Ascensión Hernández Encinas

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In this paper we propose a new graphic symmetrical cryp-tosystem in order to encrypt a colored image defined by pixels and by any number of colors. This cryptosystem is based on a reversible bidi-mensional cellular automaton and uses a pseudorandom bit generator. As the key of the cryptosystem is the seed of the pseudorandom bit generator, the latter has to(More)
The cryptographic use of Wolfram cellular automata as pseudoran-dom bit generators and their properties, are presented. After to apply several statistical tests with cryptographic significance and the linear complexity test to these cellular automata, a classification of them is given. Moreover, a crypt-analytic attack to the sequences generated by the(More)
Winter precipitation variability over the Iberian peninsula was investigated by obtaining the spatial and temporal patterns. Empirical Orthogonal Functions were used to describe the variance distribution and to compress the precipitation data into a few modes. The corresponding spatial patterns divide the peninsula into climatic regions according to(More)
The present work exposes a new protocol of electronic voting based on the bit operation XOR and the use of blind signatures. Specifically it is an algorithm designed expressly for the case in which is necessary to choose between two candidates or two options. It is shown that the proposed algorithm satisfies the more important requirements of any e-voting(More)