@article {sarita2018, title = {Detection of Node Capture Attack in Wireless Sensor Networks}, journal = {IEEE Systems Journal}, volume = {13}, year = {2019}, month = {03/2019}, pages = {238 - 247}, publisher = {IEEE}, issn = {1932-8184}, author = {Sarita Agrawal and Manik Lal Das and Javier Lopez} } @article {Lopez2017iotpriv, title = {Evolving privacy: From sensors to the Internet of Things}, journal = {Future Generation Computer Systems}, volume = {75}, year = {2017}, month = {10/2017}, pages = {46{\textendash}57}, publisher = {Elsevier}, abstract = {

The Internet of Things (IoT) envisions a world covered with billions of smart, interacting things capable of offering all sorts of services to near and remote entities. The benefits and comfort that the IoT will bring about are undeniable, however, these may come at the cost of an unprecedented loss of privacy. In this paper we look at the privacy problems of one of the key enablers of the IoT, namely wireless sensor networks, and analyse how these problems may evolve with the development of this complex paradigm. We also identify further challenges which are not directly associated with already existing privacy risks but will certainly have a major impact in our lives if not taken into serious consideration.\ 

}, keywords = {Challenges, Internet of Things, privacy, WSN}, issn = {0167-739X}, doi = {10.1016/j.future.2017.04.045}, author = {Javier Lopez and Ruben Rios and Feng Bao and Guilin Wang} } @inproceedings {Rios2017query, title = {Query Privacy in Sensing-as-a-Service Platforms}, booktitle = {32nd International Conference on ICT Systems Security and Privacy Protection (IFIP SEC 2017)}, series = {IFIP Advances in Information and Communication Technology (AICT)}, volume = {502}, year = {2017}, month = {05/2017}, pages = {141{\textendash}154}, publisher = {Springer}, organization = {Springer}, address = {Roma, Italy}, abstract = {

The Internet of Things (IoT) promises to revolutionize the way we interact with the physical world. Even though this paradigm is still far from being completely realized, there already exist Sensing-as-a-Service (S2aaS) platforms that allow users to query for IoT data. While this model offers tremendous benefits, it also entails increasingly challenging privacy issues. In this paper, we concentrate on the protection of user privacy when querying sensing devices through a semi-trusted S2aaS platform. In particular, we build on techniques inspired by proxy re-encryption and k-anonymity to tackle two intertwined problems, namely query privacy and query confidentiality. The feasibility of our solution is validated both analytically and empirically.\ 

}, doi = {10.1007/978-3-319-58469-0_10}, author = {Ruben Rios and David Nu{\~n}ez and Javier Lopez}, editor = {Sabrina De Capitani di Vimercati and Fabio Martinelli} } @inproceedings {Rios2016a, title = {Evoluci{\'o}n y nuevos desafios de privacidad en la Internet de las Cosas}, booktitle = {XIV Reuni{\'o}n Espa{\~n}ola sobre Criptolog{\'\i}a y Seguridad de la Informaci{\'o}n}, year = {2016}, month = {10/2016}, pages = {209-213}, address = {Mah{\'o}n, Menorca, Islas Baleares}, abstract = {

La Internet de las Cosas (en ingl{\'e}s, Internet of Things\ (IoT)) es una evoluci{\'o}n de la Internet tal y como lo conocemos. Esta nueva versi{\'o}n de Internet incorpora objetos de la vida cotidiana, rompiendo as{\'\i} barrera de los digital y extendi{\'e}ndose al mundo f{\'\i}sico. Estos objetos interactuar{\'a}n entre s{\'\i} y con otras entidades tanto de manera local como remota, y estar{\'a}n dotados de cierta capacidad computacional y sensores para que sean conscientes de lo que ocurre en su entorno. Esto traer{\'a} consigo un sinf{\'\i}n de posibilidades y nuevos servicios, pero tambi{\'e}n dar{\'a} lugar a nuevos y mayores riesgos de privacidad para los ciudadanos. En este art{\'\i}culo, estudiamos los problemas de privacidad actuales de una de las tecnolog{\'\i}as claves para el desarrollo de este prometedor paradigma, las redes de sensores, y analizamos como pueden evolucionar y surgir nuevos riesgos de privacidad al ser completamente integradas en la Internet.

}, keywords = {Challenges, Internet of Things, privacy, Sensors}, author = {Ruben Rios and Javier Lopez} } @book {Rios2016, title = {Location Privacy in Wireless Sensor Networks}, series = {CRC Series in Security, Privacy and Trust}, year = {2016}, publisher = {Taylor \& Francis}, organization = {Taylor \& Francis}, isbn = {9781498776332}, url = {https://www.crcpress.com/Location-Privacy-in-Wireless-Sensor-Networks/Rios-Lopez-Cuellar/p/book/9781498776332}, author = {Ruben Rios and Javier Lopez and Jorge Cuellar} } @article {rios2015, title = {Probabilistic receiver-location privacy protection in wireless sensor networks}, journal = {Information Sciences}, volume = {321}, year = {2015}, month = {07/2015}, pages = {205 - 223}, publisher = {Elsevier}, abstract = {

Wireless sensor networks (WSNs) are continually exposed to many types of attacks. Among these, the attacks targeted at the base station are the most devastating ones since this essential device processes and analyses all traffic generated in the network. Moreover, this feature can be exploited by a passive adversary to determine its location based on traffic analysis. This receiver-location privacy problem can be reduced by altering the traffic pattern of the network but the adversary may still be able to reach the base station if he gains access to the routing tables of a number of sensor nodes. In this paper we present HISP-NC (Homogenous Injection for Sink Privacy with Node Compromise protection), a receiver-location privacy solution that consists of two complementary schemes which protect the location of the base station in the presence of traffic analysis and node compromise attacks. The HISP-NC data transmission protocol prevents traffic analysis by probabilistically hiding the flow of real traffic with moderate amounts of fake traffic. Moreover, HISP-NC includes a perturbation mechanism that modifies the routing tables of the nodes to introduce some level of uncertainty in attackers capable of retrieving the routing information from the nodes. Our scheme is validated both analytically and experimentally through extensive simulations.

}, keywords = {node capture, privacy, security, traffic analysis, wireless sensor networks}, issn = {0020-0255}, doi = {10.1016/j.ins.2015.01.016}, author = {Ruben Rios and Jorge Cuellar and Javier Lopez} } @incollection {ruben2014a, title = {Location Privacy in WSNs: Solutions, Challenges, and Future Trends}, booktitle = {Foundations of Security Analysis and Design VII}, volume = {8604}, number = {LNCS}, year = {2014}, pages = {244-282}, publisher = {Springer}, organization = {Springer}, abstract = {

Privacy preservation is gaining popularity in Wireless Sensor Network (WSNs) due to its adoption in everyday scenarios. There are a number of research papers in this area many of which concentrate on the location privacy problem. In this paper we review and categorise these solutions based on the information available to the adversary and his capabilities. But first we analyse whether traditional anonymous communication systems conform to the original requirements of location privacy in sensor networks. Finally, we present and discuss a number of challenges and future trends that demand further attention from the research community.

}, keywords = {Location Privacy, survey, traffic analysis, wireless sensor networks}, isbn = {978-3-319-10081-4}, issn = {0302-9743}, doi = {10.1007/978-3-319-10082-1_9}, author = {Ruben Rios and Javier Lopez and Jorge Cuellar} } @inproceedings {Lopez2014prl, title = {Preserving Receiver-Location Privacy in Wireless Sensor Networks}, booktitle = {Information Security Practice and Experience (ISPEC 2014)}, volume = {8434}, year = {2014}, month = {05/2014}, pages = {15-27}, publisher = {Springer}, organization = {Springer}, address = {Fuzhou, China}, abstract = {

Wireless sensor networks (WSNs) are exposed to many different types of attacks. Among these, the most devastating attack is to compromise or destroy the base station since all communications are addressed exclusively to it. Moreover, this feature can be exploited by a passive adversary to determine the location of this critical device. This receiver-location privacy problem can be reduced by hindering traffic analysis but the adversary may still obtain location information by capturing a subset of sensor nodes in the field. This paper addresses, for the first time, these two problems together in a single solution

}, keywords = {Location Privacy, node capture, traffic analysis, wireless sensor networks}, isbn = {978-3-319-06319-5}, issn = {0302-9743}, doi = {10.1007/978-3-319-06320-1_3}, url = {http://link.springer.com/chapter/10.1007/978-3-319-06320-1_3$\#$}, author = {Javier Lopez and Ruben Rios and Jorge Cuellar} } @inproceedings {rios2013b, title = {Ocultaci{\'o}n de la estaci{\'o}n base en redes inal{\'a}mbricas de sensores}, booktitle = {XI Jornadas de Ingenier{\'\i}a Telem{\'a}tica (JITEL 2013)}, year = {2013}, month = {Oct 2013}, pages = {481-486}, publisher = {Asociaci{\'o}n de Telem{\'a}tica}, organization = {Asociaci{\'o}n de Telem{\'a}tica}, address = {Granada}, abstract = {

La estaci{\'o}n base es el elemento m{\'a}s importante en un red de sensores y, por tanto, es necesario evitar que un atacante pueda hacerse con el control de este valioso dispositivo. Para ello, el atacante puede valerse tanto de t{\'e}cnicas de an{\'a}lisis de tr{\'a}fico como de la captura de nodos. En este trabajo presentamos un esquema que consta de dos fases, la primera est{\'a} dedicada a homogeneizar los patrones de tr{\'a}fico y la segunda encargada de perturbar las tablas de rutas de los nodos. Ambas fases permiten mantener a la estaci{\'o}n base fuera del alcance del atacante con un coste computacional insignificante y un consumo energ{\'e}tico moderado. La validez de nuestro esquema ha sido validada anal{\'\i}ticamente y a trav{\'e}s de numerosas simulaciones.

}, isbn = {978-84-616-5597-7}, author = {Ruben Rios and Jorge Cuellar and Javier Lopez}, editor = {Jes{\'u}s E. D{\'\i}az Verdejo and Jorge Navarro Ortiz and Juan J. Ramos Mu{\~n}oz} } @article {Rios2012a, title = {(Un)Suitability of Anonymous Communication Systems to WSN}, journal = {IEEE Systems Journal}, volume = {7}, number = {2}, year = {2013}, month = {Jun 2013}, pages = {298 - 310}, publisher = {IEEE Systems Council}, abstract = {

Anonymous communication systems have been extensively studied by the research community to prevent the disclosure of sensitive information from the analysis of individuals{\textquoteright} traffic patterns. Many remarkable solutions have been developed in this area, most of which have proven to be effective in the protection of user privacy against different types of attacks. Recently, the privacy preservation problem has also been considered in the realm of wireless sensor networks (WSNs) due to their imminent adoption in real-world scenarios. A special challenge that arises from the analysis of the flow of sensor nodes{\textquoteright} communications is the location privacy problem. In this work we concentrate on analyzing the suitability of traditional anonymous communication systems originally designed for the Internet to the original scenario of sensor networks. The results show that, in most cases, traditional solutions do not provide the adequate protection means for the particular problem of location privacy, while other solutions are too resource-consuming for the restricted capabilities of sensor nodes.

}, keywords = {Anonymous communication, Location Privacy, wireless sensor networks}, issn = {1932-8184}, doi = {10.1109/JSYST.2012.2221956}, author = {Ruben Rios and Javier Lopez} } @article {najerascn12, title = {User-centric secure integration of personal RFID tags and sensor networks}, journal = {Security and Communication Networks}, volume = {6}, year = {2013}, month = {Oct 2013}, pages = {1177{\textendash}1197}, publisher = {Wiley-Blackwell}, abstract = {

A personal network (PN) should enable the collaboration of user{\textquoteright}s devices and services in a flexible, self-organizing and friendly manner. For such purpose, the PN must securely accommodate heterogeneous technologies with uneven computational and communication resources. In particular, personal RFID tags can enable seamless recognition of user{\textquoteright}s context, provide user authentication and enable novel services enhancing the quality and quantity of data handled by the PN. However, the highly constrained features of common RFID tags and their passive role in the network highlights the need of an adequate secure communication model with personal tags which enables their participation as a member of the PN. In this paper, we present our concept of PN, with special emphasis on the role of RFID and sensor networks, and define a secure architecture for PNs including methods for the secure access to context-aware technologies from both local PN members and the Internet of Things. The PN architecture is designed to support differentiated security mechanisms to maximize the level of security for each type of personal device. Furthermore, we analyze which security solutions available in the literature can be adapted for our architecture, as well as the challenges and security mechanisms still necessary in the secure integration of personal tags.

}, issn = {1939-0114}, doi = {10.1002/sec.684}, url = {http://dx.doi.org/10.1002/sec.684}, author = {Pablo Najera and Rodrigo Roman and Javier Lopez} } @inproceedings {Rios2012b, title = {Adecuaci{\'o}n de soluciones de anonimato al problema de la privacidad de localizaci{\'o}n en WSN}, booktitle = {XII Reuni{\'o}n Espa{\~n}ola sobre Criptolog{\'\i}a y Seguridad de la Informaci{\'o}n (RECSI 2012)}, year = {2012}, month = {Sep 2012}, pages = {309-314}, address = {Donostia-San Sebasti{\'a}n}, abstract = {

Los patrones de tr{\'a}fico caracter{\'\i}sticos de las redes inal{\'a}mbricas de sensores (WSNs) dan lugar al problema de la privacidad de localizaci{\'o}n. De manera similar, el tr{\'a}fico de los usuarios en Internet revela informaci{\'o}n sensible que puede ser protegida mediante sistemas de comunicaci{\'o}n an{\'o}nima (ACS). Por ello, este trabajo analiza la posibilidad de adaptar las soluciones de anonimato tradicionales al problema particular de las redes de sensores. Hasta el momento estas soluciones hab{\'\i}an sido rechazadas sin un an{\'a}lisis riguroso, argumentando simplemente que eran demasiado exigentes computacionalmente para los nodos sensores. Nuestros resultados demuestran que, en general, algunos ACS no cumplen los requisitos de privacidad necesarios en WSNs mientras que otros, que si los cumplen, se valen de una cantidad de recursos que superan la capacidad de los sensores.

}, isbn = {978-84-615-9933-2}, author = {Ruben Rios and Javier Lopez}, editor = {U. Zurutuza and R. Uribeetxeberria and I. Arenaza-Nu{\~n}o} } @article {Galindo2010, title = {On the Energy Cost of Authenticated Key Agreement in Wireless Sensor Networks}, journal = {Wireless Communications and Mobile Computing}, volume = {12}, year = {2012}, month = {Jan 2012}, pages = {133-143}, publisher = {Wiley}, abstract = {

Wireless sensors are battery-powered devices which are highly constrained in terms of computational capabilities, memory and communication bandwidth. While battery life is their main limitation, they require considerable energy to communicate data. Due to this, it turns out that the energy saving of computationally inexpensive primitives (like symmetric key cryptography (SKC)) can be nullified by the bigger amount of data they require to be sent. In this work, we study the energy cost of key agreement protocols between peers in a network using asymmetric key cryptography. Our main concern is to reduce the amount of data to be exchanged, which can be done by using special cryptographic paradigms like identity-based and self-certified cryptography. The main news is that an intensive computational primitive for resource-constrained devices, such as non-interactive identity-based authenticated key exchange, performs comparably or even better than traditional authenticated key exchange (AKE) in a variety of scenarios. Moreover, protocols based in this primitive can provide better security properties in real deployments than other simple protocols based on symmetric cryptography. Our findings illustrate to what extent the latest implementation advancements push the efficiency boundaries of public key cryptography (PKC) in wireless sensor networks (WSNs).

}, keywords = {identity-based key agreement, key distribution, pairings, underwater wireless sensor networks, wireless sensor networks}, issn = {1530-8669}, doi = {10.1002/wcm.894}, url = {http://dx.doi.org/10.1002/wcm.894}, author = {David Galindo and Rodrigo Roman and Javier Lopez} } @inproceedings {Rios2012d, title = {Robust Probabilistic Fake Packet Injection for Receiver-Location Privacy in WSN}, booktitle = {17th European Symposium on Research in Computer Security (ESORICS 2012)}, series = {LNCS}, volume = {7459}, year = {2012}, month = {Sep 2012}, pages = {163-180}, publisher = {Springer}, organization = {Springer}, address = {Pisa, Italy}, abstract = {

The singular communication model in wireless sensor networks (WSNs) originate pronounced traffic patterns that allow a local observer to deduce the location of the base station, which must be kept secret for both strategical and security reasons. In this work we present a new receiver-location privacy solution called HISP (Homogenous Injection for Sink Privacy). Our scheme is based on the idea of hiding the flow of real traffic by carefully injecting fake traffic to homogenize the transmissions from a node to its neighbors. This process is guided by a lightweight probabilistic approach ensuring that the adversary cannot decide with sufficient precision in which direction to move while maintaining a moderate amount of fake traffic. Our system is both validated analytically and experimentally through simulations.

}, isbn = {978-3-642-33167-1}, issn = {0302-9743}, doi = {10.1007/978-3-642-33167-1_10}, author = {Ruben Rios and Jorge Cuellar and Javier Lopez}, editor = {Sara Foresti and Moti Yung and Fabio Martinelli} } @inproceedings {Najera_STM11, title = {Secure architecure for the integration of RFID and sensors in personal networks}, booktitle = {7th International Workshop on Security and Trust Management (STM{\textquoteright}11)}, series = {LNCS}, volume = {7170}, year = {2012}, pages = {207-222}, publisher = {Springer}, organization = {Springer}, address = {Copenhagen, Denmark}, abstract = {

The secure integration of RFID technology into the personal network paradigm, as a context-aware technology which complements body sensor networks, would provide notable benefits to applications and potential services of the PN. RFID security as an independent technology is reaching an adequate maturity level thanks to research in recent years; however, its integration into the PN model, interaction with other network resources, remote users and service providers requires a specific security analysis and a PN architecture prepared to support these resource-constrained pervasive technologies. This paper provides such PN architecture and analysis. Aspects such as the management of personal tags as members of the PN, the authentication and secure communication of PN nodes and remote users with the context-aware technologies, and the enforcement of security and privacy policies are discussed in the architecture.

}, isbn = {978-3-642-29962-9}, doi = {10.1007/978-3-642-29963-6_15}, author = {Pablo Najera and Rodrigo Roman and Javier Lopez} } @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} } @inproceedings {Najera_JITEL11, title = {Acceso seguro a nodos RFID en una arquitectura de red personal}, booktitle = {X Jornadas de Ingenier{\'\i}a Telem{\'a}tica (JITEL 2011)}, year = {2011}, month = {09/2011}, pages = {104 - 111}, publisher = {Universidad de Cantabria}, organization = {Universidad de Cantabria}, address = {Santander, Spain}, abstract = {

El paradigma de red personal (PN) permitir\á la interacci\ón y colaboraci\ón del creciente abanico de dispositivos personales. Con tal fin la PN ha de integrar en su seno m\últiples tecnolog\ías heterog\éneas con diversas capacidades computacionales y de comunicaci\ón de forma segura. En particular, la incorporaci\ón de la tecnolog\ía RFID en objetos personales conlleva m\últiples riesgos de seguridad y privacidad que han suscitado un elevado inter\és de la comunidad investigadora en los \últimos a\ños. M\ás all\á de su seguridad de forma aislada, su integraci\ón en la PN y la interacci\ón de \ésta con redes de \área extensa como Internet of Things requieren una arquitectura de red personal adecuada para tal contexto. Este art\ículo proporciona los fundamentos de tal arquitectura segura incluyendo el an\álisis de aspectos como la incorporaci\ón e inicializaci\ón de las restringidas etiquetas RFID en la red personal, la autenticaci\ón tanto de miembros de la PN como de usuarios y servicios remotos en su acceso a las tecnolog\ías de contexto, el control de las pol\íticas de privacidad y el establecimiento de canales seguros de comunicaci\ón supervisados.

}, keywords = {arquitectura software, red personal, Seguridad RFID}, isbn = {978-84-694-5948-5}, author = {Pablo Najera and Rodrigo Roman and Javier Lopez}, editor = {Klaus Hackbarth and Ram{\'o}n Ag{\"u}ero and Roberto Sanz} } @article {Rios2011a, title = {Analysis of Location Privacy Solutions in Wireless Sensor Networks}, journal = {IET Communications}, volume = {5}, year = {2011}, month = {Nov 2011}, pages = {2518 - 2532}, publisher = {Institution of Engineering and Technology}, abstract = {

Extensive work has been done on the protection of Wireless Sensor Networks (WSNs) from the hardware to the application layer. However, only recently, the privacy preservation problem has drawn the attention of the research community because of its challenging nature. This problem is exacerbated in the domain of WSNs due to the extreme resource limitation of sensor nodes. In this paper we focus on the location privacy problem in WSNs, which allows an adversary to determine the location of nodes of interest to him. We provide a taxonomy of solutions based on the power of the adversary and the main techniques proposed by the various solutions. In addition, we describe and analyse the advantages and disadvantages of different approaches. Finally, we discuss some open challenges and future directions of research.

}, issn = {1751-8628}, doi = {10.1049/iet-com.2010.0825}, author = {Ruben Rios and Javier Lopez} } @article {Roman2010, title = {A Cross-layer Approach for Integrating Security Mechanisms in Sensor Networks Architectures}, journal = {Wireless Communications and Mobile Computing}, volume = {11}, year = {2011}, pages = {267-276}, publisher = {Wiley}, abstract = {

The wireless sensor networks (WSN) paradigm is especially vulnerable against external and internal attacks. Therefore, it is necessary to develop security mechanisms and protocols to protect them. These mechanisms must become an integral part of the software architecture and network stack of a sensor node. A question that remains is how to achieve this integration. In this paper we check how both academic and industrial solutions tackle this issue, and we present the concept of a transversal layer, where all the different security mechanisms could be contained. This way, all the elements of the architecture can interact with the security mechanisms, and the security mechanisms can have a holistic point of view of the whole architecture. We discuss the advantages of this approach, and also present how the transversal layer concept was applied to a real middleware architecture.

}, keywords = {architecture, cross-layer, middleware, security, Sensor Networks}, issn = {1530-8669}, doi = {10.1002/wcm.1006}, url = {http://dx.doi.org/10.1002/wcm.1006}, author = {Rodrigo Roman and Javier Lopez and Pablo Najera} } @article {Alcaraz2011, title = {An Early Warning System based on Reputation for Energy Control Systems}, journal = {IEEE Transactions on Smart Grid}, volume = {2}, number = {4}, year = {2011}, month = {Nov 2011}, pages = {827-834}, publisher = {IEEE}, abstract = {

Most of energy control or SCADA (Supervisory Control and Data Acquisition) systems are very dependent on advanced technologies and on traditional security mechanisms for protecting the a system against anomalous events. Security mechanisms are not enough to be used in critical systems, since they can only detect anomalous events occurring at a certain moment in time. For this reason it becomes of paramount importance the usage of intelligent systems with capability for preventing anomalous situations and reacting against them on time. This type of systems are, for example, Early Warning Systems (EWS). In this paper, we propose an EWS based on Wireless Sensor Networks (WSNs) (under the ISA100.11a standard) and reputation for controling the network behaviour. The WSN are organized into clusters where a Cluster Head (CH) is designated. This CH will contain a Reputation Manager Module. The usability of this approach is also analyzed considering a Smart Grid scenario.} keywords = {Critical Information Infrastructures, Sensor Networks, Early Warning Systems, Reputation, SCADA Systems, Smart Grid.

}, keywords = {Early Warning Systems, Reputation, SCADA Systems, Smart Grid, wireless sensor networks}, issn = {1949-3053}, doi = {10.1109/TSG.2011.2161498}, author = {Cristina Alcaraz and Carmen Fernandez-Gago and Javier Lopez} } @article {Rios2011b, title = {Exploiting Context-Awareness to Enhance Source-Location Privacy in Wireless Sensor Networks}, journal = {The Computer Journal}, volume = {54}, year = {2011}, month = {Sept 2011}, pages = {1603-1615}, publisher = {Oxford University Press}, abstract = {

The source-location privacy problem in Wireless Sensor Networks has been traditionally tackled by the creation of random routes for every packet transmitted from the source nodes to the base station. These schemes provide a considerable protection level at a high cost in terms of message delivery time and energy consumption. This overhead is due to the fact that the data routing process is done in a blind way, without knowledge about the location of the attacker. In this work we propose the Context-Aware Location Privacy (CALP) approach, which takes advantage of the ability of sensor nodes to perceive the presence of a mobile adversary in their vicinity in order to transmit data packets in a more energy-efficient and privacy-preserving manner. In particular, we apply the concepts of CALP to the development of a shortest-path CALP routing algorithm. A permissive and a strict version of the protocol are studied for different adversarial models and the proposed schemes are evaluated through simulation experiments in terms of privacy protection and energy consumption. Finally, we present the conclusions of the paper as well as possible extensions of this work.

}, keywords = {Context-Awareness, Location Privacy, wireless sensor networks}, issn = {0010-4620}, doi = {10.1093/comjnl/bxr055}, author = {Ruben Rios and Javier Lopez} } @article {roman2011, title = {Key management systems for sensor networks in the context of the Internet of Things}, journal = {Computers \& Electrical Engineering}, volume = {37}, year = {2011}, month = {Mar 2011}, pages = {147-159}, publisher = {Elsevier}, abstract = {

If a wireless sensor network (WSN) is to be completely integrated into the Internet as part of the Internet of Things (IoT), it is necessary to consider various security challenges, such as the creation of a secure channel between an Internet host and a sensor node. In order to create such a channel, it is necessary to provide key management mechanisms that allow two remote devices to negotiate certain security credentials (e.g. secret keys) that will be used to protect the information flow. In this paper we will analyse not only the applicability of existing mechanisms such as public key cryptography and pre-shared keys for sensor nodes in the IoT context, but also the applicability of those link-layer oriented key management systems (KMS) whose original purpose is to provide shared keys for sensor nodes belonging to the same WSN.

}, issn = {0045-7906}, doi = {10.1016/j.compeleceng.2011.01.009}, url = {http://www.sciencedirect.com/science/article/B6V25-527FRSD-1/2/62661c595153993639c43b9b331d8d66}, author = {Rodrigo Roman and Cristina Alcaraz and Javier Lopez and Nicolas Sklavos} } @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} } @inproceedings {Roman11SK, title = {SenseKey - Simplifying the Selection of Key Management Schemes for Sensor Networks}, booktitle = {5th International Symposium on Security and Multimodality in Pervasive Environments (SMPE{\textquoteright}11)}, year = {2011}, month = {March}, publisher = {IEEE}, organization = {IEEE}, address = {Singapore}, abstract = {

Key Management Schemes (KMS) are a very important security mechanism for Wireless Sensor Networks (WSN), as they are used to manage the credentials (i.e. secret keys) that are needed by the security primitives. There is a large number of available KMS protocols in the literature, but it is not clear what should network designers do to choose the most suitable protocol for the needs of their applications. In this paper, we consider that given a certain set of application requirements, the network designer can check which properties comply with those requirements and select the KMS protocols that contains those particular properties. Therefore, we study the relationship between requirements and properties, and we provide a web tool, the SenseKey tool, that can be used to automatically obtain an optimal set of KMS protocols.

}, doi = {10.1109/WAINA.2011.78}, url = {http://www.ftrai.org/smpe2011/}, author = {Rodrigo Roman and Javier Lopez and Cristina Alcaraz and Hsiao Hwa Chen} } @inproceedings {Alcaraz2010, title = {Acceso seguro a redes de sensores en SCADA a trav{\'e}s de Internet}, booktitle = {XI Reuni{\'o}n Espa{\~n}ola sobre Criptolog{\'\i}a y Seguridad de la Informaci{\'o}n (RECSI 2010)}, year = {2010}, month = {September}, pages = {337-342}, address = {Tarragona (Spain)}, abstract = {

Las Infraestructuras Cr\íticas (ICs) son monitorizadas por sistemas altamente complejos, conocidos como sistemas SCADA (Sistemas de Control y Adquisici\ón de Datos), cuyo principal soporte se encuentra en las subestaciones, las cuales miden de primera instancia el estado real de tales ICs. Para mejorar este control, la industria est\á actualmente demandando la integraci\ón en el modelo tradicional de dos avances tecnol\ógicos: Internet y las redes de sensores inal\ámbricas. Sin embargo, su incorporaci\ón requiere analizar los requisitos de seguridad que surgen en dicho contexto, as\í como diversos aspectos correlacionados (ej. mantenimiento, rendimiento, seguridad y optimizaci\ón) y, en base a estos, la estrategia de integraci\ón m\ás adecuada para satisfacer dichos requisitos. Este art\ículo proporciona dicho an\álisis en profundidad con el fin de ofrecer un modelo de integraci\ón seguro adecuado para entornos cr\íticos.

}, keywords = {el Internet, Internet of Things, Redes Mesh Inal{\'a}mbrica de Sensores, Sistemas Cr{\'\i}ticos de Control, Sistemas SCADA}, isbn = {978-84-693-3304-4}, url = {http://crises-deim.urv.cat/recsi2010/}, author = {Cristina Alcaraz and Rodrigo Roman and Pablo Najera and Javier Lopez} } @inproceedings {Alcaraz2010b, title = {Early Warning System for Cascading Effect Control in Energy Control Systems}, booktitle = {5th International conference on Critical Information Infrastructures Security (CRITIS{\textquoteright}10)}, series = {LNCS}, volume = {6712}, year = {2010}, month = {September}, pages = {55-67}, publisher = {Springer}, organization = {Springer}, address = {Athens, Greece}, abstract = {

A way of controlling a cascading effect caused by a failure or a threat in a critical system is using intelligent mechanisms capable of predicting anomalous behaviours and also capable of reacting against them in advance. These mechanisms are known as Early Warning Systems (EWS) and this will be precisely the main topic of this paper. Specially, we present an EWS design based on a Wireless Sensor Network (using the ISA100.11a standard) that constantly supervise the application context. This EWS is also based on forensic techniques to provide dynamic learning capacities. As a result, this new approach will aid to provide a reliable control of incidences by offering a dynamic alarm management, identification of the most suitable field operator to attend an alarm, reporting of causes and responsible operators, and learning from new anomalous situations.

}, keywords = {Cascading Effect, Early Warning System, Energy Control Systems, Forensic Techniques, SCADA Systems, Wireless Sensor Network}, isbn = {978-3-642-21693-0}, issn = {0302-9743}, url = {http://critis.net/2010/}, author = {Cristina Alcaraz and Angel Balastegui 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} } @inproceedings {Rios2010, title = {Source Location Privacy Considerations in Wireless Sensor Networks}, booktitle = {4th International Symposium of Ubiquitous Computing and Ambient Intelligence (UCAmI{\textquoteright}10)}, year = {2010}, month = {Sept.}, pages = {29 - 38}, publisher = {IBERGARCETA PUBLICACIONES, S.L.}, organization = {IBERGARCETA PUBLICACIONES, S.L.}, address = {Valencia (Spain)}, abstract = {

Wireless Sensor Networks are considered to be one of the cornerstones of Ambient Intelligence since they can be used in countless applications, where sensors are unobtrusively embedded into the environment to perform operations like monitoring, tracking and reporting. In such scenarios, privacy issues must be carefully considered since the mere observation of the network operation might reveal great amounts of private information to unauthorised parties. One of the problems that is gaining more attention in the realm of privacy, is the location privacy problem, which aims to prevent an attacker from obtaining the location of specific nodes of interest to him. In this paper we provide a general overview of the proposed solutions to counter this threat. Finally, we will also discuss some open challenges and future directions of research for a convenient management of privacy issues in smart environments.

}, isbn = {978-84-92812-61-5}, author = {Ruben Rios and Javier Lopez}, editor = {Lidia Fuentes and Nadia G{\'a}mez and Jos{\'e} Bravo} } @article {JavierLopezMunoz2010, title = {Trust Management Systems for Wireless Sensor Networks: Best practices}, journal = {Computer Communications}, volume = {33}, number = {9}, year = {2010}, pages = {0140-3664}, publisher = {Elsevier}, abstract = {

Wireless sensor networks (WSNs) have been proven a useful technology for perceiving information about the physical world and as a consequence has been used in many applications such as measurement of temperature, radiation, flow of liquids, etc. The nature of this kind of technology, and also their vulnerabilities to attacks make the security tools required for them to be considered in a special way. The decision making in a WSN is essential for carrying out certain tasks as it aids sensors establish collaborations. In order to assist this process, trust management systems could play a relevant role. In this paper, we list the best practices that we consider are essential for developing a good trust management system for WSN and make an analysis of the state of the art related to these practices.

}, issn = {0140-3664}, doi = {10.1016/j.comcom.2010.02.006}, author = {Javier Lopez and Rodrigo Roman and Isaac Agudo and Carmen Fernandez-Gago} } @inproceedings {calcaraz10, title = {Wireless Sensor Networks and the Internet of Things: Do We Need a Complete Integration?}, booktitle = {1st International Workshop on the Security of the Internet of Things (SecIoT{\textquoteright}10)}, year = {2010}, month = {December}, pages = {xxxx}, publisher = {IEEE}, organization = {IEEE}, address = {Tokyo (Japan)}, abstract = {

Wireless sensor networks (WSN) behave as a digital skin, providing a virtual layer where the information about the physical world can be accessed by any computational system. As a result, they are an invaluable resource for realizing the vision of the Internet of Things (IoT). However, it is necessary to consider whether the devices of a WSN should be completely integrated into the Internet or not. In this paper, we tackle this question from the perspective of security. While we will mention the different security challenges that may arise in such integration process, we will focus on the issues that take place at the network level.

}, issn = {xxxx}, author = {Cristina Alcaraz and Pablo Najera and Javier Lopez and Rodrigo Roman} } @inproceedings {Lopez2009, title = {Analysis of Security Threats, Requirements, Technologies and Standards in Wireless Sensor Networks}, booktitle = {Foundations of Security Analysis and Design 2009}, series = {LNCS}, volume = {5705}, year = {2009}, month = {August}, pages = {289-338}, publisher = {Springer Berlin/Heidelberg}, organization = {Springer Berlin/Heidelberg}, address = {Bertinoro (Italy)}, abstract = {

As sensor networks are more and more being implemented in real world settings, it is necessary to analyze how the different requirements of these real-world applications can influence the security mechanisms. This paper offers both an overview and an analysis of the relationship between the different security threats, requirements, applications, and security technologies. Besides, it also overviews some of the existing sensor network standards, analyzing their security mechanisms.

}, isbn = {978-3-642-03828-0}, issn = {0302-9743 (Print) 1611-3349 (Online)}, doi = {10.1007/978-3-642-03829-7_10}, url = {http://www.springerlink.com/content/u8h4882831k474n6/}, author = {Javier Lopez and Rodrigo Roman and Cristina Alcaraz} } @inproceedings {roman2009, title = {Do Wireless Sensor Networks Need to be Completely Integrated into the Internet?}, booktitle = {3rd CompanionAble Workshop - Future Internet of People, Things and Services (IoPTS) eco-Systems}, year = {2009}, month = {December}, pages = {xxxx}, publisher = {xxxx}, organization = {xxxx}, address = {Brussels (Belgium)}, abstract = {

Wireless sensor networks are considered as an integral part of the Internet of Things paradigm. Not only they provide a virtual presence to elements of the real world, but also allow any computationalsystem to know about the physical state of those elements thanks to the use of embedded sensors. In order to belong to the Internet of Things, the elements of a sensor network can implement Internet protocols and services such as the TCP/IP stack and web services. Still, a question that must be raised at this point of time is whether all sensor network applications should be completely integrated into the Internet or not. The purpose of this paper is to analyze this question, reviewing the challenges and security requirements of Internet-enabled sensor networks.

}, issn = {xxxx}, author = {Rodrigo Roman and Javier Lopez and Cristina Alcaraz} } @article {roman2009a, title = {Integrating Wireless Sensor Networks and the Internet: A Security Analysis}, journal = {Internet Research}, volume = {19}, number = {2}, year = {2009}, month = {Mar 2009}, pages = {246-259}, publisher = {Emerald}, abstract = {

Purpose: This paper aims to analyze the security issues that arise when integrating wireless sensor networks (WSN) and the internet. Also, it seeks to review whether existing technology mechanisms are suitable and can be applied in this context.

Design/methodology/approach: The paper considers the possible approaches that can be used to connect a WSN with the internet, and analyzes the security of their interactions.

Findings: By providing the services of the network through a front-end proxy, a sensor network and the internet can interact securely. There are other challenges to be solved if the sensor nodes are integrated into the internet infrastructure, although there exists interesting advances on his matter.

Research limitations and implications: The complete integration of sensor networks and the internet still remains as an open issue.

Practical implications: With the current state of the art, it is possible to develop a secure sensor network that can provide its services to internet hosts with certain security properties.

Originality/value: The paper studies the interactions between sensor networks and the internet from the point of view of security. It identifies both solutions and research challenges.

}, keywords = {Computer networks, Data security, Integration, Internet, Wireless}, issn = {1066-2243}, doi = {10.1108/10662240910952373}, author = {Rodrigo Roman and Javier Lopez} } @incollection {Roman2009b, title = {Trust and Reputation Systems for Wireless Sensor Networks}, booktitle = {Security and Privacy in Mobile and Wireless Networking}, year = {2009}, pages = {105-128}, publisher = {Troubador Publishing Ltd}, organization = {Troubador Publishing Ltd}, abstract = {

The concept of trust has become very relevant in the late years as a consequence of the growth of fields such as internet transactions or electronic commerce. In general, trust has become of paramount importance for any kind of distributed networks, such as wireless sensor networks (WSN in the following). In this chapter of the book, we try to give a general overview of the state of the art on trust management systems for WSN and also try to identify the main features of the architectures of these trust management systems.

}, isbn = {978-1905886-906}, author = {Rodrigo Roman and Carmen Fernandez-Gago and Javier Lopez and Hsiao Hwa Chen}, editor = {Stefanos Gritzalis and Tom Karygiannis and Charalabos Skianis} } @inproceedings {Alcaraz2008, title = {An{\'a}lisis de la Aplicabilidad de las Redes de Sensores para la Protecci{\'o}n de Infraestructuras de Informaci{\'o}n Cr{\'\i}ticas}, booktitle = {VI Jornadas de Ingenier{\'\i}a Telem{\'a}tica (JITEL{\textquoteright}08)}, year = {2008}, month = {September}, pages = {437}, address = {Alcal{\'a} de Henares (Spain)}, abstract = {

Las infraestructuras cr\íticas, como el sector energ\ético, la banca, el transporte, y muchas otras, son un pilar esencial para en bienestar de la sociedad y la econom\ía de un pa\ís. Estas infraestructuras dependen a su vez de ciertas infraestructuras de informaci\ón, las cuales permiten su correcto funcionamiento. La tarea de proteger esas infraestructuras (de informaci\ón) cr\íticas es compleja y multidimensional, con una gran cantidad de desaf\íos por resolver. Precisamente, las redes de sensores pueden ser de gran ayuda para esta tarea, debido a suscapacidades de control distribuidas y a su habilidad de funcionar en situaciones extremas. Este art\ículo analiza la utilidad de las redes de sensores en este contexto, describiendo tanto sus capacidades como sus posibles roles y mecanismos de integraci\ón para la protecci\ón de infraestructuras (de informaci\ón) cr\íticas.

}, isbn = {978-84-612-5474-3}, url = {http://www.telematica.ws/jitel/2008/default.htm}, author = {Cristina Alcaraz and Rodrigo Roman and Javier Lopez} } @inproceedings {Galindo2008a, title = {An Evaluation of the Energy Cost of Authenticated Key Agreement in Wireless Sensor Networks}, booktitle = {X Reuni{\'o}n Espa{\~n}ola sobre Criptolog{\'\i}a y Seguridad de la Informaci{\'o}n (RECSI{\textquoteright}08)}, year = {2008}, month = {September}, pages = {231-236}, address = {Salamanca (Spain)}, abstract = {

Wireless sensors are battery-powered devices which are highly constrained in terms of computational capabilities, memory, and communication bandwidth. While battery life is their main limitation, they require considerable energy to communicate data. Due to this, the energy saving of computationally inexpensive security primitives (like those using symmetric key cryptography) can be nullified by the bigger amount of data they require to be sent. In this work we study the energy cost of key agreement protocols between peers in a network using public key cryptography techniques. Our concern is to reduce the amount of data to be exchanged. Our main news is that a computationally very demanding security primitive, such as identity-based authenticated key exchange, can present energy-wise a better performance than traditional public key based key exchange in realistic scenarios such as Underwater Wireless Sensor Networks. Such a result is not to be expected in wired networks.

}, author = {David Galindo and Rodrigo Roman and Javier Lopez} } @incollection {Roman2008, title = {On the Hardware Implementation Efficiency of Cryptographic Primitives}, booktitle = {Wireless Sensor Network Security}, year = {2008}, publisher = {IOS Press}, organization = {IOS Press}, abstract = {

Security has been proven a crucial factor in the provision of data services and especially in the computer-related environments. While wired and wireless networks come to all sectors of everyday life, security tries to satisfy the growing needs for confidentiality, integrity and non-repudiation. There are many instances of security primitives and each one of them has different requirements in terms of processing power, word size, etc. Therefore, it is important to review the functionality of the less resource-demanding encryption algorithms in order to analyze their theoretical suitability to the existent sensor node hardware. Still, the constraints inherent to the sensor nodes advise against the total dependence on software-based implementations, even more in the case of expensive primitives.

}, isbn = {978-1-58603-813-7}, author = {Rodrigo Roman and Cristina Alcaraz and Nicolas Sklavos}, editor = {Javier Lopez and Jianying Zhou} } @inproceedings {Roman2008b, title = {KeyLED - Transmitting Sensitive Data over out-of-band Channels in Wireless Sensor Networks}, booktitle = {5th IEEE International Conference on Mobile Ad Hoc and Sensor Systems (MASS{\textquoteright}08)}, year = {2008}, month = {September}, pages = {796-801}, publisher = {IEEE}, organization = {IEEE}, address = {Atlanta (USA)}, abstract = {

An out-of-band (OoB) channel can be defined as an extra channel, different from the main wireless channel, that has additional security properties. They are specially suitable for protecting spontaneous interactions and exchanging sensitive data between previously unknown devices. Due to the vulnerable nature of wireless sensor networks (WSN), these kind of channels might be useful for protecting certain sensor network operations. In this paper we analyze the applicability of out-of-band channels to wireless sensor networks, and specify why an optical channel should be a good candidate for implementing an extra channel in sensor nodes. Also, we analyze how the existing security threats may affect this type of channel. Finally, the suitability and usability of optical channels for sensor networks is demonstrated by means of a prototype.

}, keywords = {Out-of-Band Channel, security, wireless sensor networks}, isbn = {978-1-4244-2574-7}, doi = {10.1109/MAHSS.2008.4660128}, author = {Rodrigo Roman and Javier Lopez} } @inproceedings {Galindo2008aa, title = {A Killer Application for Pairings: Authenticated Key Establishment in Underwater Wireless Sensor Networks}, booktitle = {Proceedings of the 7th International Conference on Cryptology and Network Security (CANS{\textquoteright}08)}, series = {LNCS}, volume = {5339}, year = {2008}, month = {December}, pages = {120-132}, publisher = {Springer}, organization = {Springer}, address = {Hong Kong (China)}, abstract = {

Wireless sensors are low power devices which are highly constrained in terms of computational capabilities, memory, and communication bandwidth. While battery life is their main limitation, they require considerable energy to communicate data. The latter is specially dramatic in underwater wireless sensor networks (UWSN), where the acoustic transmission mechanisms are less reliable and more energy-demanding. Saving in communication is thus the primary concern in underwater wireless sensors. With this constraint in mind, we argue that non-interactive identity-based key agreement built on pairings provides the best solution for key distribution in large UWSN when compared to the state of the art. At first glance this claim is surprising, since pairing computation is very demanding. Still, pairing-based non-interactive key establishment requires minimal communication and at the same time enjoys excellent properties when used for key distribution.

}, keywords = {identity-based key agreement, key distribution, pairings, underwater wireless sensor networks}, isbn = {978-3-540-89640-1}, issn = {0302-9743 (Print) 1611-3349 (Online)}, doi = {10.1007/978-3-540-89641-8_9}, url = {http://www.springerlink.com/content/g26h0115ngt12331/}, author = {David Galindo and Rodrigo Roman 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} } @inproceedings {Alcaraz2007, title = {An{\'a}lisis de primitivas criptogr{\'a}ficas para redes de sensores}, booktitle = {VI Jornadas de Ingenier{\'\i}a Telem{\'a}tica (JITEL{\textquoteright}07)}, year = {2007}, month = {September}, pages = {401-408}, address = {M{\'a}laga (Spain)}, abstract = {

Security in wireless sensor networks is very limited due to highly-constrained hardware of sensor nodes. To protect services is necessary to use secure foundations, known as security primitives, like part of a protocol. Theses primitives must assure at least confidentiality in the communication channel, authentication of the peers involved in an information exchange, and integrity of the messages. There are many primitives such as symmetric encryption, hash functions and public key cryptography, but not all of them can be supported by sensor nodes since require high resource levels, for example memory. This paper contains a deep analysis of available and suitable security primitives for sensor nodes, as well as an analysis of hardware and software implementations. Besides, it has been developed an experiment with two implementations, and it has been created a new and improved version using the optimizations of each.

}, isbn = {978-84-690-6670-6}, url = {http://www.telematica.ws/jitel/2007/}, author = {Cristina Alcaraz and Rodrigo Roman and Javier Lopez} } @inproceedings {Roman2007c, title = {Featuring Trust and Reputation Management Systems for Constrained Hardware Devices}, booktitle = {1st International Conference on Autonomic Computing and Communication Systems (Autonomics{\textquoteright}07)}, year = {2007}, month = {October}, publisher = {ICST}, organization = {ICST}, address = {Rome (Italy)}, abstract = {

Research on trust management systems for wireless sensor networks is still at a very early stage and few works have done so far. It seems that for those works which deal with the topic general features of how these systems should be are not clearly identified. In this paper we try to identify the main features that a trust management system should have and justify their importance for future developments.

}, keywords = {Sensor Networks, Trust Management}, isbn = {978-963-9799-09-7}, author = {Rodrigo Roman and Carmen Fernandez-Gago and Javier Lopez} } @incollection {Lopez2007, title = {On the Protection and Technologies of Critical Information Infrastructures.}, booktitle = {On Foundations of Security Analysis and Design IV, FOSAD 2006/2007, Springer}, series = {LNCS}, volume = {4677}, year = {2007}, note = {

10.1007/978-3-540-74810-6_6

}, pages = {160-182}, abstract = {

Critical Infrastructures are complex and highly interconnected systems that are crucial for the well-being of the society. Any type of failure can cause significant damage, affecting one or more sectors due to their inherent interdependency. Not only the infrastructures are critical, but also the information infrastructures that manage, control and supervise them. Due to the seriousness of the consequences, the protection of these critical (information) infrastructures must have the highest priority. It is the purpose of this book chapter to review and discuss about these infrastructures, to explain their elements, and to highlight their research and development issues. This chapter will also discuss the role of Wireless Sensor Network (WSN) technology in the protection of these infrastructures.

}, keywords = {Critical Information Infrastructure Protection, wireless sensor networks}, issn = {0302-9743}, doi = {10.1007/978-3-540-74810-6_6}, url = {http://dx.doi.org/10.1007/978-3-540-74810-6_6}, author = {Javier Lopez and Cristina Alcaraz and Rodrigo Roman} } @article {Roman2007a, title = {The Role of Wireless Sensor Networks in the Area of Critical Information Infrastructure}, journal = {Information Security Technical Report}, volume = {12}, number = {1}, year = {2007}, pages = {24-31}, publisher = {Elsevier}, abstract = {

Critical Infrastructures, such as energy, banking, and transport, are an essential pillar to the well-being of the national and international economy, security and quality of life. These infrastructures are dependent on a spectrum of highly interconnected information infrastructures for their smooth, reliable and continuous operation. The field of protecting such Critical Information Infrastructures, or CIIP, faces numerous challenges, such as managing the secure interaction between peers, assuring the resilience and robustness of the overall system, and deploying warning and alert systems, amongst others. In this tapestry of CIIP, Wireless Sensor Networks can be used as an invaluable tool due to their intelligent distributed control capabilities, alongside with their capability to work under severe conditions. In this paper, we justify why Wireless Sensor Networks technology is suitable for providing security for these scenarios, describing both their advantages and research issues and their role in the overall scheme of protecting the Critical Information Infrastructures.

}, keywords = {Critical Information Infrastructure Protection, Network Security, wireless sensor networks}, issn = {1363-4127}, doi = {10.1016/j.istr.2007.02.003}, url = {http://www.sciencedirect.com/science/article/B6VJC-4N6NK24-1/2/b1462973afe70af30a10b955d96ccbb6}, author = {Rodrigo Roman and Cristina Alcaraz and Javier Lopez} } @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} } @inproceedings {FernandezGago2007, title = {A Survey on the Applicability of Trust Management Systems for Wireless Sensor Networks}, booktitle = {3rd International Workshop on Security, Privacy and Trust in Pervasive and Ubiquitous Computing (SecPerU{\textquoteright}07)}, year = {2007}, pages = {25-30}, publisher = {IEEE Computer Society}, organization = {IEEE Computer Society}, address = {Istanbul (Turkey)}, abstract = {

Trust plays an important role in human life environments and virtual organizations. In the context of a network, trust may help its elements to decide whether another member of the same network is being uncooperative or malicious. Trust becomes quite important in self-configurable and autonomous systems, such as wireless sensor networks (WSN). However, very little effort has been done in the field of trust management in WSN. On the other hand, some efforts have been made in quite related fields such as Ad-hoc and P2P networks. In this paper we give an overview of existing trust management solutions, mainly those developed for Ad-Hoc and P2P networks and, more importantly, investigate their suitability to WSN. We also provide some guidelines to aid the development of trust management systems for WSN according to the nature of these networks.

}, doi = {10.1109/SECPERU.2007.3}, author = {Carmen Fernandez-Gago and Rodrigo Roman and Javier Lopez} } @inproceedings {Roman2006, title = {Applying Intrusion Detection Systems to Wireless Sensor Networks}, booktitle = {IEEE Consumer Communications \& Networking Conference (CCNC 2006)}, year = {2006}, month = {January}, pages = {640-644}, publisher = {IEEE}, organization = {IEEE}, address = {Las Vegas (USA)}, abstract = {

The research of Intrusion Detection Systems (IDS) is a mature area in wired networks, and has also attracted many attentions in wireless ad hoc networks recently. Nevertheless, there is no previous work reported in the literature about IDS architectures in wireless sensor networks. In this paper, we discuss the general guidelines for applying IDS to static sensor networks, and introduce a novel technique to optimally watch over the communications of the sensors{\textquoteright} neighborhood on certain scenarios.

}, isbn = {1-4244-0085-6}, doi = {10.1109/CCNC.2006.1593102}, author = {Rodrigo Roman and Jianying Zhou and Javier Lopez} } @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 {R.Roman2005, title = {An{\'a}lisis de Seguridad en Redes Inal{\'a}mbricas de Sensores}, booktitle = {V Jornadas de Ingener{\'\i}a Telem{\'a}tica (JITEL{\textquoteright}05)}, year = {2005}, month = {Septiembre}, pages = {335-343}, address = {Vigo (Spain)}, abstract = {

The design and development of security infrastructures and protocols for Wireless Sensor Networks is a difficult task, due to several factors like the constraints of the sensor nodes and the public nature of the communication channels. The intrinsic features of these networks create numerous security problems. In this paper, we analyze and put into perspective those problems.

}, author = {Rodrigo Roman and Javier Lopez and Jianying Zhou} } @inproceedings {Roman2005b, title = {Aplicaci{\'o}n de Sistemas de Detecci{\'o}n de Intrusiones en Redes de Sensores}, booktitle = {Simposio sobre Computaci{\'o}n Ubicua e Inteligencia Ambiental (UCAmI{\textquoteright}05)}, year = {2005}, month = {September}, pages = {113-120}, address = {Granada (Spain)}, abstract = {

Los sistemas de detecci{\'o}n de intrusiones (IDS) son una herramienta imprescindible de seguridad a la hora de proteger una red. Recientemente se han investigado y desarrollado arquitecturas de IDS para redes inal{\'a}mbricas, en concreto para redes "Ad Hoc". No obstante, no existe un trabajo previo que desarrolle una arquitectura de IDS para una red de sensores. En este art{\'\i}culo, analizamos porque los sistemas IDS de redes "Ad Hoc" no pueden aplicarse a redes de sensores, e introducimos una arquitectura de IDS para redes de sensores que incorpora una nueva t{\'e}cnica para vigilar las comunicaciones de la red en ciertos escenarios.

}, author = {Rodrigo Roman and Javier Lopez and Jianying Zhou} } @inproceedings {Roman2005e, title = {On the Security of Wireless Sensor Networks}, booktitle = {Computational Science and Its Applications (ICCSA{\textquoteright}05)}, series = {LNCS}, volume = {3482}, year = {2005}, month = {May}, pages = {681-690}, publisher = {Springer}, organization = {Springer}, address = {Singapore}, abstract = {

Wireless Sensor Networks are extremely vulnerable against any kind of internal or external attacks, due to several factors such as resource-constrained nodes and lack of tamper-resistant packages. As a result, security must be an important factor to have in mind when designing the infrastructure and protocols of sensor networks. In this paper we survey the state-of-the-art security issues in sensor networks and highlight the open areas of research.security issues in sensor networks and highlight the open areas of research.

}, isbn = {978-3-540-25862-9}, issn = {0302-9743 (Print) 1611-3349 (Online)}, doi = {10.1007/11424857_75}, url = {http://www.springerlink.com/content/pvnd4eu8b7acgtpe/}, author = {Rodrigo Roman and Jianying Zhou and Javier Lopez} }