@article {MoLo15, title = {A practical solution for sealed bid and multi-currency auctions}, journal = {Computers \& Security}, volume = {45}, year = {2014}, month = {09/2014}, pages = {186-198}, publisher = {Elsevier}, abstract = {
This paper introduces a sealed bid and multi-currency auction using secure multiparty computation (SMC). 
Two boolean functions, a comparison and multiplication function, have been designed as required to apply SMC. These functions are applied without revealing any information, not even to trusted third parties such as the auctioneer. A type of Zero Knowledge proof, discreet proof, has been implemented with three variants, interactive, regular and reduced non interactive proofs. These proofs make it possible to verify the correctness of the functions whilst preserving the privacy of the bid values. Moreover, a system performance evaluation of the proposal has been realized on heterogeneous platforms, including a mobile platform. The evaluation concludes that our proposal is practical even on mobile platforms.
}, keywords = {Multi-currency auctions, proof certification, Sealed auctions, Secure Multiparty computation, Zero Knowledge Protocols}, issn = {0167-4048}, doi = {10.1016/j.cose.2014.06.004}, author = {Jose A. Montenegro and Javier Lopez} } @article {MFLR13, title = {Secure sealed-bid online auctions using discreet cryptographic proofs}, journal = {Mathematical and Computer Modelling}, volume = {57}, year = {2013}, month = {Jun 2013}, pages = {2583{\textendash}2595}, publisher = {Elsevier}, abstract = {

This work describes the design and implementation of an auction system using secure multiparty computation techniques. Our aim is to produce a system that is practical under actual field constraints on computation, memory, and communication. The underlying protocol is privacy-preserving, that is, the winning bid is determined without information about the losing bids leaking to either the auctioneer or other bidders. Practical implementation of the protocol is feasible using circuit-based cryptographic proofs along with additively homomorphic bit commitment. Moreover, we propose the development of a\ Proof Certificatestandard. These certificates convey sufficient information to recreate the cryptographic proofs and verify them offline.

}, issn = {0895-7177}, doi = {http://dx.doi.org/10.1016/j.mcm.2011.07.027}, author = {Jose A. Montenegro and Michael J. Fischer and Javier Lopez and Rene Peralta} } @inproceedings {JoseA.Montenegro2010, title = {Computacion Segura Multiparte Aplicada a Subastas Electr{\'o}nicas}, booktitle = {IX Jornadas de Ingenier{\'\i}a Telemenatica (JITEL 2010)}, year = {2010}, month = {Octubre}, abstract = {

La confidencialidad ha pasado de ser un requisito de seguridad a ser considerado como requisito funcional y de obligado cumplimiento e inclusi\ón en todos los sistemas de comunicaciones. Un inconveniente que presenta las t\écnicas criptogr\áficas, utilizadas para obtener la confidencialidad de la informaci\ón, surge cuando varias entidades se ven forzadas a compartir informaci\ón secreta para realizar tareas puntuales de colaboraci\ón, ya que las primitivas tradicionales utilizadas para conseguir la confidencialidad resultan poco flexibles. La situaci\ón ideal permitir\ía hacer posible dicha colaboraci\ón sin que ninguna de las partes revele la informaci\ón aportada. En este escenario entra en juego la tecnolog\ía de Computaci\ón Segura Multiparte (CSM) que posibilita realizar operaciones con la informaci\ón compartida sin tener que hacerla p\ública. Este trabajo muestra una soluci\ón CSM aplicada a una subasta electr\ónica que permite la realizaci\ón de la subasta sin que las apuestas sean reveladas a ning\ún participante, incluyendo el subastador, por lo que no necesita el estableciendo de ninguna autoridad confiable. Aunque la literatura ofrece una amplia variedad de propuestas te\óricas de CSM desde su creaci\ón en la d\écada de los ochenta, no es com\ún su aplicacion pr\áctica en situaciones reales.

}, author = {Jose A. Montenegro and Javier Lopez and Rene Peralta} } @article {JordiForne2009, title = {Pervasive Authentication and Authorization Infrastructures for Mobile Users}, journal = {Computer and Security}, volume = {29}, year = {2010}, pages = {501-514}, publisher = {elsevier}, abstract = {

Network and device heterogeneity, nomadic mobility, intermittent connectivity and, more generally, extremely dynamic operating conditions, are major challenges in the design of security infrastructures for pervasive computing. Yet, in a ubiquitous computing environment, limitations of traditional solutions for authentication and authorization can be overcome with a pervasive public key infrastructure (pervasive-PKI). This choice allows the validation of credentials of users roaming between heterogeneous networks, even when global connectivity is lost and some services are temporarily unreachable. Proof-of-concept implementations and testbed validation results demonstrate that strong security can be achieved for users and applications through the combination of traditional PKI services with a number of enhancements like: (i) dynamic and collaborative trust model, (ii) use of attribute certificates for privilege management, and (iii) modular architecture enabling nomadic mobility and enhanced with reconfiguration capabilities.

}, issn = {0167-4048}, doi = {10.1016/j.cose.2009.09.001}, author = {Jordi Forne and Francisca Hinajeros and Andres Marin and Florina Almenarez and Javier Lopez and Jose A. Montenegro and Marc Lacoste and Daniel Diaz} } @article {Agudo2008d, title = {Enabling Attribute Delegation in Ubiquitous Environments}, journal = {Mobile Networks and Applications}, volume = {13}, number = {3-4}, year = {2008}, month = {August}, pages = {398-410}, publisher = {Springer}, abstract = {

When delegation is implemented using the attribute certificates in a Privilege Management Infrastructure (PMI), it is possible to reach a considerable level of distributed functionality. However, the approach is not flexible enough for the requirements of ubiquitous environments. The PMI can become a too complex solution for devices such as smartphones and PDAs, where resources are limited. In this work we present an approach to solve the previous limitations by defining a second class of attributes, called domain attributes, which are managed directly by users and are not right under the scope of the PMI, thus providing a light solution for constrained devices. However, we relate the two classes of attributes are related by defining a simple ontology. While domain attribute credentials are defined using SAML notation, global attributes are defined using X.509 certificates. For this reason, we additionally introduce XSAML so that both kinds of credentials are integrated. We also introduce the concept of Attribute Federation which is responsible for supporting domain attributes and the corresponding ontology.

}, keywords = {attribute based authorization, delegation, federation}, issn = {1383-469X}, doi = {10.1007/s11036-008-0062-4}, author = {Isaac Agudo and Javier Lopez and Jose A. Montenegro} } @inproceedings {Agudo2007a, title = {Attribute delegation in ubiquitous environments}, booktitle = {3rd international conference on Mobile multimedia communications (MobiMedia {\textquoteright}07)}, year = {2007}, pages = {43:1{\textendash}43:6}, publisher = {ICST}, organization = {ICST}, address = {Nafpaktos, Greece}, abstract = {

When delegation is implemented using the attribute certificates in a Privilege Management Infrastructure (PMI), this one reaches a considerable level of distributed functionality. However, the approach is not flexible enough for the requirements of ubiquitous environments. Additionally, the PMI can become a too complex solution for devices such as smartphones and PDAs, where resources are limited. In this work, we solve the previous limitations by defining a second class of attributes, called domain attributes, which are managed directly by users and are not right under the scope of the PMI, thus providing a light solution for constrained devices. The two classes of attributes are related by defining a simple ontology. We also introduce in the paper the concept of Attribute Federation which is responsible for supporting domain attributes and the corresponding ontology.

}, isbn = {978-963-06-2670-5}, author = {Isaac Agudo and Javier Lopez and Jose A. Montenegro} } @article {JavierLopez2007, title = {On the deployment of a real scalable delegation service}, journal = {Information Security Technical Report}, volume = {12}, number = {3}, year = {2007}, month = {Jun 2007}, pages = {139-147}, publisher = {Elsevier}, abstract = {

This paper explains the evolution of the concept of delegation since its first references in the context of distributed authorization to the actual use as a fundamental part of a privilege management architecture. The work reviews some of the earliest contributions that pointed out the relevance of delegation when dealing with distributed authorization, in particular we comment on PolicyMaker and Keynote, and also on SDSI/SPKI. Then, we elaborate on Federation as a particular case of delegation, and remark the importance given to federation by the industry. Finally, the paper discusses about privilege management infrastructures, introducing a new mechanism to extend their functionality using advanced delegation services.

}, issn = {1363-4127}, doi = {10.1016/j.istr.2007.05.008}, author = {Javier Lopez and Isaac Agudo and Jose A. Montenegro} } @incollection {vivas2007, title = {Grid Security Architecture: Requirements, Fundamentals, Standards and Models}, booktitle = {Security in Distributed, Grid, Mobile, and Pervasive Computing}, year = {2007}, month = {April}, pages = {255-288}, publisher = {Auerbach Publications}, organization = {Auerbach Publications}, isbn = {9780849379215}, author = {Jose L. Vivas and Jose A. Montenegro and Javier Lopez}, editor = {Y. Xiao} } @inproceedings {Agudo2007, title = {Implementation aspects of a delegation system}, booktitle = {3rd international conference on Mobile multimedia communications (MobiMedia {\textquoteright}07)}, year = {2007}, pages = {50:1{\textendash}50:6}, publisher = {ICST}, organization = {ICST}, address = {Nafpaktos, Greece}, abstract = {

In this paper we simulate an authorization and delegation system using knowledge based technology. This proposal is part of a visual tool that is intended to be an implementation of the theoretical model weighted trust graph (WTG). A brief description of WTG Model and its associated tool is included in the text. In essence, the model is based on the inclusion of real numbers between zero and one in certificates to represent the trust level between the entities involved in them. This trust level is used to control delegation. Moreover, attributes from di_erent domains may be interrelated, so attribute delegation is also taken into account. The proposed Simulation Engine supports one directional and bidirectional search algorithms.

}, isbn = {978-963-06-2670-5}, author = {Isaac Agudo and Javier Lopez and Jose A. Montenegro} } @inproceedings {IsaacAgudo2006, title = {Attributes Delegation Based on Ontologies and Context Information}, booktitle = {10th IFIP TC-6 TC-11 International Conference on Communications and Multimedia on Security (CMS{\textquoteright}06)}, series = {LNCS}, volume = {4237}, year = {2006}, month = {October}, pages = {54-66}, publisher = {Springer}, organization = {Springer}, address = {Heraklion, Crete}, abstract = {

This paper presents a model for delegation based on partial orders, proposing the subclass relation in OWL as a way to represent the partial orders. Delegation and authorization decisions are made based on the context. In order to interact with the context, we define the Type of a credential as a way to introduce extra information regarding context constraints. When reasoning about delegation and authorization relationships, our model benefits from partial orders, defining them over entities, attributes and the credential type. Using these partial orders, the number of credentials required is reduced. It also classifies the possible criteria for making authorization decisions based on the context, in relation to the necessary information.

}, isbn = {978-3-540-47820-1}, issn = {0302-9743 (Print) 1611-3349 (Online)}, doi = {10.1007/11909033_6}, author = {Isaac Agudo and Javier Lopez and Jose A. Montenegro} } @inproceedings {Agudo2006a, title = {Graphical Representation of Authorization Policies for Weighted Credentials}, booktitle = {11th Australasian Conference on Information Security and Privacy (ACISP{\textquoteright}06)}, series = {LNCS}, volume = {4058}, year = {2006}, pages = {383-394}, publisher = {Springer}, organization = {Springer}, address = {Melbourne, Australia}, abstract = {

This paper elaborates on a solution to represent authorization and delegation in a graphical way, allowing users to better interpret delegation relationships. We make use of Weighted Trust Graph (WTG) as an instrument to represent delegation and authorization, extending it to cope with more complicated concepts, and providing a graphical representation of the level of confidence that exists between two entities regarding a resource or attribute. We represent the level of confidence for each pair of entities as a point in an axis diagram, as a set of points, or as a set of triangular regions depending on the accuracy we need. Then, we use the same diagram to represent the set of acceptable confidence level, that we call authorization policy set. In this way, a single diagram can be used to decide about authorization, thus providing a powerful tool for systems in which interaction of users is needed.

}, isbn = {978-3-540-35458-1}, issn = {0302-9743 (Print) 1611-3349 (Online)}, doi = {10.1007/11780656_32}, author = {Isaac Agudo and Javier Lopez and Jose A. Montenegro} } @inproceedings {IsaacAgudo2006a, title = {Pol{\'\i}ticas de delegaci{\'o}n para credenciales ponderadas y su representaci{\'o}n gr{\'a}fica}, booktitle = {IX Reuni{\'o}n Espa{\~n}ola sobre Criptolog{\'\i}a y Seguridad de la informaci{\'o}n (RECSI{\textquoteright}06)}, year = {2006}, month = {Septiembre}, pages = {311-322}, address = {Barcelona, Spain}, isbn = {84-9788-502-3}, author = {Isaac Agudo and Javier Lopez and Jose A. Montenegro} } @inproceedings {JavierLopez2006a, title = {Service-Oriented Security Architecture for CII based on Sensor Networks}, booktitle = {2nd International Workshop on Security Privacy and Trust in Pervasive and Ubiquitous Computing (SecPerU{\textquoteright}06)}, year = {2006}, month = {June}, pages = {1-6}, publisher = {IEEE Press}, organization = {IEEE Press}, address = {Lyon, France}, abstract = {

The extraordinary growth of the Information Society is originating a high dependency on ICT. This provokes that those strongly interrelated technological infrastructures, as well as the information systems that underpin them, become highly critical, since their disruption would lead to high economical, material and, sometimes, human loss. As a consequence, the protection of these Critical Information Infrastructures is becoming a major objective for governments and companies. In this paper, we give an overview of the main challenges and open research issues on Critical Information Infrastructure security, and introduce an on-going research project that, using wireless sensor networks as an underlying technology, is dealing with those problems. Our research project focuses on the development of protection, control, evaluation, maintenance and verification mechanisms, integrated into a secure service-oriented architecture.

}, author = {Javier Lopez and Jose A. Montenegro and Rodrigo Roman} } @inproceedings {IsaacAgudo2005a, title = {Delegation Perspective of Practical Authorization Schemes}, booktitle = {Fifth International Network Conference (INC{\textquoteright}05)}, year = {2005}, pages = {157-164}, address = {Samos Island, Greece}, isbn = {960-7475-32-1}, author = {Isaac Agudo and Javier Lopez and Jose A. Montenegro and Eiji Okamoto and Ed Dawson} } @article {IsaacAgudo2005, title = {A Graphical Delegation Solution for X.509 Attribute Certificates}, journal = {ERCIM News}, number = {63}, year = {2005}, month = {October}, pages = {33-34}, publisher = {ERCIM}, issn = {0926-4981}, author = {Isaac Agudo and Javier Lopez and Jose A. Montenegro} } @inproceedings {IsaacAgudo2005b, title = {A Representation Model of Trust Relationships with Delegation Extensions}, booktitle = {3th International Conference on Trust Management (iTRUST{\textquoteright}05)}, series = {LNCS}, volume = {3477}, year = {2005}, month = {May}, pages = {9-22}, publisher = {Springer}, organization = {Springer}, address = {Versailles, France}, abstract = {

Logic languages establish a formal framework to solve authorization and delegation conflicts. However, we consider that a visual representation is necessary since graphs are more expressive and understandable than logic languages. In this paper, and after overviewing previous works using logic languages, we present a proposal for graph representation of authorization and delegation statements. Our proposal is based on Varadharajan et al. solution, though improve several elements of that work. We also discuss about the possible implementation of our proposal using attribute certificates.

}, isbn = {978-3-540-26042-4}, issn = {0302-9743 (Print) 1611-3349 (Online)}, doi = {10.1007/11429760_9}, author = {Isaac Agudo and Javier Lopez and Jose A. Montenegro} } @article {javierlopez2005c, title = {Specification and Design of Advanced Authentication and Authorization Services}, journal = {Computer Standards \& Interfaces}, volume = {27}, number = {5}, year = {2005}, month = {Jun 2005}, pages = {467-478}, publisher = {Elsevier}, abstract = {

A challenging task in security engineering concerns the specification and integration of security with other requirements at the top level of requirements engineering. Empirical studies show that it is common at the business process level that customers and end users are able to express their security needs. Among the security needs of Internet applications, authentication and authorization services are outstanding and, sometimes, privacy becomes a parallel requirement. In this paper, we introduce a methodology for the specification of security requirements and use a case study to apply our solution. We further detail the resulting system after extending it with an Authentication and Authorization Infrastructure.

}, issn = {0920-5489}, doi = {10.1016/j.csi.2005.01.005}, author = {Javier Lopez and Jose A. Montenegro and Jose L. Vivas and Eiji Okamoto and Ed Dawson} } @inproceedings {JoseA.Montenegro2004, title = {Dise{\~n}o e Implementaci{\'o}n del Marco de Trabajo de Certificado de Atributos X509 para la Delegaci{\'o}n de Privilegios}, booktitle = {VIII Reuni{\'o}n Espa{\~n}ola sobre Criptolog{\'\i}a y Seguridad de la informaci{\'o}n (VIII RECSI),Madrid}, year = {2004}, month = {Septiembre}, pages = {571-581}, abstract = {

Este trabajo muestra los detalles de una implementacion prototipo del marco de trabajo de Certificados de Atributos X.509 (Xac), propuesto por la recomendacion ITU-T. La implementacion utiliza como base de la plataforma la librer

}, author = {Jose A. Montenegro and Javier Lopez and Fernando Moya} } @inproceedings {VicenteBenjumea2004, title = {A First Approach to Provide Anonymity in Attribute Certificates}, booktitle = {2004 International Workshop on Practice and Theory in Public Key Cryptography (PKC{\textquoteright}04)}, series = {LNCS}, volume = {2947}, year = {2004}, month = {March}, pages = {402-415}, publisher = {Springer}, organization = {Springer}, abstract = {

This paper focus on two security services for internet applications:authorization and anonymity. Traditional authorization solutionsare not very helpful for many of the Internet applications; however,attribute certificates proposed by ITU-T seems to be well suited andprovide adequate solution. On the other hand, special attention is paidto the fact that many of the operations and transactions that are part ofInternet applications can be easily recorded and collected. Consequently,anonymity has become a desirable feature to be added in many cases. Inthis work we propose a solution to enhance the X.509 attribute certificatein such a way that it becomes a conditionally anonymous attributecertificate. Moreover, we present a protocol to obtain such certificatesin a way that respects users\’ anonymity by using a fair blind signaturescheme. We also show how to use such certificates and describe a fewcases where problems could arise, identifying some open problems.

}, author = {Vicente Benjumea and Javier Lopez and Jose A. Montenegro and Jose M. Troya} } @article {JavierLopez2004b, title = {PKI Design Based on the Use of On-line Certification Authorities}, journal = {International Journal of Information Security (IJIS)}, volume = {2}, number = {2}, year = {2004}, pages = {91-102}, publisher = {Springer}, abstract = {

Public-Key Infrastructures (PKIs) are considered the basis of the protocols and tools needed to guarantee the security demanded for new Internet applications like electronic commerce, government-citizen relationships and digital distribution. This paper introduces a new infrastructure design, Cert{\textquoteright}eM, a key management and certification system that is based on the structure of the electronic mail service and on the principle of near-certification. Cert{\textquoteright}eM provides secure means to identify users and distribute their public-key certificates, enhances the efficiency of revocation procedures, and avoids scalability and synchronization problems. Because we have considered the revocation problem as priority in the design process, and with a big influence in the rest of the PKI components, we have developed an alternative solution to the use of Certificate Revocation Lists (CRLs), which has become one of the strongest points in this new scheme.

}, issn = {1615-5262}, author = {Javier Lopez and Antonio Mana and Jose A. Montenegro and Juan J. Ortega} } @inproceedings {JavierLopez2004a, title = {On a Taxonomy of Systems for Authentication and/or Authorization Services}, booktitle = {TERENA Networking Conference}, year = {2004}, month = {June}, address = {Rhodes, Greece}, abstract = {

In this work we elaborate on a taxonomy of systems that provide either joint solutions for both authentication and authorization problems, or solutions for only one of the problems. Basically, we do not focus our work on theoretical systems that have been proposed only in the literature. On the other hand, we focus on: (i) systems that are already developed; (ii) systems that are under development or deployment; and (iii) systems that are still in the initial stages of design but are supported by international working groups or bodies. More precisely, we elaborate on a taxonomy of systems that are (or will be soon) available to final users.

}, author = {Javier Lopez and Jose A. Montenegro and Rolf Oppliger and Guenther Pernul} } @inproceedings {EdDawson2003, title = {BAAI: Biometric Authentication and Authorization Infrastructure}, booktitle = {IEEE International Conference on Information Technology (ITRE{\textquoteright}03)}, year = {2003}, pages = {274-278}, publisher = {IEEE}, organization = {IEEE}, abstract = {The combined use of authorization and authentication infrastructures has led to AAIs (authorization and authentication infrastructures). These new infrastructures supply identification and authorization services to a distributed environment There are many possibilities of linkages to get AAIs; one of them is to include the PMI (privilege management infrastructure) as authorization infrastructure and an authentication infrastructure that can be a PKI (public key infrastructure) or kerberos. This symbiosis gives service to applications and servers. However, in physical environments where the physical presence of an individual is required, it is necessary to use biometric systems. This paper describes the development of a solution that combines the relationship between the biometric based systems and the PMIs to finally obtain the biometric AAI.}, isbn = {0780377249}, doi = {10.1109/ITRE.2003.1270620} month={august}, author = {Ed Dawson and Javier Lopez and Jose A. Montenegro and Eiji Okamoto} } @inproceedings {JoseA.Montenegro2003, title = {Taxonom{\'\i}a de las Infraestructuras de Autorizaci{\'o}n y Autentificaci{\'o}n}, booktitle = {XIII Jornadas TELECOM I+D 2003}, year = {2003}, month = {Noviembre}, author = {Jose A. Montenegro and Javier Lopez} } @inproceedings {josevivas2003, title = {Towards Business Process-Driven Framework for Security Engineering with the UML}, booktitle = {6th International Conference on Information Security (ISC{\textquoteright}03)}, series = {LNCS}, volume = {2851}, year = {2003}, month = {October}, pages = {381-395}, publisher = {Springer-Verlag}, organization = {Springer-Verlag}, address = {Bristol, U.K.}, abstract = {

A challenging task in security engineering concerns the specification and integration of security with other requirements at the top level of requirements engineering. Empirical studies show that it is commonly at the business process level that customers and end users are able to express their security needs. In addition, systems are often developed by automating existing manual business processes. Since many security notions belongs conceptually to the world of business processes, it is natural to try to capture and express them in the context of business models in which moreover customers and end users feel most comfortable. In this paper, based on experience drawn from an ongoing work within the CASENET project \cite{CASENET}, we propose a UML-based business process-driven framework for the development of security-critical systems.

}, isbn = {1-4020-7449-2}, author = {Jose L. Vivas and Jose A. Montenegro and Javier Lopez} } @inproceedings {JavierLopez2002c, title = {Design of a VPN Software Solution Integrating TCP and UDP Services}, booktitle = {International Conference on Infrastructure Security (InfraSec{\textquoteright}02)}, series = {LNCS}, volume = {2437}, year = {2002}, month = {October}, pages = {325-337}, publisher = {Springer-Verlag}, organization = {Springer-Verlag}, address = {Bristol, U.K.}, abstract = {

The main aims of Virtual Private Network (VPN) are to isolate a distributed network from outsiders, as well as to protect the confidentiality and integrity of sensitive information traversing a non-trusted network such as the Internet. However, some problems arise when security is considered as the unique problem because VPN users suffer from restrictions in their access to the network. They are not free to use traditional Internet services such as electronic mail exchange with non-VPN users, and to access Web and FTP servers external to the organization. This paper presents a new solution that allows the open use of traditional network services running over TCP and UDP layers, while maintaining strong security features. The new scheme works at the TCP/IP transport layer and does not require the addition of new hardware because it is a totally software solution. As a consequence, the application is totally portable. Moreover, and because of its implementation at the transport layer, there is no need to modify any traditional communication applications previously installed in the network system.

}, author = {Javier Lopez and Jose A. Montenegro and Rodrigo Roman and Jorge Davila} } @inproceedings {JavierLopez2002f, title = {Designing Software Tools for the Use of Secure Electronic Forms}, booktitle = {3rd ACIS Int. Conf. on Software Engineering, Artificial Intelligence Networking and Parallel/Distributed Computing (SNPD{\textquoteright}02)}, year = {2002}, month = {Junio}, pages = {157-163}, address = {Madrid, Spain)}, abstract = {

Interaction of organizations and their clients by using the Internet can produce meaningful benefits in the accessibility, efficiency and availability of documents, regardless of time and location. However, some types of problems hinder a higher degree of communication. This paper presents some of the results of a Research Project that focuses on the influence of typical open networks risks in electronic interactions and on the need of creating software tools to manage electronic versions of the paper-based forms, as this is the traditional way of interaction through the Web.

}, author = {Javier Lopez and Antonio Mana and Jose A. Montenegro and Juan J. Ortega and Jose M. Troya} } @inproceedings {EdDawson2002, title = {A New Design of Privilege Management Infrastructure (PMIs) for Organizations Using Outsourced PKI}, booktitle = {5th International Conference on Information Security (ISC{\textquoteright}02)}, series = {LNCS}, volume = {2433}, year = {2002}, month = {September}, pages = {136-149}, publisher = {Springer-Verlag}, organization = {Springer-Verlag}, abstract = {Authentication services provided by Public Key Infrastructures (PKI) do not satisfy the needs of many e-commerce applications. These applications require additional use of authorization services in order for users to prove what they are allowed to do. Attribute certificates have changed the way in which the authorization problem has been considered until now, and Privilege Management Infrastructures (PMI) provide the necessary support for a wide use of those certificates. Although both types of infrastructures, PKIs and PMIs, keep some kind of relation, they can operate autonomously. This fact is specially interesting for companies who have taken or will take the decision to outsource PKI services. However, outsourcing PMI services is not a good option for many companies because sometimes information contained in attribute certificates is confidential. Therefore attribute certificates must be managed very carefully and, preferably, only inside the company. In this paper we present a new design of PMI that is specially suited for those companies that outsource PKI services but still need to manage the PMI internally. The scheme provides additional advantages that satisfy the needs of intra-company attribute certification, and eliminates some of the problems associated with the revocation procedures.}, isbn = {3540442707}, doi = {10.1007/3-540-45811-5_10}, author = {Ed Dawson and Javier Lopez and Jose A. Montenegro and Eiji Okamoto} } @inproceedings {JavierLopez2002i, title = {Perspectiva Composicional para el Dise{\~n}o y la Implementaci{\'o}n de una PKI}, booktitle = {I Congreso Internacional Sociedad de la Informaci{\'o}n}, year = {2002}, pages = {423-428}, address = {Las Palmas, Espa}, abstract = {
The important role of Public Key Infrastructures (PKIs) inside the general scope of Internet communication, and more precisely, inside electronic commerce, has driven us to the revision of actual procedures followed in the development of software of these elements that provide security and trust to the digital certification environment. In this work we introduce the actual results of a joint research project of the Security Group of the University of Malaga and the Department of Technology Innovation of Banesto regarding a PKI implementation. The originality of this work is that we have paid attention not only to functional aspects of the infrastructure, but also to the programming techniques used. Basically, we have developed a solution in which implementation has been guided by the increase in the study of software architectures and those paradigms that have emerged in parallel, as component orientation, software frameworks, and design patterns. The correct use of these techniques provide a different point of view that allows the development of every PKI building block in a modular and independent way.
}, author = {Javier Lopez and Jose A. Montenegro and Jose M. Troya} } @inproceedings {JavierLopez2002g, title = {Towards a Trustful and Flexible Environment for Secure Communications with Public Administrations}, booktitle = {First International Conference on Electronic Government (EGOV{\textquoteright}02)}, series = {LNCS}, volume = {2456}, year = {2002}, month = {September}, pages = {211-214}, publisher = {Springer}, organization = {Springer}, address = {Aix-en-Provence, France)}, abstract = {

Interaction of citizens and private organizations with Public Administrations can produce meaningful benefits in the accessibility, efficiency and availability of documents, regardless of time, location and quantity. Although there are some experiences in the field of e-government there are still some technological and legal difficulties that avoid a higher rate of communications with Public Administrations through Internet, not only from citizens, but also from private companies. We have studied two of the technological problems, the need to work in a trustful environment and the creation of tools to manage electronic versions of the paper-based forms.

}, author = {Javier Lopez and Antonio Mana and Jose A. Montenegro and Juan J. Ortega and Jose M. Troya} } @inproceedings {JavierAreitio2001, title = {An{\'a}lisis, Dise{\~n}o e Implementaci{\'o}n de un Entorno Escalable de Comercio-e con Seguridad Telem{\'a}tica Adaptable Basada en PKI}, booktitle = {I Simposio Espa{\~n}ol de Comercio Electr{\'o}nico (SEC{\textquoteright}01)}, year = {2001}, month = {Octubre}, pages = {145-160}, address = {M{\'a}laga, Espa}, abstract = {

La presente ponencia aborda el desarrollo de un entorno seguro escalable para el Comercio Electr\ónico. Se ha tratado la cuesti\ón en dos fases: primero, idear un prototipo generalizado distribuido seguro formado por diferentes entidades gen\éricas con el objetivo de permitir que los clientes realicen sus compras y transacciones bancarias con un nivel de seguridad escalable; y en segundo lugar, implantar en la pr\áctica un prototipo de grado de escalabilidad reducido como modelo emp\írico.

}, author = {Javier Areitio and Lorenzo Mart{\'\i}nez and Javier Lopez and Jose A. Montenegro} } @inproceedings {JavierLopez2000, title = {Aspectos de Implementaci{\'o}n de una Infraestructura de Clave P{\'u}blica Distribuida}, booktitle = {Simposio Espa{\~n}ol de Inform{\'a}tica Distribuida (SEID{\textquoteright}00)}, year = {2000}, month = {Septiembre}, pages = {313-320}, address = {Orense, Espa}, abstract = {

La seguridad es uno de los aspectos m\ás conflictivos del uso de Internet. La falta de una pol\ítica de seguridad global est\á frenando el desarrollo de Internet en \áreas tan interesantes y prometedoras como el comercio electr\ónico o la interacci\ón con las administraciones p\úblicas. Las t\écnicas criptogr\áficas actuales proporcionan un alto grado de confidencialidad; no obstante, es dif\ícil garantizar la identificaci\ón segura de los usuarios y, adem\ás, la gesti\ón de las claves de los mismos es poco eficiente y presenta graves problemas de escalabilidad. Este trabajo describe las caracter\ísticas de implementaci\ón de una soluci\ón a ambos problemas basada en una Infraestructura de Clave P\ública (PKI) que proporciona una administraci\ón simple y eficiente de las claves de los usuarios y posibilita la autenticaci\ón segura de los mismos.

}, author = {Javier Lopez and Antonio Mana and Jose A. Montenegro and Juan J. Ortega and Jose M. Troya} }