BUSCADOR RECOLECTA

The evolution of traditional electricity distribution infrastructures towards Smart Grid networks has generated the need to carry out new research. There are many fields that have attracted the attention of researchers, among which is the improvement of the performance of the so-called Neighborhood Area Networks (NAN). In this paper, three mechanisms for these kind of networks are proposed, implemented and evaluated: traffic differentiation, multichannel allocation and congestion control. These proposals have been evaluated in the context of a wireless mesh networks (WMN) made up by a set of smart meter devices, where various smart grids (SG) applications are sending their data traffics. Each SG
application must meet its unique quality of service (QoS) requirements, such as reliability and delay. To evaluate the proposals, we have built some NAN scenarios by using the ns-3 simulator and its 802.11s basic model, which we have modified to implement our techniques. Compared with the basic Hybrid Wireless Mesh Protocol (HWMP), our modifications, multiple channel (M-HWMP) and congestion control (MC-HWMP), show improvements in terms of packet delivery ratio and transit time., Peer Reviewed

© 2018 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes,creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works., For a long time, the Internet and web technologies have supported a more fluid interaction between public institutions and citizens through e-government. With this spirit, several public services are being offered online. One of such services, though not a standard one, is transparency. Strongly encouraged by open-data initiatives, transparency is being marketed as a powerful mechanism to fight corruption. Leveraging communication technologies, societies are broadly adopting online transparency practices to give the general public more control over the scrutiny of state institutions. However, a neglected implementation of transparency may cause almost unlimited access to large amounts of information, a side effect we call hyper-transparency. Inevitably, serious privacy risks arise for the individuals in this context. In this work, we analyze the emergence of hyper-transparent practices in Ecuador, a country recently involved in a fierce attempt to offer free access to public information as a fundamental right enabled through e-government. Moreover, we systematically dissect the large amount of microdata released online by Ecuadorian public institutions. Accordingly, we also unveil here a scenario where sensitive information of public employees is openly released under transparency laws. After exposing potential privacy violations, we elaborate on some mechanisms aimed at protecting citizens from such violations, Peer Reviewed

© <2019>. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/, The evolution of traditional electricity distribution infrastructures towards Smart Grid networks has generated the need to carry out new research. There are many fields that have attracted the attention of researchers, among which is the improvement of the performance of the so-called Neighborhood Area Networks (NAN). In this sense, and given the critical nature of some of the data transmitted by these networks, maintaining an adequate quality of service (QoS) is absolutely necessary. In emergency situations, this need becomes even more evident. This article presents a congestion control mechanism, whose parameters are modified according to the network state of emergency. The mechanism also applies a multi-channel allocation technique, together with a differentiation in the QoS offered to the different data flows according to their relevance. These proposals have been evaluated in the context of a wireless mesh networks (WMN) made up by a set of smart meter devices, where various smart grids (SG) applications are sending their data traffics. Each SG application must meet its unique quality of service (QoS) requirements, such as reliability and delay. To evaluate the proposals, some NAN scenarios have been built by using the ns-3 simulator and its 802.11s basic model, which was modified to implement the proposed techniques. Compared with the basic Hybrid Wireless Mesh Protocol (HWMP), Emergency Aware Congestion Control proposal (EA-HWMP), shows significant improvements in terms of packet delivery ratio, network throughput and transit time., Peer Reviewed

Cybersecurity logs are permanently generated by network devices to describe security incidents. With modern computing technology, such logs can be exploited to counter threats in real time or before they gain a foothold. To improve these capabilities, logs are usually shared with external entities. However, since cybersecurity logs might contain sensitive data, serious privacy concerns arise, even more when critical infrastructures (CI), handling strategic data, are involved.

We propose a tool to protect privacy by anonymizing sensitive data included in cybersecurity logs. We implement anonymization mechanisms grouped through the definition of a privacy policy. We adapt said approach to the context of the EU project CIPSEC that builds a unified security framework to orchestrate security products, thus offering better protection to a group of CIs. Since this framework collects and processes security-related data from multiple devices of CIs, our work is devoted to protecting privacy by integrating our anonymization approach., Peer Reviewed

MobilitApp is a platform designed to provide smart mobility services in urban areas. It is designed to help citizens and transport authorities alike. Citizens will be able to access the MobilitApp mobile application and decide their optimal transportation strategy by visualising their usual routes, their carbon footprint, receiving tips, analytics and general mobility information, such as traffic and incident alerts. Transport authorities and service providers will be able to access information about the mobility pattern of citizens to offer their best services, improve costs and planning. The MobilitApp client runs on Android devices and records synchronously, while running in the background, periodic location updates from its users. The information obtained is processed and analysed to understand the mobility patterns of our users in the city of Barcelona, Spain., Peer Reviewed

This is a post-peer-review, pre-copyedit version of an article published in Eurasip journal on wireless communication and networking. The final authenticated version is available online at: http://dx.doi.org/10.1186/s13638-019-1375-7, Routing in mobile ad hoc networks is based on the cooperation of the network’s nodes. The presence of selfish nodes that do not cooperate in this task drastically reduces the number of delivered packets. In order to find the better paths that include nodes willing to cooperate, we propose a new routing algorithm based on the reputation of the nodes. In our proposal, each node locally assigns a reputation value to the rest of the nodes in the network and next it uses the assigned reputation values to find out the better routing paths, in order to minimize the overall packet loss ratio. We assume that nodes have a stationary routing behavior, but we also include a mechanism to detect changes in their behavior. Our approach has been evaluated in the presence of selfish nodes, in order to compare it with the dynamic source routing algorithm, obtaining a reduction in the packet loss ratio at the expenses of a small increase in the number of hops taken by the packets to reach their destinations., This work was supported in part by the Spanish Government under projects
INRISCO (TEC2014–-54335-C4-1-R) and MAGOS (TEC2017-84197-C4-3-R)., Peer Reviewed

This paper proposes different local\hyph search heuristics to improve the performance of geographical routing protocols in VANET networks, which typically relies the selection of the next node only on the best candidate. The presented algorithms are based on modifications of well-known metaheuristics such as simulated annealing, metropolis and tabu. We divided our heuristics according to their operation in forwarding and recovery algorithms. However, a simultaneous use of some of them is also possible to improve the overall performance of the system. Simulation results of the proposed implementation of tabu-search in our routing proposal show a promising increment in the packet delivery ratio., Peer Reviewed

In vehicular networks, the packet losses in the path between source and destination occur due to packet collisions, fast movement and a limited communication range of vehicles. Reliability mechanisms at different layers are used to mitigate the impact of this issue. In this work, we explain how the loss of ACK frames at MAC layer in conjunction with the recovery procedure of VANET routing protocols lead to an unexpected generation of duplicate packets. Also, we propose a duplicate packet filtering at routing layer to prevent the propagation of unnecessary packet copies and therefore increasing the available bandwidth. To evaluate the behavior of our proposal to minimize the duplicate packets in against not to use any filter, we use MMMR routing protocol, a geographical routing protocol for VANETs and carried out simulations with different vehicle densities in a urban scenario. Our results show that our approach is effective reducing the load of the network in terms of routing operations, idle time, the total number of frames transmitted and end-to-end delay. These improvements are related to a minimum degradation of the packet delivery ratio., Peer Reviewed

We have created a representative dataset based on the collection of different traffic metrics from VANET simulations in urban scenarios. The five collected metrics that compose the dataset used to train and test our ML-based forwarding algorithm are available bandwidth, distance to destination, vehicles’ density, MAC layer losses, and vehicle’s trajectory. Notice that those metrics are gathered by the vehicles from the beacons periodically interchanged with the vehicles in their neighborhood (i.e., with vehicles within their transmission range). This way, nodes have local knowledge of the VANET, according to the decentralized nature inherent in VANETs.

In order to improve the management mechanisms of the electric energy transport infrastructures, the smart grid networks have associated data networks that are responsible for transporting the necessary information between the different elements of the electricity network and the control center. Besides, they make possible a more efficient use of this type of energy. Part of these data networks is comprised of the Neighborhood Area Networks (NANs), which are responsible for interconnecting the different smart meters and other possible devices present at the consumers' premises with the control center. Among the proposed network technologies for NANs, wireless technologies are becoming more relevant due to their flexibility and increasing available bandwidth. In this paper, some general modifications are proposed for the routing protocol of the wireless multi-hop mesh networks standardized by the IEEE. In particular, the possibility of using multiple paths and transmission channels at the same time, depending on the quality of service needs of the different network traffic, is added. The proposed modifications have been implemented in the ns-3 simulator and evaluated in situations of high traffic load. Simulation results show improvements in the network performance in terms of packet delivery ratio, throughput and network transit time., Peer Reviewed

The need for significant improvements in the management and efficient use of electrical energy has led to the evolution from the traditional electrical infrastructures towards modern Smart Grid networks. Taking into account the critical importance of this type of networks, multiple research groups focus their work on issues related to the generation, transport and consumption of electrical energy. One of the key research points is the data communication network associated with the electricity transport infrastructure, and specifically the network that interconnects the devices in consumers' homes, the so-called Neighborhood Area Networks (NANs). In this paper, a new distributed congestion control mechanism is proposed, implemented and evaluated for NANs. Besides, different priorities have been considered for the traffic flows transmitted by different applications. The main goal is to provide with the needed Quality of Service (QoS) to all traffic flows, especially in high traffic load situations. The proposal is evaluated in the context of a wireless ad hoc network made up by a set of smart meter devices, using the Ad hoc On-Demand Distance Vector (AODV) routing protocol and the IEEE 802.11ac physical layer standard. The application of the proposed congestion control mechanism, together with the necessary modifications made to the AODV protocol, lead to performance improvements in terms of packet delivery ratio, network throughput and transit time, fairness between different traffic sources and QoS provision., This work was supported by the Spanish Research Council underprojects INRISCO (TEC2014-54335-C4-1-R) and MAGOS (TEC2017-84197-C4-3-R), and Juan Pablo Astudillo León is the recipient of afull scholarship from the Secretaria Nacional de Educación Superior,Ciencia y Tecnología, Peer Reviewed

The dissemination of video information contents migth enhance the performances of safety-related applications in vehicular ah-hoc networks (VANETs). A major problem concerns the high sensitivity of the compressed video streams to the severe channel conditions in wireless ad-hoc networks. The reliable dissemination of video contents in mobile environments is recognized as one of the main challenges for the developing and deploying of VANETs. To improve the robustness of dissemination, we propose RCP+ (Road-Casting Protocol) scheme for distributing high-definition video contents in VANETs. RCP+ is a cross layer dissemination mechanism for video safety messages that specifically addresses highway scenarios with zero infrastructure support. Also, a comparison of one of the most popular and widely spread video encoder H.264/AVC with respect to the recently released video coding scheme H.265/HEVC is presented. The comparison is performed by means of simulations showing differences between encoding algorithms in terms of perceived quality. The results indicate a better performance of HEVC based encoding algorithm in comparison to AVC in VANET environments., Peer Reviewed

Video content delivery for vehicular ad hoc networks (VANETs) is envisioned to be of high benefit for road safety, traffic management as well as for providing value-added vehicle services. In this paper, we evaluate five existing dissemination mechanisms in a realistic urban scenario. We also propose RCP+ as a renovated mechanism for adaptative video streaming over VANETs. RCP+ is a cross layer dissemination mechanism for video safety messages that specifically addresses urban scenarios with zero infrastructure support. Through simulations, we compare our proposal with other distributed dissemination mechanisms. The performance evaluation shows that our proposal mechanism is more suitable for video transmission in realistic urban scenarios. The results also indicate that a modified frame coding approach provides many opportunities for multimedia services., Peer Reviewed

© <2019>. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/, The expected increase in the number of electric vehicles (EVs) in the coming years will contribute to reducing CO2 pollution in our cities. Currently, EVs' users may suffer from distress due to long charging service times and overloaded charging stations (CSs). Critical traffic conditions (e.g., traffic jams) affect EVs' trip time (TT) towards CSs and thus influence the total trip duration. With this concern, Intelligent transport systems (ITS) and more specifically connected vehicle technologies, can leverage an efficient real-time EV charging service by jointly considering CSs status and traffic conditions in the city. In this work, we propose a scheme to manage EVs' charging planning, focusing on the selection of a CS for the energy-requiring EV. The proposed scheme considers anticipated charging slots reservations performed through a vehicular ad hoc network (VANET), which has been regarded as a cost-efficient communication framework. In specific, we consider two aspects: 1) the EV's total trip time towards its destination considering an intermediate charging at each candidate CS, and 2) the communication delay of the VANET routing protocol. First, in order to estimate the EV's total trip time, our CS selection scheme takes into account the average road speed, traffic lights, and route distance, along the path of the EV. The optimal CS that produces the minimum total charging service time (including the TT) is suggested to that energy-requiring EV. Then, we introduce two communication modes based on geographical routing protocols for VANETs to attain an anticipated charging slot reservation. Simulation results show that with our charging scheme EVs' charging service time is reduced and more EVs are successfully charged., Peer Reviewed

Improvements in technology have led to enormous volumes of detailed personal information made available for any number of statistical studies. This has stimulated the need for anonymization techniques striving to attain a difficult compromise between the usefulness of the data and the protection of our privacy. k-Anonymous microaggregation permits releasing a dataset where each person remains indistinguishable from other k–1 individuals, through the aggregation of demographic attributes, otherwise a potential culprit for respondent reidentification. Although privacy guarantees are by no means absolute, the elegant simplicity of the k-anonymity criterion and the excellent preservation of information utility of microaggregation algorithms has turned them into widely popular approaches whenever data utility is critical. Unfortunately, high-utility algorithms on large datasets inherently require extensive computation. This work addresses the need of running k-anonymous microaggregation efficiently with mild distortion loss, exploiting the fact that the data may arrive over an extended period of time. Specifically, we propose to split the original dataset into two portions that will be processed subsequently, allowing the first process to start before the entire dataset is received, while leveraging the superlinearity of the microaggregation algorithms involved. A detailed mathematical formulation enables us to calculate the optimal time for the fastest anonymization, as well as for minimum distortion under a given deadline. Two incremental microaggregation algorithms are devised, for which extensive experimentation is reported. The theoretical methodology presented should prove invaluable in numerous data-collection applications, including largescale electronic surveys in which computation is possible as the data comes in., Peer Reviewed

The design of routing protocols in vehicular ad hoc networks (VANETs) is fundamental to achieve a high packets’ delivery ratio. Routing protocols whose operation considers the nodes’ positions use updated routing information according to the reception frequency of hello messages. The routing information can help to improve the routing operation by including several metrics such as vehicle’s trajectory, vehicle’s density, percentage of packet losses, among others. In addition, there is a trade-off between the beaconing frequency and the overhead injected to the network: a high frequency provides a better accuracy on selecting the best forwarding node to route a packet but at the same time the overhead is increased. However, a low frequency will provide less accuracy on selecting the best forwarding candidate node but the overhead injected to the network will be decreased. In this paper we have designed an efficient method to improve the accuracy of the nodes’ position used to select the next forwarding node without any modification on the beaconing frequency value. Our approach improves the operation of the routing protocol used in our performance evaluation. Simulations show the benefits of our proposal, increasing the accuracy of the nodes’ selection and maintaining the same level of overhead, without the necessity to increase the beacon frequency., Thiswork was supported by the Spanish Government under Projects Secure “sMARt Grid using Open Source Intelligence. Data Privacy and reliable communications” (MAGOS), TEC2017-84197-C4-3-R and “INcident monitoRing In Smart COmmunities” (INRISCO),TEC2014- 54335-C4-1-R. Leticia Lemus and Nely López are recipients of a Ph.D. grant from the Academic Coordination of the University of Guadalajara, México. Pablo Barbecho is recipient of a grant from the Secretaría Nacional de Educación Superior, Ciencia y Tecnología SENESCYT, Ecuador., Peer Reviewed

Websites and applications use personalisation services to profile their users, collect their patterns and activities and eventually use this data to provide tailored suggestions. User preferences and social interactions are therefore aggregated and analysed. Every time a user publishes a new post or creates a link with another entity, either another user, or some online resource, new information is added to the user profile. Exposing private data does not only reveal information about single users’ preferences, increasing their privacy risk, but can expose more about their network that single actors intended. This mechanism is self-evident in social networks where users receive suggestions based on their friends’ activities. We propose an information-theoretic approach to measure the differential update of the anonymity risk of time-varying user profiles. This expresses how privacy is affected when new content is posted and how much third-party services get to know about the users when a new activity is shared. We use actual Facebook data to show how our model can be applied to a real-world scenario., Peer Reviewed

© <2020>. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/, Identification and authentication (IA) are security procedures that are ubiquitous in
our online life, and that constantly require disclosing personal, sensitive information to non-fully
trusted service providers, or to fully trusted providers that unintentionally may fail to protect such information. Although user IA processes are extensively supported by heterogeneous software and hardware, the simultaneous protection of user privacy is an open problem.
From a legal point of view, the European Union legislation requires protecting the processing
of personal data and evaluating its impact on privacy throughout the whole IA procedure. Privacy Threat Analysis (PTA) is one of the pillars for the required Privacy Impact Assessment (PIA). Among the few existing approaches for conducting a PTA, LINDDUN is a very promising framework, although generic, in the sense that it has not been specifically conceived for IA.
In this work, we investigate an extension of LINDDUN that allows performing a reliable and
systematically-reproducible PTA of user IA processes, thereby contributing to one of the cornerstones of PIA. Specifically, we propose a high-level description of the IA verification process, which we illustrate with an UML use case. Then, we design an identification and authentication modelling framework, propose an extension of two critical steps of the LINDDUN scheme, and adapt and tailor the trust boundary concept applied in the original framework. Finally, we propose a systematic methodology aimed to help auditors apply the proposed improvements to the LINDDUN framework., The authors are thankful for the support through the research project “INRISCO”, ref. TEC2014-54335-C4-1-R, “MAGOS”, TEC2017-84197-C4-3-R, and the project “Sec-MCloud”, ref. TIN2016-80250-R. J. Parra-Arnau is the recipient of a Juan de la Cierva postdoctoral fellowship, IJCI-2016–28239, from the Spanish Ministry of Economy and Competitiveness. J. Parra-Arnau is with the UNESCO Chair in Data Privacy, but the views in this paper are his own and are not necessarily shared by UNESCO., Peer Reviewed

A mobile ad hoc network (MANET) is a set of autonomous mobile devices connected by wireless links in a distributed manner and without a fixed infrastructure. Real-time multimedia services, such as video-streaming over MANETs, offers very promising applications, e.g., two members of a group of tourists who want to share a video transmitted through the MANET they form, a video-streaming service deployed over a MANET where users watch a film, among other examples. On the other hand, social web technologies, where people actively interact online with others through social networks, are leading to a socialization of networks. Information of interaction among users is being used to provide socially-enhanced software. To achieve this, we need to know the strength of the relationship between a given user and each user they interact with. This strength of the relationship can be measured through a concept called tie strength (TS), first introduced by Mark Granovetter in 1973. In this article, we modify our previous proposal named multipath multimedia dynamic source routing (MMDSR) protocol to include a social metric TS in the decisions taken by the forwarding algorithm. We find a trade-off between the quality of service (QoS) and the trust level between users who form the forwarding path in the MANET. Our goal is to increase the trust metric while the QoS is not affected significantly., This work is supported by the Spanish Government through the projects (i) INRISCO
(TEC2014-54335-C4-1-R and TEC2014-54335-C4-3-R); (ii) MAGOS (TEC2017-84197-C4-3-R and TEC2017-
84197-C4-2-R); (iii) the European Regional Development Fund (ERDF); and (iv) the Galician Regional
Government under agreement for funding the Atlantic Research Center for Information and Communication Technologies (AtlantTIC)., Peer Reviewed

Online tracking is the key enabling technology of modern online advertising. In the recently established model of real-time bidding (RTB), the web pages tracked by ad platforms are shared with advertising agencies (also called DSPs), which, in an auction-based system, may bid for user ad impressions. Since tracking data are no longer confined to ad platforms, RTB poses serious risks to privacy, especially with regard to user profiling, a practice that can be conducted at a very low cost by any DSP or related agency, as we reveal here. In this work, we illustrate these privacy risks by examining a data set with the real ad-auctions of a DSP, and show that for at least 55% of the users tracked by this agency, it paid nothing for their browsing data. To mitigate this abuse, we propose a system that regulates the distribution of bid requests (containing user tracking data) to potentially interested bidders, depending on their previous behavior. In our approach, an ad platform restricts the sharing of tracking data by limiting the number of DSPs participating in each auction, thereby leaving unchanged the current RTB architecture and protocols. However, doing so may have an evident impact on the ad platform’s revenue. The proposed system is designed accordingly, to ensure the revenue is maximized while the abuse by DSPs is prevented to a large degree. Experimental results seem to suggest that our system is able to correct misbehaving DSPs, and consequently enhance user privacy., Peer Reviewed

Road safety applications envisaged for vehicular ad hoc networks (VANETs) depend largely on the exchange of messages to deliver information to concerned vehicles. Safety applications as well as inherent VANET characteristics make data dissemination an essential service and a challenging task. We are developing a decentralized efficient solution for broadcast data dissemination through two game-theoretical mechanisms. Besides, VANETs can also include autonomous vehicles (AVs). AVs might represent a revolutionary new paradigm that can be a reality in our cities in the next few years. AVs do not need a driver to work; instead, they should copy a proper human behavior to adapt the driving according to the current circumstances, such as speed limit, pedestrian crossing street or wheather conditions. We will develop an AV software module including artificial intelligence (AI) techniques so that AVs can interact with the dynamic scenario throughout time. Finally, we also will include electrical vehicles (EV) in the VANET, so that special services such as finding and reserving an EV charging station place will be welcome. In addition, we are developing a multimetric geographic routing protocol for VANETs to transmit H.265 video (traffic accident, traffic state, commercial….) over VANETs, Peer Reviewed

© <2019>. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/, k-Anonymous microaggregation is a widespread technique to address the problem of protecting the privacy of the respondents involved beyond the mere suppression of their identifiers, in applications where preserving the utility of the information disclosed is critical. Unfortunately, microaggregation methods with high data utility may impose stringent computational demands when dealing with datasets containing a large number of records and attributes.
This work proposes and analyzes various anonymization methods which draw upon the algebraic-statistical technique of principal component analysis (PCA), in order to effectively reduce the number of attributes processed, that is, the dimension of the multivariate microaggregation problem at hand. By preserving to a high degree the energy of the numerical dataset and carefully choosing the number of dominant components to process, we manage to achieve remarkable reductions in running time and memory usage with negligible impact in information utility. Our methods are readily applicable to high-utility SDC of large-scale datasets with numerical demographic attributes., Peer Reviewed

[EN] Road safety applications envisaged for vehicular ad hoc networks (VANETs) depend largely on the exchange of messages to deliver information to concerned vehicles. Safety applications as well as inherent VANET characteristics make data dissemination an essential service and a challenging task. We are developing a decentralized efficient solution for broadcast data dissemination through two game-theoretical mechanisms. Besides, VANETs can also include autonomous vehicles (AVs). AVs might represent a revolutionary new paradigm that can be a reality in our cities in the next few years. AVs do not need a driver to work; instead, they should copy a proper human behavior to adapt the driving according to the current circumstances, such as speed limit, pedestrian crossing street or wheather conditions. We will develop an AV software module including artificial intelligence (AI) techniques so that AVs can interact with the dynamic scenario throughout time. Finally, we also will include electrical vehicles (EV) in the VANET, so that special services such as finding and reserving an EV charging station place will be welcome. In addition, we are developing a multimetric geographic routing protocol for VANETs to transmit H.265 video (traffic accident, traffic state, commercial….) over VANETs., This work was partly supported by the Spanish Government through the project TEC2014-54335-C4-
1-R INcident monitoRing In Smart COmmunities, QoS and Privacy (INRISCO). Cristian Iza is recipient of a grant from Secretaria Nacional de Educación Superior, Ciencia y Tecnología SENESCYT. Ahmad Mohamad Mezher is a postdoctoral researcher with the Information Security Group (ISG) at the Universitat Politècnica de Catalunya (UPC).