Parabolic equations with nonlocal boundary conditions have been given considerable attention in r... more Parabolic equations with nonlocal boundary conditions have been given considerable attention in recent years. In this paper new high-order algorithms for the linear diffusion-reaction problem are derived. The convergence of the new schemes is studied and numerical examples are given to show the efficiency of the new methods to solve linear and nonlinear diffusion-reaction equations with these non classical conditions.
The security in current communications recommend to develop the implementation of cryptographic p... more The security in current communications recommend to develop the implementation of cryptographic primitives and algorithms in an effective way. The cryptosystem proposed by Chor and Rivest, which is based on the knapsack problem, has recently been broken by Vaudenay but only when the original parameters are used. In this paper we give a brief overview of some developments in Cryptography and we present a safe implementation for Chor-Rivest Cryptosystem by using Magma software.
2014 9th Iberian Conference on Information Systems and Technologies (CISTI), 2014
ABSTRACT Universities today offer many courses where the study materials can be obtained online t... more ABSTRACT Universities today offer many courses where the study materials can be obtained online through different mechanisms. The terms e-learning and b-learning are being overshadowed by u-learning (ubiquitous learning), since the learning scenario is any place and any device that can be used to get the materials. The task of preparing the appropriate materials in this new context cannot be addressed individually and, consequently, international collaborative process can be very fruitful. The main goal is to adapt the study materials for using in several Universities, with official recognition for any University involved in the collaborative process and with agreements with other Universities interested in the use of such materials. We will present an ongoing experience which involves the National Technological University (UTN) in Buenos Aires, Argentina, and Spanish universities: Salamanca University (USAL) and Pontificia Comillas University (UPCOMILLAS) in Madrid. The authors of this paper have updated a virtual Multivariable Calculus course, hosted in the virtual learning environment STUDIUM to be used by the students from the three universities.
In this study a new experience for teaching mathematics to engineering students, is presented. Th... more In this study a new experience for teaching mathematics to engineering students, is presented. The aim is to provide the students a better understanding of maths algorithms and basic concepts by using specific software, in a graduate-level course. In this paper we discuss how to structure, define, and implement a webbased course as a part of the traditional classes, according to the convergence of the European Higher Education Project. The proposed course facilitates the use of new Information and Communication Technologies.
Resumen. En este artículo presentamos un caso práctico de utilización de las TIC para mejorar el ... more Resumen. En este artículo presentamos un caso práctico de utilización de las TIC para mejorar el proceso de enseñanza-aprendizaje de la asignatura de Economía de la Empresa impartida en la Licenciatura de Administración y Dirección de Empresas en la Universidad de Salamanca. En particular veremos una aplicación concreta del proceso de aprendizaje adaptado al nuevo Espacio Europeo de Educación Superior mediante la utilización de Internet como recurso docente.
43 Fecha de publicación de la solicitud: 01.11.2004 Fecha de la concesión: 28.12.2005 45 Fecha de... more 43 Fecha de publicación de la solicitud: 01.11.2004 Fecha de la concesión: 28.12.2005 45 Fecha de anuncio de la concesión: 01.02.2006 45 Fecha de publicación del folleto de la patente: 01.02.2006 73 Titular/es: Consejo Superior de Investigaciones Científicas c/ Serrano, 117 28006 Madrid, ES Araceli Queiruga Dios 72 Inventor/es: Hernández Encinas, Luis; Muñoz Masque, Jaime y Queiruga Dios, Araceli 74 Agente: No consta 54 Título: Procedimiento y dispositivo de encriptación mediante un criptosistema tipo RSA. 57 Resumen: Procedimiento y dispositivo de encriptación mediante un criptosistema tipo RSA.
... to teach students about the usefulness and importance of the new technologies and what is mor... more ... to teach students about the usefulness and importance of the new technologies and what is more interesting: how to use them in a work ... [8] PA Kirschner, Using integrated electronic environments for collaborative ... Research Dialogue in Learning and Instruction, 2, 1 (2001) 110. ...
Resumen-La seguridad del criptosistema propuesto por Chor y Rivest se basa en el problema matemát... more Resumen-La seguridad del criptosistema propuesto por Chor y Rivest se basa en el problema matemático de la mochila y ha sido roto por Vaudenay, pero sólo cuando se utilizan los parámetros originales propuestos en 1985. En este trabajo se presenta una búsqueda exhaustiva de nuevos parámetros a los que no son aplicables los criptoanálisis conocidos, incluido el de Vaudenay. Tales parámetros seguros se han utilizado para desarrollar una implementación eficiente del criptosistema de Chor-Rivest con el software Magma.
Digital signature, as an official signature, have many applications in information security, incl... more Digital signature, as an official signature, have many applications in information security, including authentication, data integrity, and non-repudiation. When a private or public document must be signed by a group of people, we call it multisignature scheme if all and every single member of the group signs the document.
To date, several cryptographic protocols for images have been proposed, but in general, the recov... more To date, several cryptographic protocols for images have been proposed, but in general, the recovered image is not the same as the original one, which is a problem in several applications like the human identification by means of iris recognition, for example. In this paper, a graphic secret-key cryptosystem for encrypting color images is presented. The cryptosystem is based on a one-dimensional reversible cellular automaton. Moreover, the original and the encrypted image are defined by the same color palette and the decrypted image is identical to the original one, i.e., it has no loss of resolution nor definition in the whole protocol. Furthermore, it is proved that the cryptosystem is safe against brute force and statistical attacks.
In this paper it is shown that two-dimensional cellular automata with Von Neumann neighborhoods a... more In this paper it is shown that two-dimensional cellular automata with Von Neumann neighborhoods are not suitable for cryptographic purposes. This result is obtained after analyzing the most important cryptographic properties of Boolean functions defining their local transition rules.
The most popular encryption scheme based on elliptic curves is the Elliptic Curve Integrated Encr... more The most popular encryption scheme based on elliptic curves is the Elliptic Curve Integrated Encryption Scheme (ECIES), which is included in ANSI X9.63, IEEE 1363a, ISO/IEC 18033-2, and SECG SEC1. These standards offer many ECIES options, not always compatible, making it difficult to decide what parameters and cryptographic elements to use in a specific deployment scenario. In this work, we show that a secure and practical implementation of ECIES can only be compatible with two of the four previously mentioned standards. In addition to that, we provide the list of functions and options that must be used in such an implementation. Finally, we present the results obtained when testing this ECIES version implemented as a Java application, which allows us to produce some comments and remarks about the performance and feasibility of our proposed solution.
A new experience for teaching Cryptography to engineering students is shown. The aim is to give t... more A new experience for teaching Cryptography to engineering students is shown. The aim is to give them a better understanding of secure and cryptographic algorithms by using Maple software, in a graduate-level course. In this paper we discuss how to structure, define, and implement a web-based course as a part of the traditional classes, according to the convergence of the European Higher Education Project. The proposed course facilitates the use of new Information and Communication Technologies.
Parabolic equations with nonlocal boundary conditions have been given considerable attention in r... more Parabolic equations with nonlocal boundary conditions have been given considerable attention in recent years. In this paper new high-order algorithms for the linear diffusion-reaction problem are derived. The convergence of the new schemes is studied and numerical examples are given to show the efficiency of the new methods to solve linear and nonlinear diffusion-reaction equations with these non classical conditions.
The security in current communications recommend to develop the implementation of cryptographic p... more The security in current communications recommend to develop the implementation of cryptographic primitives and algorithms in an effective way. The cryptosystem proposed by Chor and Rivest, which is based on the knapsack problem, has recently been broken by Vaudenay but only when the original parameters are used. In this paper we give a brief overview of some developments in Cryptography and we present a safe implementation for Chor-Rivest Cryptosystem by using Magma software.
2014 9th Iberian Conference on Information Systems and Technologies (CISTI), 2014
ABSTRACT Universities today offer many courses where the study materials can be obtained online t... more ABSTRACT Universities today offer many courses where the study materials can be obtained online through different mechanisms. The terms e-learning and b-learning are being overshadowed by u-learning (ubiquitous learning), since the learning scenario is any place and any device that can be used to get the materials. The task of preparing the appropriate materials in this new context cannot be addressed individually and, consequently, international collaborative process can be very fruitful. The main goal is to adapt the study materials for using in several Universities, with official recognition for any University involved in the collaborative process and with agreements with other Universities interested in the use of such materials. We will present an ongoing experience which involves the National Technological University (UTN) in Buenos Aires, Argentina, and Spanish universities: Salamanca University (USAL) and Pontificia Comillas University (UPCOMILLAS) in Madrid. The authors of this paper have updated a virtual Multivariable Calculus course, hosted in the virtual learning environment STUDIUM to be used by the students from the three universities.
In this study a new experience for teaching mathematics to engineering students, is presented. Th... more In this study a new experience for teaching mathematics to engineering students, is presented. The aim is to provide the students a better understanding of maths algorithms and basic concepts by using specific software, in a graduate-level course. In this paper we discuss how to structure, define, and implement a webbased course as a part of the traditional classes, according to the convergence of the European Higher Education Project. The proposed course facilitates the use of new Information and Communication Technologies.
Resumen. En este artículo presentamos un caso práctico de utilización de las TIC para mejorar el ... more Resumen. En este artículo presentamos un caso práctico de utilización de las TIC para mejorar el proceso de enseñanza-aprendizaje de la asignatura de Economía de la Empresa impartida en la Licenciatura de Administración y Dirección de Empresas en la Universidad de Salamanca. En particular veremos una aplicación concreta del proceso de aprendizaje adaptado al nuevo Espacio Europeo de Educación Superior mediante la utilización de Internet como recurso docente.
43 Fecha de publicación de la solicitud: 01.11.2004 Fecha de la concesión: 28.12.2005 45 Fecha de... more 43 Fecha de publicación de la solicitud: 01.11.2004 Fecha de la concesión: 28.12.2005 45 Fecha de anuncio de la concesión: 01.02.2006 45 Fecha de publicación del folleto de la patente: 01.02.2006 73 Titular/es: Consejo Superior de Investigaciones Científicas c/ Serrano, 117 28006 Madrid, ES Araceli Queiruga Dios 72 Inventor/es: Hernández Encinas, Luis; Muñoz Masque, Jaime y Queiruga Dios, Araceli 74 Agente: No consta 54 Título: Procedimiento y dispositivo de encriptación mediante un criptosistema tipo RSA. 57 Resumen: Procedimiento y dispositivo de encriptación mediante un criptosistema tipo RSA.
... to teach students about the usefulness and importance of the new technologies and what is mor... more ... to teach students about the usefulness and importance of the new technologies and what is more interesting: how to use them in a work ... [8] PA Kirschner, Using integrated electronic environments for collaborative ... Research Dialogue in Learning and Instruction, 2, 1 (2001) 110. ...
Resumen-La seguridad del criptosistema propuesto por Chor y Rivest se basa en el problema matemát... more Resumen-La seguridad del criptosistema propuesto por Chor y Rivest se basa en el problema matemático de la mochila y ha sido roto por Vaudenay, pero sólo cuando se utilizan los parámetros originales propuestos en 1985. En este trabajo se presenta una búsqueda exhaustiva de nuevos parámetros a los que no son aplicables los criptoanálisis conocidos, incluido el de Vaudenay. Tales parámetros seguros se han utilizado para desarrollar una implementación eficiente del criptosistema de Chor-Rivest con el software Magma.
Digital signature, as an official signature, have many applications in information security, incl... more Digital signature, as an official signature, have many applications in information security, including authentication, data integrity, and non-repudiation. When a private or public document must be signed by a group of people, we call it multisignature scheme if all and every single member of the group signs the document.
To date, several cryptographic protocols for images have been proposed, but in general, the recov... more To date, several cryptographic protocols for images have been proposed, but in general, the recovered image is not the same as the original one, which is a problem in several applications like the human identification by means of iris recognition, for example. In this paper, a graphic secret-key cryptosystem for encrypting color images is presented. The cryptosystem is based on a one-dimensional reversible cellular automaton. Moreover, the original and the encrypted image are defined by the same color palette and the decrypted image is identical to the original one, i.e., it has no loss of resolution nor definition in the whole protocol. Furthermore, it is proved that the cryptosystem is safe against brute force and statistical attacks.
In this paper it is shown that two-dimensional cellular automata with Von Neumann neighborhoods a... more In this paper it is shown that two-dimensional cellular automata with Von Neumann neighborhoods are not suitable for cryptographic purposes. This result is obtained after analyzing the most important cryptographic properties of Boolean functions defining their local transition rules.
The most popular encryption scheme based on elliptic curves is the Elliptic Curve Integrated Encr... more The most popular encryption scheme based on elliptic curves is the Elliptic Curve Integrated Encryption Scheme (ECIES), which is included in ANSI X9.63, IEEE 1363a, ISO/IEC 18033-2, and SECG SEC1. These standards offer many ECIES options, not always compatible, making it difficult to decide what parameters and cryptographic elements to use in a specific deployment scenario. In this work, we show that a secure and practical implementation of ECIES can only be compatible with two of the four previously mentioned standards. In addition to that, we provide the list of functions and options that must be used in such an implementation. Finally, we present the results obtained when testing this ECIES version implemented as a Java application, which allows us to produce some comments and remarks about the performance and feasibility of our proposed solution.
A new experience for teaching Cryptography to engineering students is shown. The aim is to give t... more A new experience for teaching Cryptography to engineering students is shown. The aim is to give them a better understanding of secure and cryptographic algorithms by using Maple software, in a graduate-level course. In this paper we discuss how to structure, define, and implement a web-based course as a part of the traditional classes, according to the convergence of the European Higher Education Project. The proposed course facilitates the use of new Information and Communication Technologies.
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