sequence generator has optimal properties
Amparo Fúster-Sabater, L. J. García-Villalba
The authors prove that the probability of choosing a nonlinear filter of m-sequences with optimal properties, that is, maximum period and maximum linear complexity, tends assymptot…
On the Use of Cellular Automata in Symmetric Cryptography
Amparo Fuster-Sabater, Pino Caballero-Gil
In this work, pseudorandom sequence generators based on finite fields have been analyzed from the point of view of their cryptographic application. In fact, a class of nonlinear se…
A Simple Attack on Some Clock-Controlled Generators
P. Caballero-Gil, A. Fúster-Sabater
We present a new approach to edit distance attacks on certain clock-controlled generators, which applies basic concepts of Graph Theory to simplify the search trees of the original…
New Attack Strategy for the Shrinking Generator
Pino Caballero-Gil, Amparo Fúster-Sabater, M. Eugenia Pazo-Robles
This work shows that the cryptanalysis of the shrinking generator requires fewer intercepted bits than what indicated by the linear complexity. Indeed, whereas the linear complexit…
Linear Cellular Automata as Discrete Models for Generating Cryptographic Sequences
Pino Caballero-Gil, Amparo Fúster-Sabater, Oscar Delgado-Mohatar
In this paper, we develop a new cellular automata-based linear model for several nonlinear pseudorandom number generators with practical applications in symmetric cryptography. Suc…
Linear solutions for cryptographic nonlinear sequence generators
A. Fúster-Sabater, P. Caballero-Gil
This letter shows that linear Cellular Automata based on rules 90/150 generate all the solutions of linear difference equations with binary constant coefficients. Some of these sol…
On the Design of Cryptographic Primitives
Pino Caballero-Gil, Amparo Fúster-Sabater
The main objective of this work is twofold. On the one hand, it gives a brief overview of the area of two-party cryptographic protocols. On the other hand, it proposes new schemes…
Global Linear Complexity Analysis of Filter Keystream Generators
A. Fúster-Sabater, P. Caballero-Gil
An efficient algorithm for computing lower bounds on the global linear complexity of nonlinearly filtered PN-sequences is presented. The technique here developed is based exclusive…