A new countermeasure against side-channel attacks based on hardware-software co-design

This paper aims at presenting a new countermeasure against Side-Channel Analysis (SCA) attacks, whose implementation is based on a hardware-software co-design. The hardware architecture consists of a microprocessor, which executes the algorithm using a false key, and a coprocessor that performs several operations that are necessary to retrieve the original text that was encrypted with the real key. The coprocessor hardly affects the power consumption of the device, so that any classical attack based on such power consumption would reveal a false key. Additionally, as the operations carried out by the coprocessor are performed in parallel with the microprocessor, the execution time devoted for encrypting a specific text is not affected by the proposed countermeasure. In order to verify the correctness of our proposal, the system was implemented on a Virtex 5 FPGA. Different SCA attacks were performed on several functions of AES algorithm. Experimental results show in all cases that the system is effectively protected by revealing a false encryption key.Peer ReviewedPreprin

Hardware architecture implemented on FPGA for protecting cryptographic keys against side-channel attacks

This paper presents a new hardware architecture designed for protecting the key of cryptographic algorithms against attacks by side-channel analysis (SCA). Unlike previous approaches already published, the fortress of the proposed architecture is based on revealing a false key. Such a false key is obtained when the leakage information, related to either the power consumption or the electromagnetic radiation (EM) emitted by the hardware device, is analysed by means of a classical statistical method. In fact, the trace of power consumption (or the EM) does not reveal any significant sign of protection in its behaviour or shape. Experimental results were obtained by using a Virtex 5 FPGA, on which a 128-bit version of the standard AES encryption algorithm was implemented. The architecture could easily be extrapolated to an ASIC device based on standard cell libraries. The system is capable of concealing the real key when various attacks are performed on the AES algorithm, using two statistical methods which are based on correlation, the Welch’s t-test and the difference of means.Peer ReviewedPostprint (author's final draft

The Diffuse Nature of Stromgren Spheres

In this Letter, we argue that the standard analytical derivations of properties of HII regions, such as the speed, shape and asymptotic position of ionisation fronts require a more precise treatment. These derivations use the on the spot approximation, which in effect ignores the diffuse component of the radiation field. We show that, in fact, HII regions are diffusion dominated. This has as a result that the morphology of inhomogeneous HII regions will be drastically different, because shadowing effects have a less profound impact on the apparent shape. Moreover, it will have influence on the propagation speed of ionisation fronts. We quantify our claims by analytically deriving the internal radiation structure of HII regions, taking diffusion fully into account for several different cosmologically relevant density distributions.Comment: 4 pages, 2 figures, accepted for publication in A&A Letter

Análisis del tipo de entidades que colaboran con la Universitat Jaume I

Treball Final de Grau en Mestre o Mestra d'Educació Infantil. Codi: MI1040. Curs acadèmic: 2017/2018En la Universitat Jaume I de Castellón (UJI), a partir del proyecto de investigación EMBI (relaciones universidad-Empresa para docencia, Motivaciones, Beneficio e Impacto) el cual proporciona información sobre los beneficios, impactos y motivaciones de la relación entre la universidad y las entidades del mercado laboral, se ha considerado el siguiente objetivo: obtener información sobre el tipo de entidades que colaboran en las prácticas externas de dicha universidad, teniendo en cuenta su sector académico principalmente. En segundo lugar, se han obtenido resultados sobre la titularidad y sobre el tamaño de estas mismas entidades. Esta información se ha obtenido mediante entrevistas, encuestas y también a partir de una base de datos facilitada por la UJI. Para adquirir dicha información se ha realizado un análisis cuantitativo y un análisis de frecuencias hecho a partir de las muestras y clasificando las entidades según el sector académico: Artes y Humanidades; Salud; Sociales y Jurídicas; Ingeniería y Arquitectura; otros. Por tanto, en este artículo podemos descubrir el contraste entre los porcentajes de las diferentes modalidades según el sector académico principalmente, y los porcentajes de titularidad y tamaño. Se tiene en cuenta que las entidades que se han encontrado en la base de datos son tanto nacionales como internacionales y, además, actualmente están colaborando con la universidad en todo lo referente al diseño, desarrollo e impartición de los planes. Como conclusión, se ha obtenido un porcentaje elevado de entidades que se dedican al sector Social y Jurídico, y en lo referente a la titularidad y al tamaño, el porcentaje alto es para la titularidad privada y las micro empresas.At the Universitat Jaume I de Castellón (UJI), based on the research project EMBI (UniversityCompany relations for teaching, Motivations, Benefit and Impact), which provides information about the benefits, impacts and motivations of the relationship between the university and the entities of the labour market, the following objective has been considered: to obtain information about the type of entities that collaborate in the external practices of said university, mainly taking into account its academic sector. Secondly, results have been obtained on the ownership and size of these same entities. This information has been obtained through interviews, surveys and also from a database provided by the UJI. In order to acquire this information, a quantitative analysis and a frequency analysis has been carried out, based on the samples and classifying the companies according to the academic sector: Arts and Humanities; Health; Social and Legal; Engineering and Architecture; others. Therefore, in this article we can discover the contrast between the percentages of the different modalities according to the academic sector mainly, and the percentages of ownership and size. It is taken into account that the entities that have been found in the database are both national and international and, in addition, are currently collaborating with the university in everything related to the design, development and delivery of the plans. In conclusion, a high percentage of entities dedicated to the social and legal sector have been obtained, and in terms of ownership and size, the high percentage is for private ownership and micro enterprises

Biotecnología de microalgas. Producción de biodiésel

Debido a la situación planteada actualmente como consecuencia del agotamiento de los combustibles fósiles, el aumento del precio del petróleo o la creciente preocupación ambiental, se demanda urgentemente la búsqueda de fuentes de energía alternativas basadas en procesos sostenibles, renovables y respetuosos con el medio ambiente. En este contexto, la producción de biodiésel resulta ser una de las alternativas que ofrece mejores expectativas. Durante este trabajo se revisan las vías existentes para la producción de biodiésel por transesterificación catalítica. Además se tratará de llevar a cabo el diseño y evaluación de la propuesta de instalación de una planta para producción de biodiesel a partir de la transesterificación de aceites procedentes de la microalga Nannochloropsis en un medio con catalizador ácido (ácido sulfúrico 98%) mediante el uso del simulador Super Pro Designer. Se abordará la evaluación de diversos aspectos económicos del proceso con el fin de determinar la rentabilidad del mismo bajo distintas condiciones

Michel Wieviorka: La primavera de la política. Ideas para acabar con el declive de la democracia tradicional. Vanguardia, Barcelona, 2007

Sin resume

Pulsed light inactivation of mushroom polyphenol oxidase: a fluorometric and spectrophotometric study

Polyphenol oxidase (PPO) is one of the most important food enzymes, it is responsible for the browning of many foods. Pulsed light (PL) is a non-thermal method of food preservation that is able to inactivate PPO. The aim of this work was to gain insight into the mechanism of PPO inactivation by PL. To this, the kinetics of PPO inactivation by PL was measured, together with associated changes in tryptophan fluorescence, KI fluorescence quenching and turbidity; and results were analysed by parameter A and phase diagram methods. Enzyme inactivation followed the Weibull model. Tryptophan fluorescence decreased during PL treatment, as well as the parameter A, while Stern-Volmer constants increased and turbidity was constant. The phase diagram showed only two populated states. There was a high correlation between the loss of activity and parameter A. Results indicate that under the experimental conditions, the inactivation of PPO by PL is an all-or-none process where the enzyme progressively unfolds with no evidence of aggregation.Fundación Universitaria San Antonio de CartagenaCiencias de la Alimentació