@article {MUNOZ2023103180, title = {A survey on the (in)security of Trusted Execution Environments}, journal = {Computers \& Security}, year = {2023}, pages = {103-180}, publisher = {Elsevier}, address = {In Press}, abstract = {

As the number of security and privacy attacks continue to grow around the world, there is an ever increasing need to protect our personal devices. As a matter of fact, more and more manufactures are relying on Trusted Execution Environments (TEEs) to shield their devices. In particular, ARM TrustZone (TZ) is being widely used in numerous embedded devices, especially smartphones, and this technology is the basis for secure solutions both in industry and academia. However, as shown in this paper, TEE is not bullet-proof and it has been successfully attacked numerous times and in very different ways. To raise awareness among potential stakeholders interested in this technology, this paper provides an extensive analysis and categorization of existing vulnerabilities in TEEs and highlights the design flaws that led to them. The presented vulnerabilities, which are not only extracted from existing literature but also from publicly available exploits and databases, are accompanied by some effective countermeasures to reduce the likelihood of new attacks. The paper ends with some appealing challenges and open issues.

}, keywords = {Computer security, Hardware attacks, Secure hardware, Side-channel attacks, Software attacks, Trusted Execution Environments}, issn = {0167-4048}, doi = {https://doi.org/10.1016/j.cose.2023.103180}, url = {https://www.sciencedirect.com/science/article/pii/S0167404823000901}, author = {Mu{\~n}oz, Antonio and Ruben Rios and Rodrigo Roman and Javier Lopez} } @article {Alcaraz2021a, title = {Stakeholder Perspectives and Requirements on Cybersecurity in Europe}, journal = {Journal of Information Security and Applications}, volume = {61}, number = {102916}, year = {2021}, month = {09/2021}, publisher = {Elsevier}, keywords = {Cybersecurity, Requirements, Roadmap, Stakeholder engagement. Research \& innovation}, issn = {2214-2126}, doi = {https://doi.org/10.1016/j.jisa.2021.102916}, url = {https://www.sciencedirect.com/science/article/pii/S2214212621001381}, author = {Simone Fischer-H{\"u}bner and Cristina Alcaraz and Afonso Ferreira and Carmen Fernandez-Gago and Javier Lopez and Evangelos Markatos and Lejla Islami and Mahdi Akil} } @article {IonnaisPanosMihalisAlcarazLopez2018, title = {Survey of IoT-enabled Cyberattacks: Assessing Attack Paths to Critical Infrastructures and Services}, journal = { IEEE Communications Surveys and Tutorials}, volume = {20}, year = {2018}, month = {07/2018}, pages = {3453-3495}, publisher = {IEEE}, abstract = {

As the deployment of Internet of Things (IoT)\ is experiencing an exponential growth, it is no surprise that\ many recent cyber attacks are IoT-enabled: The attacker initially\ exploits some vulnerable IoT technology as a first step towards\ compromising a critical system that is connected, in some way,\ with the IoT. For some sectors, like industry, smart grids,\ transportation and medical services, the significance of such\ attacks is obvious, since IoT technologies are part of critical backend\ systems. However, in sectors where IoT is usually at the enduser\ side, like smart homes, such attacks can be underestimated,\ since not all possible attack paths are examined. In this paper\ we survey IoT-enabled cyber attacks, found in all application\ domains since 2010. For each sector, we emphasize on the latest,\ verified IoT-enabled attacks, based on known real-world incidents\ and published proof-of-concept attacks. We methodologically\ analyze representative attacks that demonstrate direct, indirect\ and subliminal attack paths against critical targets. Our goal is\ threefold: (i) To assess IoT-enabled cyber attacks in a risk-like\ approach, in order to demonstrate their current threat landscape;\ (ii) To identify hidden and subliminal IoT-enabled attack paths\ against critical infrastructures and services, and (iii) To examine\ mitigation strategies for all application domains.

}, keywords = {Critical Infrastructures, Cyber Attacks, Intelligent Transportation Systems, Internet of Things, SCADA, Smart grids, Smart Home, Smart Medical Systems}, issn = {1553-877X}, doi = {https://doi.org/10.1109/COMST.2018.2855563}, url = {https://ieeexplore.ieee.org/document/8410404}, author = {Ioannis Stellios and Panayiotis Kotzanikolaou and Mihalis Psarakis and Cristina Alcaraz 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} } @article {1752, title = {Security of Industrial Sensor Network-based Remote Substations in the context of the Internet of Things}, journal = {Ad Hoc Networks}, volume = {11}, year = {2013}, month = {2013}, pages = {1091{\textendash}1104}, publisher = {Elsevier}, abstract = {

The main objective of remote substations is to provide the central system with sensitive information from critical infrastructures, such as generation, distribution or transmission power systems. Wireless sensor networks have been recently applied in this particular context due to their attractive services and inherent benefits, such as simplicity, reliability and cost savings. However, as the number of control and data acquisition systems that use the Internet infrastructure to connect to substations increases, it is necessary to consider what connectivity model the sensor infrastructure should follow: either completely isolated from the Internet or integrated with it as part of the Internet of Things paradigm. This paper therefore addresses this question by providing a thorough analysis of both security requirements and infrastructural requirements corresponding to all those TCP/IP integration strategies that can be applicable to networks with constrained computational resources.

}, keywords = {Industrial Control Networks, Internet of Things, Supervisory Control and Data Acquisition (SCADA) Systems, The Internet, wireless sensor networks}, issn = {1570-8705}, doi = {http://dx.doi.org/10.1016/j.adhoc.2012.12.001}, author = {Cristina Alcaraz and Rodrigo Roman and Pablo Najera and Javier Lopez} } @article {1770, title = {Smart Control of Operational Threats in Control Substations}, journal = {Computers \& Security}, volume = {38}, year = {2013}, month = {OCT 2013}, pages = {14-27}, publisher = {Elsevier}, abstract = {

Any deliberate or unsuitable operational action in control tasks of critical infrastructures, such as energy generation, transmission and distribution systems that comprise sub-domains of a Smart Grid, could have a significant impact on the digital economy: without energy, the digital economy cannot live. In addition, the vast majority of these types of critical systems are configured in isolated locations where their control depends on the ability of a few, supposedly trustworthy, human operators. However, this assumption of reliabilty is not always true. Malicious human operators (criminal insiders) might take advantage of these situations to intentionally manipulate the critical nature of the underlying infrastructure. These criminal actions could be not attending to emergency events, inadequately responding to incidents or trying to alter the normal behaviour of the system with malicious actions. For this reason, in\ this paper we propose a smart response mechanism that controls human operators{\textquoteright} operational threats at all times. Moreover, the design of this mechanism allows the system to be able to not only evaluate by itself, the situation of a particular scenario but also to take control when areas are totally unprotected and/or isolated. The response mechanism, which is based on Industrial Wireless Sensor Networks (IWSNs) for the constant monitoring of observed critical\ infrastructures, on reputation for controlling human operators{\textquoteright} actions, and on the ISA100.11a standard for alarm management, has been implemented and simulated to evaluate its feasibility for critical contexts.

}, keywords = {Digital Economy, Energy Control Systems, Reputation, security, Smart grids, wireless sensor networks}, issn = {0167-4048}, doi = {https://doi.org/10.1016/j.cose.2013.03.013}, url = {http://www.sciencedirect.com/science/article/pii/S0167404813000588}, author = {Javier Lopez and Cristina Alcaraz and Rodrigo Roman} } @article {AlcarazR2012, title = {Selecting key management schemes for WSN applications}, journal = {Computers \& Security}, volume = {31}, number = {38}, year = {2012}, month = {Nov 2012}, pages = {956{\textendash}966}, publisher = {Elsevier}, abstract = {

Key management in wireless sensor networks (WSN) is an active research topic. Due to the fact that a large number of key management schemes (KMS) have been proposed in the literature, it is not easy for a sensor network designer to know exactly which KMS best fits in a particular WSN application. In this article, we offer a comprehensive review on how the application requirements and the properties of various key management schemes influence each other. Based on this review, we show that the KMS plays a critical role in determining the security performance of a WSN network with given application requirements. We also develop a method that allows the network designers to select the most suitable KMS for a specific WSN network setting. In addition, the article also addresses the issues on the current state-of-the-art research on the KMS for homogeneous (i.e. non-hierarchical) networks to provide solutions for establishing link-layer keys in various WSN applications and scenarios.

}, keywords = {security}, issn = {0167-4048}, doi = {10.1016/j.cose.2012.07.002}, url = {http://www.sciencedirect.com/science/article/pii/S0167404812001034}, author = {Cristina Alcaraz and Javier Lopez and Rodrigo Roman and Hsiao-Hwa Chen} } @article {Alcaraz2011a, title = {Secure SCADA Framework for the Protection of Energy Control Systems}, journal = {Concurrency and Computation Practice \& Experience}, volume = {23}, number = {12}, year = {2011}, month = {Aug 2011}, pages = {1414-1430}, publisher = {John Wiley \& Sons, Inc.}, abstract = {

Energy distribution systems are becoming increasingly widespread in today{\textquoteright}s society.\ One of the elements that is used to monitor and control these systems are the SCADA\ (Supervisory Control and Data Acquisition) systems. In particular, these control systems\ and their complexities, together with the emerging use of the Internet and wireless\ technologies, bring new challenges that must be carefully considered. Examples of such\ challenges are the particular bene{\textasciimacron}ts of the integration of those new technologies, and\ also the e{\textregistered}ects they may have on the overall SCADA security. The main task of this\ paper is to provide a framework that shows how the integration of di{\textregistered}erent state-of-the-art technologies in an energy control system, such as Wireless Sensor Networks (WSNs),\ Mobile Ad-Hoc Networks (MANETs), and the Internet, can bring some interesting\ benefits such as status management and anomaly prevention, while maintaining the\ security of the whole system.

}, keywords = {Energy Distribution and Control Systems, SCADA Systems, Sensor Networks}, isbn = {23(12)1311-1464 (2011)}, issn = {1532-0626}, doi = {10.1002/cpe.1679}, author = {Cristina Alcaraz and Javier Lopez and Jianying Zhou and Rodrigo Roman} } @article {1633, title = {Securing the Internet of Things}, journal = {IEEE Computer}, volume = {44}, number = {9}, year = {2011}, month = {Sept 2011}, pages = {51 -58}, publisher = {IEEE}, abstract = {

This paper presents security of Internet of things. In the Internet of Things vision, every physical object has a virtual component that can produce and consume services Such extreme interconnection will bring unprecedented convenience and economy, but it will also require novel approaches to ensure its safe and ethical use. The Internet and its users are already under continual attack, and a growing economy-replete with business models that undermine the Internet{\textquoteright}s ethical use-is fully focused on exploiting the current version{\textquoteright}s foundational weaknesses.

}, keywords = {business models, computer network security, Internet, Internet of Things, Internet security, IoT, virtual component}, issn = {0018-9162}, doi = {10.1109/MC.2011.291}, url = {http://dx.doi.org/10.1109/MC.2011.291}, author = {Rodrigo Roman and Pablo Najera and Javier Lopez} } @article {rosado2010d, title = {Security Services Architecture for Secure Mobile Grid Systems}, journal = {Journal of Systems Architecture}, volume = {57}, year = {2011}, month = {2011}, pages = {240-258}, publisher = {Elsevier}, address = {Mobile Grid, is a full inheritor of the Grid with the additional feature that it supports mobile users and resources. Security is an important aspect in Grid based systems, and it is more complex to ensure this in a mobile platform owing to the limitation}, abstract = {

\ Mobile Grid, is a full inheritor of the Grid with the additional feature that it supports mobile users andresources. Security is an important aspect in Grid based systems, and it is more complex to ensure thisin a mobile platform owing to the limitations of resources in these devices. A Grid infrastructure that supportsthe participation of mobile nodes and incorporates security aspects will thus play a significant rolein the development of Grid computing. The idea of developing software through systematic developmentprocesses to improve software quality is not new. However, many information systems such as those ofGrid Computing are still not developed through methodologies which have been adapted to their mostdifferentiating features. The lack of adequate development methods for this kind of systems in whichsecurity is taken into account has encouraged us to build a methodology to develop them, offering adetailed guide for their analysis, design and implementation. It is important to use software V\&V techniques,according to IEEE Std. 1012 for Software Verification and Validation, to ensure that a software systemmeets the operational needs of the user. This ensures that the requirements for the system arecorrect, complete, and consistent, and that the life-cycle products correctly design and implement systemrequirements. This paper shows part of a development process that we are elaborating for the constructionof information systems based on Grid Computing, which are highly dependent on mobile devices inwhich security plays a highly important role. In the design activity of the process, we design a securityarchitecture which serves as a reference for any mobile Grid application that we wish to build since thissecurity architecture defines a complete set of security services which will be instantiated depending onthe requirements and features found in previous activities of the process. A V\&V task is also defined in thedesign activity to validate and verify both the architecture built and the traceability of the artifacts generatedin this activity. In this paper, we will present the service-oriented security architecture for MobileGrid Systems which considers all possible security services that may be required for any mobile Grid application.

}, issn = {1383-7621}, author = {David G. Rosado and Eduardo Fernandez-Medina and Javier Lopez} } @article {rosado2011, title = {Systematic Design of Secure Mobile Grid Systems}, journal = {Journal of Network and Computer Applications}, volume = {34}, year = {2011}, month = {2011}, pages = {1168-1183}, publisher = {Elsevier}, abstract = {

\ Grid computing has arisen as an evolution of distributed systems mainly focused on the sharing of and remote access to resources in a uniform, transparent, secure, efficient and reliable manner. It is possible to join Grid technology and mobile technology in order to create one of the most promising technologies and developments to appear in recent years, in that they enrich one another and provide new solutions that solve many of the limitations and problems found in different technologies. Security is a very important factor in Mobile Grid Computing and is also difficult to achieve owing to the open nature of wireless networks and heterogeneous and distributed environments. Success in obtaining a secure system originates in incorporating security from the first stages of the development process. It has therefore been necessary to define a development process for this kind of systems in which security is incorporated in all stages of the development and the features and particularities of the Mobile Grid systems are taken into consideration. This paper presents one of the activities of this development process, the design activity, which consists of defining and designing a security software architecture. This architecture will be built from a security architecture, defined as reference architecture, in which security services, interfaces and operations are defined with the purpose of defining a reference security architecture which covers the majority of security requirements identified in the analysis activity. The design activity will build the system architecture that will be the input artefact for the subsequent activity in the process, which is the construction activity.

}, issn = {1084-8045}, author = {David G. Rosado and Eduardo Fernandez-Medina and Javier Lopez and Mario Piattini} } @article {Agudo2010b, title = {A Scale Based Trust Model for Multi-Context Environments}, journal = {Computers and Mathematics with Applications}, volume = {60}, year = {2010}, month = {July}, pages = {209-216}, publisher = {Elsevier}, abstract = {

When interactions among users of a system have to take place, for example, over the internet, establishing trust relationships among these users becomes crucial. However, the way this trust is established depends to a certain extent on the context where the interactions take place. Most of the time, trust is encoded as a numerical value that might not be very meaningful for a not very experienced user. In this paper we propose a model that takes into account the semantic and the computational sides of trust. This avoids users having to deal directly with the computational side; they instead deal with meaningful labels such as Bad or Good in a given context.

}, issn = {0898-1221}, doi = {10.1016/j.camwa.2010.02.009}, author = {Isaac Agudo and Carmen Fernandez-Gago and Javier Lopez} } @article {Alcaraz2010a, title = {A Security Analysis for Wireless Sensor Mesh Networks in Highly Critical Systems}, journal = {IEEE Transactions on Systems, Man, and Cybernetics, Part C: Applications and Reviews}, volume = {40}, number = {4}, year = {2010}, month = {July}, pages = {419-428}, publisher = {IEEE}, abstract = {

Nowadays, critical control systems are a fundamental component contributing to the overall performance of critical infrastructures in our society, most of which belong to the industrial sector. These complex systems include in their design different types of information and communication technology systems, such as wireless (mesh) sensor networks, to carry out control processes in real time. This fact has meant that several communication standards, such as Zigbee PRO, WirelessHART, and ISA100.11a, have been specified to ensure coexistence, reliability, and security in their communications. The main purpose of this paper has been to review these three standards and analyze their security. We have identified a set of threats and potential attacks in their routing protocols, and we consequently provide recommendations and countermeasures to help Industry protect its infrastructures.

}, keywords = {Critical Control Systems, Critical Infrastructure Protection, SCADA Systems, Wireless Sensor Mesh Network}, issn = {1094-6977}, doi = {10.1109/TSMCC.2010.2045373}, url = {http://ieeexplore.ieee.org/search/srchabstract.jsp?tp=\&arnumber=5443456\&queryText\%253DC.+Alcaraz\%2526openedRefinements\%253D*\%2526searchField\%253DSearch+All\&fromGateway=true}, author = {Cristina Alcaraz and Javier Lopez} } @article {vivas2009, title = {A security framework for a workflow-based grid development platform.}, journal = {Computer Standards and Interfaces}, volume = {32}, number = {5-6}, year = {2010}, month = {Oct 2010}, pages = {230-245}, publisher = {Elsevier}, abstract = {

This paper describes the security framework that is to be developed for the generic grid platform created for the project GREDIA. This platform is composed of several components that need to be secured. The platform uses the OGSA standards, so that the security framework will follow GSI, the portion of Globus that implements security. Thus, we will show the security features that GSI already provides and we will outline which others need to be created or enhanced.

}, issn = {0920-5489}, doi = {http://dx.doi.org/10.1016/j.csi.2009.04.001}, author = {Jose L. Vivas and Carmen Fernandez-Gago and Andres Benjumea and Javier Lopez} } @article {1705, title = {Secure multiparty payment with an intermediary entity}, journal = {Computers and Security}, volume = {28}, number = {5}, year = {2009}, pages = {289-300}, publisher = {Elsevier}, issn = {0167-4048}, author = {Mildrey Carbonell and Jose Maria Sierra and Javier Lopez} } @article {Najera2009, title = {Security Mechanisms and Access Control Infrastructure for e-Passports and General Purpose e-Documents}, journal = {Journal of Universal Computer Science}, volume = {15}, year = {2009}, pages = {970-991}, abstract = {

Traditional paper documents are not likely to disappear in the near future as they are present everywhere in daily life, however, paper-based documentation lacks the link with the digital world for agile and automated processing. At the same time it is prone to cloning, alteration and counterfeiting attacks. E-passport defined by ICAO and implemented in 45 countries is the most relevant case of hybrid documentation (i.e. paper format with electronic capabilities) to date, but, as the advantages of hybrid documentation are recognized more and more will undoubtedly appear. In this paper, we present the concept and security requirements of general-use e-documents, analyze the most comprehensive security solution (i.e. ePassport security mechanisms) and its suitability for general-purpose e-documentation. Finally, we propose alternatives for the weakest and less suitable protocol from ePassports: the BAC (Basic Access Control). In particular, an appropriate key management infrastructure for access control to document memory is discussed in conjunction with a prototype implementation.

}, issn = {0948-695X}, doi = {http://dx.doi.org/10.3217/jucs-015-05-0970}, url = {http://www.jucs.org/jucs_15_5/security_mechanisms_and_access}, author = {Pablo Najera and Francisco Moyano and Javier Lopez} } @article {Alcaraz2008b, title = {Secure Management of SCADA Networks}, journal = {Novatica, New Trends in Network Management}, volume = {9}, number = {6}, year = {2008}, month = {December}, pages = {22-28}, publisher = {Cepis UPGRADE}, abstract = {

When a Supervisory Control and Data Acquisition (SCADA) system monitors and manages other complex infrastructures through the use of distributed technologies, it becomes a critical infrastructure by itself: A failure or disruption in any of its components could implicate a serious impact on the performance of the other infrastructures. The connection with other systems makes a SCADA system more vulnerable against attacks, generating new security problems. As a result, it is essential to perform diverse security analysis frequently in order to keep an updated knowledge and to provide recommendations and/or solutions to mitigate or avoid anomalous events. This will facilitate the existence of a suitable, reliable, and available control network.

}, keywords = {SCADA network management, Security Analysis, Supervisory Control and Data Acquisition Systems}, issn = {1684-5285}, url = {http://www.upgrade-cepis.org/issues/2008/6/up9-6Alcaraz.pdf}, author = {Cristina Alcaraz and Gerardo Fernandez and Rodrigo Roman and Angel Balastegui and Javier Lopez} } @article {Roman2008a, title = {Situation Awareness Mechanisms for Wireless Sensor Networks}, journal = {IEEE Communications Magazine}, volume = {46}, number = {4}, year = {2008}, month = {April}, pages = {102-107}, publisher = {IEEE}, abstract = {

A wireless sensor network should be able to operate for long periods of time with little or no external management. There is a requirement for this autonomy: the sensor nodes must be able to configure themselves in the presence of adverse situations. Therefore, the nodes should make use of situation awareness mechanisms to determine the existence of abnormal events in their surroundings. This work approaches the problem by considering the possible abnormal events as diseases, thus making it possible to diagnose them through their symptoms, namely, their side effects. Considering these awareness mechanisms as a foundation for high-level monitoring services, this article also shows how these mechanisms are included in the blueprint of an intrusion detection system.

}, issn = {0163-6804}, doi = {10.1109/MCOM.2008.4481348}, author = {Rodrigo Roman and Javier Lopez and Stefanos Gritzalis} } @article {Roman2007, title = {A Survey of Cryptographic Primitives and Implementations for Hardware-Constrained Sensor Network Nodes}, journal = {Mobile Networks and Applications}, volume = {12}, number = {4}, year = {2007}, month = {August}, pages = {231-244}, publisher = {Springer}, abstract = {

In a wireless sensor network environment, a sensor node is extremely constrained in terms of hardware due to factors such as maximizing lifetime and minimizing physical size and overall cost. Nevertheless, these nodes must be able to run cryptographic operations based on primitives such as hash functions, symmetric encryption and public key cryptography in order to allow the creation of secure services. Our objective in this paper is to survey how the existing research-based and commercial-based sensor nodes are suitable for this purpose, analyzing how the hardware can influence the provision of the primitives and how software implementations tackles the task of implementing instances of those primitives. As a result, it will be possible to evaluate the influence of provision of security in the protocols and applications/scenarios where sensors can be used.

}, keywords = {Cryptography, Hardware, Sensor Networks}, issn = {1383-469X}, doi = {10.1007/s11036-007-0024-2}, url = {http://www.springerlink.com/content/3785k818327456gq/}, author = {Rodrigo Roman and Cristina Alcaraz and Javier Lopez} } @article {VicenteBenjumea2006, title = {Specification of a Framework for the Anonymous Use of Privileges}, journal = {Telematics and Informatics}, volume = {23}, number = {3}, year = {2006}, pages = {179-195}, publisher = {Elsevier}, abstract = {

In this paper we have defined an open framework to support open distributed applications where anonymous transactions based on user privileges play an important role. The goal of the framework is to provide a basis to the application level, and is presented from an open and general perspective where many different implementation schemes can fit. Moreover, we have presented a set of requirements that implementation schemes must fulfill to conform a fully anonymous privilege system, which guarantees to supported applications that anonymity will be preserved in remote transactions. Finally, we present an application scenario using the services provided by the framework in order to better show the possibilities of what this type of systems offers.

}, issn = {0736-5853}, author = {Vicente Benjumea and Javier Lopez and Jose M. Troya} } @article {JavierLopez2005b, title = {Security Protocols Analysis: A SDL-based Approach}, journal = {Computer Standards \& Interfaces}, volume = {27}, number = {3}, year = {2005}, pages = {489-499}, publisher = {Elsevier}, abstract = {

Organizations need to develop formally analyzed systems in order to achieve well-known formal method benefits. In order to study the security of communication systems, we have developed a methodology for the application of the formal analysis techniques, commonly used in communication protocols, to the analysis of cryptographic protocols. In particular, we have extended the design and analysis phases with security properties. Our proposal uses a specification notation based on one of the most used standard requirement languages HMSC/MSC, which can be automatically translated into a generic SDL specification. The SDL system obtained can then be used for the analysis of the addressed security properties, by using an observer process schema. Besides our main goal to provide a notation for describing the formal specification of security systems, our proposal also brings additional benefits, such as the study of the possible attacks to the system, and the possibility of re-using the specifications produced to describe and analyse more complex systems.

}, issn = {0920-5489}, author = {Javier Lopez and Juan J. Ortega and Jose M. Troya} } @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} } @article {1708, title = {A Secure Solution for Commercial Digital Libraries}, journal = {Online Information Review Journal}, volume = {27}, number = {3}, year = {2003}, pages = {147-159}, publisher = {Emerald}, issn = {1468-4527}, author = {Javier Lopez and Antonio Mana and Ernesto Pimentel and Jose maria troya and Marienma Yague} } @article {1713, title = {Servicios de Notarizaci{\'o}n Electr{\'o}nica}, journal = {Revista SIC: Seguridad en Inform{\'a}tica y Comunicaciones}, volume = {38}, year = {2001}, pages = {1-5}, issn = {1136-0623}, author = {Javier Lopez} } @article {1712, title = {Sistemas Electr{\'o}nicos de Micropago}, journal = {Revista de Contrataci{\'o}n Electr{\'o}nica}, volume = {22}, year = {2001}, pages = {3-22}, issn = {1576-2033}, author = {Jorge Davila and Javier Lopez} }