Ruben Rios

PostDoctoral Researcher

Edificio de Investigación Ada Byron
C/ Arquitecto Francisco Peñalosa, nº 18
Ampliación Campus de Teatinos. Universidad de Málaga
29071 Málaga (Spain)
Phone: +34-951-952915    Fax: +34-951-952749

Domain of interest and research

  • Privacy-Enhancing Technologies
  • Covert Communication Channels


  • PhD in Computer Science (University of Málaga, Spain, 2014)
  • MSC in Computer Science (University of Málaga, Spain, 2008)
  • BSc in Computer Science (University of Skövde, Sweden, 2007)

Relevant publications

  • R. Rios, J. Cuellar, and J. Lopez, "Probabilistic receiver-location privacy protection in wireless sensor networks", In Information Sciences, vol. 321, Elsevier, pp. 205 - 223, 07/2015. ISI JCR Impact Factor 2015: 3.364 DOI More..


    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.

    Impact Factor: 3.364
    Journal Citation Reports® Science Edition (Thomson Reuters, 2015)

  • R. Rios, J. Cuellar, and J. Lopez, "Robust Probabilistic Fake Packet Injection for Receiver-Location Privacy in WSN", In 17th European Symposium on Research in Computer Security (ESORICS 2012), S. Foresti, M. Yung, and F. Martinelli Eds., LNCS 7459, Springer, pp. 163-180, Sep 2012. DOI More..


    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.

  • R. Rios, and J. Lopez, "(Un)Suitability of Anonymous Communication Systems to WSN", In IEEE Systems Journal, vol. 7, no. 2, IEEE Systems Council, pp. 298 - 310, Jun 2013. ISI JCR Impact Factor 2013: 1.746 DOI More..


    Anonymous communication systems have been extensively studied by the research community to prevent the disclosure of sensitive information from the analysis of individuals’ 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’ 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.

    Impact Factor: 1.746
    Journal Citation Reports® Science Edition (Thomson Reuters, 2013)

  • R. Rios, and J. Lopez, "Exploiting Context-Awareness to Enhance Source-Location Privacy in Wireless Sensor Networks", In The Computer Journal, vol. 54, Oxford University Press, pp. 1603-1615, Sept 2011. ISI JCR Impact Factor 2011: 0.785 DOI More..


    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.

    Impact Factor: 0.785
    Journal Citation Reports® Science Edition (Thomson Reuters, 2011)

  • R. Rios, and J. Lopez, "Analysis of Location Privacy Solutions in Wireless Sensor Networks", In IET Communications, vol. 5, Institution of Engineering and Technology, pp. 2518 - 2532, Nov 2011. DOI More..


    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.

Attended courses and seminars

  • FOSAD 2013: 13th International School on Foundations of Security Analysis and Design. Bertinoro, Italy (2013)
  • Control Systems Security Models, Malaga, Spain (2010)
  • Service Protocol Verification, Malaga, Spain (2010)
  • IPICS 2009: Intensive Programme on Information and Communication Security. Viena, Austria (2010)
  • SWING 2009: 4th Bertinoro PhD School on Security of Wireless Networking. Bertinoro, Italy (2009)
  • Security and Privacy for wireless resource constrained devices, University of Malaga, Spain (2009)
  • SWING 2008: 3rd Bertinoro PhD School on Security of Wireless Networking. Bertinoro, Italy (2008)

Scientific Activities


  • IEEE Member
  • CriptoRed