Quadratic Maps in Two Variables on Arbitrary Fields

Let $\mathbb{F}$ be a field of characteristic different from $2$ and $3$, and let $V$ be a vector space of dimension $2$ over $\mathbb{F}$. The generic classification of homogeneous quadratic maps $f\colon V\to V$ under the action of the linear group of $V$, is given and efficient computational criteria to recognize equivalence are provided.Comment: 12 pages, no figure

Graphic cryptography with pseudorandom bit generators and cellular automata

In this paper we propose a new graphic symmetrical cryptosystem in order to encrypt a colored image defined by pixels and by any number of colors. This cryptosystem is based on a reversible bidimensional 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 be cryptographically secure. Moreover, the recovered image from the ciphered image has not loss of resolution and the ratio between the ciphered image and the original one, i.e., the factor expansion of the cryptosystem, is $1$.Peer reviewe

Graphic cryptosystem using memory cellular automata

In this paper, a new graphic cryptosystem based on reversible memory cellular automata is introduced. Its main feature is that the original image and the cipher image are defined by the same palette of colors and that the recovered image is equal to the original one, that is, there is not loss of resolution. Moreover, it is proved that the proposed cryptosystem is secure against brute-force attacks, statistical attacks and chosen plaintext attacksPeer reviewe

Biometric Fuzzy Extractor Scheme for Iris Templates

In: The 2009 World Congress in Computer Science, Computer Engineering, and Applied Computing (WORLDCOMP'09), The 2009 International Conference on Security and Management (SAM'09), Vol II, Proceedings 563--569. H.R. Arabnia and K. Daimi (Eds.), Las Vegas (USA), July, 2009Biometric recognition offers a reliable and natural solution to the problem of user authentication by means of her physical and behavioral traits. An iris template protection scheme which associates and retrieves a secret value with a high level of security, is proposed. The security is guaranteed thanks to the requirements of fuzzy extractors. The implementation of the scheme is done in Java and experimental results are performed to calculate its False Acceptance Rate and its False Rejection Rate.This work has been partially supported by Ministerio de Industria, Turismo y Comercio (Spain), in collaboration with CDTI and Telefónica I+D under the project SEGUR@ (CENIT-2007 2004).Peer reviewe

ECC programming in Java Card

9 páginas, 3 figuras, 3 listingElliptic Curve Cryptography (ECC) is a branch of public-key cryptography based on the arithmetic of el- liptic curves. Given its mathematical characteristics, ECC is currently one of the best options for protecting sensitive information. The lastest version of the Java Card platform includes several classes related to elliptic curves. However, potential developers are discouraged by the peculiarities of its programming model and the scarce information available. In this work, we present an up to date and extensive review of the ECC support in Java Card. In addition to that, we offer to the reader the complete code of two applications that will allow programmers to understand and test the entire application development process in Java Card.This work has been partially supported by Ministerio de Ciencia e Innovaci ́ on (Spain) under the grant TIN2011- 22668.Peer reviewe

Codificación de información mediante códigos de barras

Se presentan en este artículo varios sistemas de codificación de información mediante códigos de barras. En particular se detalla la forma de elaborar el código de barras EAN13, posiblemente el más utilizado en la actualidad, y su relación con otro de los códigos más empleados: el ISBN para la catalogación de libros. Se incluyen y comentan los procesos matemáticos empleados para elaborar tales códigosPeer reviewe

A New Edit Distance for Fuzzy Hashing Applications

7 páginas, 5 tablas, 2 algoritmos. Comunicación presentada en: The 2015 World Congress in Computer Science, Computer Engineering, and Applied Computing (WORLDCOMP'15). The 2015 International Conference on Security and Management (SAM'15), Las Vegas, USA, July 27 - 30Similarity preserving hashing applications, also known as fuzzy hashing functions, help to analyse the content of digital devices by performing a resemblance comparison between different files. In practice, the similarity matching procedure is a two-step process, where first a signature associated to the files under comparison is generated, and then a comparison of the signatures themselves is performed. Even though ssdeep is the best-known application in this field, the edit distance algorithm that ssdeep uses for performing the signature comparison is not well-suited for certain scenarios. In this contribution we present a new edit distance algorithm that better reflects the similarity of two strings, and that can be used by fuzzy hashing applications in order to improve their results.This work has been partially supported by Comunidad de Madrid (Spain) under the project S2013/ICE-3095-CM (CIBERDINE) and by Ministerio de Economía y Com- petitividad (Spain) under the grant TIN2014-55325-C2-1-R (ProCriCiS).Peer reviewe

Duero Nórdico: la actitud Nórdica en la arquitectura de los Poblados Hidroeléctricos del Douro Internacional (1954-1965)

The construction of reservoirs over the 20th century has allowed for architecture  to play an active role in the duly auxiliary projects, many times using a most definite rationalist language. Just as the Tennessee Valley Authority did, who hired architect Roland A. Wank to design a new city next to the Norris Dam, a team of young architects from Porto (followers of the new trends lead by Le Corbusier or Gropius, but at the same time close to the lyrical values of a border landscape dyed with melancholy) were appointed to designed several linked hydroelectric complexes in the most depressed areas of Portugal in the 50s, bearing in mind the importance  of the location due to its natural value; the culture as a value in itself and the convoluted conditioning context of the proposal. This positioning, which would find in the northern reference its happiest manifestation as from the publication of several essays in Portuguese by Aalto, translates today as an architectonic landscape of omnipresent strength, and its example set in the hydroelectric complexes of Miranda do Douro, Picote or Bemposta is applicable to Saucelle or Aldeadavila, their authorship being entirely SpanishLa construcción de embalses a lo largo del s. XX ha permitido la participación activa de la arquitectura en los proyectos auxiliares que los acompañan, haciendo uso en numerosas ocasiones de un lenguaje decididamente racionalista. A la manera de la Thenessee Valley Authority, que contrató al arquitecto Roland A. Wank para diseñar una nueva ciudad junto al embalse Norris, un equipo de jóvenes arquitectos de Opor- to (adheridos a las nuevas corrientes encabezadas por Le Corbusier o Gropius, pero a la vez apegados a los valores líricos de un paisaje fronterizo teñido de melancolía) dieron respuesta al encargo de diseñar varios complejos hidroeléctricos encadenados en la tierra más deprimida del Portugal de los cincuenta, tomando conciencia de la importancia del lugar como valor natural, de la cultura como valor propio y del con- texto condicionante complejo de la propuesta. Este posicionamiento, que encontraría en el referente nórdico su más feliz manifestación a partir de la publicación de varios textos de Aalto en portugués, se traduce hoy en un paisaje arquitectónico de fuerza omnipresente, y su ejemplo en los complejos hidroeléctricos de Miranda do Douro, Picote o Bemposta se hace extensible a Saucelle o Aldeadávila, de autoría netamente español

A Comparison of the Standardized Versions of ECIES

Elliptic Curve Cryptography (ECC) can be used as a tool for encrypting data, creating digital signatures or performing key exchanges. In relation to encryption, the Elliptic Curve Integrated Encryption Scheme (ECIES) is the best known scheme based on ECC, and as such it has been included in several cryptographic standards. In the present work, we provide an extensive review and comparison of the versions of ECIES included in documents from ANSI, IEEE, ISO/IEC, and SECG, highlighting the main differences between them that can prevent implementations of ECIES from being fully interoperable.This work has been partially supported by Ministerio de Ciencia e Innovación (Spain), under the grant TEC2009-13964-C04-02, and Ministerio de Industria, Turismo y Comercio (Spain), in collaboration with CDTI and Telefónica I+D, under the project Segur@ CENIT-2007 2004.Peer reviewe

Cryptanalysis of a novel cryptosystem based on chaotic oscillators and feedback inversion

An analysis of a recently proposed cryptosystem based on chaotic oscillators and feedback inversion is presented. It is shown how the cryptosystem can be broken when Duffing's oscillator is considered. Some implementation problems of the system are also discussed.Comment: 9 pages, 3 figures, latex forma