Export results:
Author Title Type [ Year(Asc)]
Filters: First Letter Of Title is S and Author is Cristina Alcaraz  [Clear All Filters]
C. Alcaraz, "Situational Awareness for CPS",
Encyclopedia of Cryptography, Security and Privacy, Springer Berlin Heidelberg, pp. 1--3, 08/2021. DOI
S. Fischer-Hübner, et al., "Stakeholder Perspectives and Requirements on Cybersecurity in Europe",
Journal of Information Security and Applications, vol. 61, no. 102916, Elsevier, 09/2021. DOI (I.F.: 3.872)More..
Impact Factor: 3.872
Journal Citation Reports® Science Edition (Thomson Reuters, 2020)

A. Farao, et al., "SealedGRID: A Secure Interconnection of Technologies for Smart Grid Applications",
14th International Conference on Critical Information Infrastructures Security (CRITIS 2019), vol. 11777, Springer, Cham, pp. 169-175, 12/2019. DOI More..


In recent years, the Smart Grid has increasingly integrated cutting-edge technologies that generate several benefits for all the stakeholders involved, such as a more accurate billing system and enhanced Demand Response procedures. However, this modernization also brings with it diverse cyber security and privacy issues, which sets the necessity for developing a security platform specifically tailored to this scenario. In this paper, we present SealedGRID, which proposes a flexible architecture that provides security services at all levels by implementing Trusted Execution Environments on their devices, together with advanced authentication and authorization mechanisms, as well as privacy preserving techniques. These technologies are presented in depth and a final security analysis is conducted, which highlights the contributions of this project.

C. Alcaraz, "Secure Interconnection of IT-OT Networks in Industry 4.0",
Critical Infrastructure Security and Resilience: Theories, Methods, Tools and Technologies, no. Advanced Sciences and Technologies for Security Applications book series (ASTSA), Springer International Publishing, pp. 201-217, 01/2019. DOI More..


Increasingly, the society is witnessing how today’s industry is adapting the new technologies and communication protocols to offer more optimal and reliable services to end-users, with support for inter-domain communication belonging to diverse critical infrastructures. As a consequence of this technological revolution, interconnection mechanisms are required to offer transparency in the connections and protection in the different application domains, without this implying a significant degradation of the control requirements. Therefore, this book chapter presents a reference architecture for the new Industry 4.0 where the interconnection core is mainly concentrated in the Policy Decision Points (PDP), which can be deployed in high volume data processing and storage technologies such as cloud and fog servers. Each PDP authorizes actions in the field/plant according to a set of factors (entities, context and risks) computed through the existing access control measures, such as RBAC+ABAC+Risk-BAC (Role/Attribute/Risk-Based Access Control, respectively), to establish coordinated and constrained accesses in extreme situations. Part of these actions also includes proactive risk assessment measures to respond to anomalies or intrusive threats in time.

PDF icon alcaraz2019.pdf (3.19 MB)
C. Alcaraz, "Security and Privacy Trends in the Industrial Internet of Things",
Advanced Sciences and Technologies for Security Applications, Springer, 2019. More..
I. Stellios, P. Kotzanikolaou, M. Psarakis, C. Alcaraz, and J. Lopez, "Survey of IoT-enabled Cyberattacks: Assessing Attack Paths to Critical Infrastructures and Services",
IEEE Communications Surveys and Tutorials, vol. 20, issue 4, IEEE, pp. 3453-3495, 07/2018. DOI (I.F.: 22.973)More..


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

Impact Factor: 22.973
Journal Citation Reports® Science Edition (Thomson Reuters, 2018)

C. Alcaraz, and J. Lopez, "Secure Interoperability in Cyber-Physical Systems",
Security Solutions and Applied Cryptography in Smart Grid Communications, IGI Global, USA, IGI Global, pp. 137-158, 2017. DOI More..


Transparency in control transactions under a secure network architecture is a key topic that must be discussed when aspects related to interconnection between heterogeneous cyber-physical systems (CPSs) arise. The interconnection of these systems can be addressed through an enforcement policy system responsible for managing access control according to the contextual conditions. However, this architecture is not always adequate to ensure a rapid interoperability in extreme crisis situations, and can require an interconnection strategy that permits the timely authorized access from anywhere at any time. To do this, a set of interconnection strategies through the Internet must be studied to explore the ability of control entities to connect to the remote CPSs and expedite their operations, taking into account the context conditions. This research constitutes the contribution of this chapter, where a set of control requirements and interoperability properties are identified to discern the most suitable interconnection strategies.

PDF icon 1603.pdf (546.13 KB)
J. E. Rubio, C. Alcaraz, and J. Lopez, "Selecting Privacy Solutions to Prioritise Control in Smart Metering Systems",
The 11th International Conference on Critical Information Infrastructures Security, vol. 10242, pp. 176-188, 2017. More..


The introduction of the Smart Grid brings with it several benefits to society, because its bi-directional communication allows both users and utilities to have better control over energy usage. However, it also has some privacy issues with respect to the privacy of the customers when analysing their consumption data. In this paper we review the main privacy-preserving techniques that have been proposed and compare their efficiency, to accurately select the most appropriate ones for undertaking control operations. Both privacy and performance are essential for the rapid adoption of Smart Grid technologies.

PDF icon 1600.pdf (275.75 KB)
C. Alcaraz, and J. Lopez, "Safeguarding Structural Controllability in Cyber-Physical Control Systems",
The 21st European Symposium on Research in Computer Security (ESORICS 2016), vol. 9879, Springer, pp. 471-489, 2016. More..


Automatic restoration of control wireless networks based on dynamic cyber-physical systems has become a hot topic in recent years, since most of their elements tend to have serious vulnerabilities that may be exploited by attackers. In fact, any exploitation may rapidly extend to the entire control network due to its problem of non-locality, where control properties of a system and its structural controllability can disintegrate over time. Unfortunately, automated self-healing processes may become costly procedures in which the reliability of the strategies and the time-critical of any recovery of the control can become key factors to re-establish the control properties in due time. This operational need is precisely the aim of this paper, in which four reachability-based recovery strategies from a thereotical point of view are proposed so as to find the best option/s in terms of optimization, robustness and complexity. To do this, new definitions related to structural controllability in relation to the type of distribution of the network and its control load capacity are given in this paper, resulting in an interesting practical study.

PDF icon 1598.pdf (606.93 KB)
C. Alcaraz, R. Roman, P. Najera, and J. Lopez, "Security of Industrial Sensor Network-based Remote Substations in the context of the Internet of Things",
Ad Hoc Networks, vol. 11, Elsevier, pp. 1091–1104, 2013. DOI (I.F.: 1.943)More..


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

Impact Factor: 1.943
Journal Citation Reports® Science Edition (Thomson Reuters, 2013)

PDF icon 1752.pdf (1.21 MB)
J. Lopez, C. Alcaraz, and R. Roman, "Smart Control of Operational Threats in Control Substations",
Computers & Security, vol. 38, Elsevier, pp. 14-27, OCT 2013. DOI (I.F.: 1.172)More..


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

Impact Factor: 1.172
Journal Citation Reports® Science Edition (Thomson Reuters, 2013)

PDF icon 1770.pdf (1.58 MB)
C. Alcaraz, E. Etcheves Miciolino, and S. Wolthusen, "Structural Controllability of Networks for Non-Interactive Adversarial Vertex Removal",
8th International Conference on Critical Information Infrastructures Security, vol. 8328, Springer, pp. 120-132, 2013. DOI More..


The problem of controllability of networks arises in a number of different domains, including in critical infrastructure systems where control must be maintained continuously. Recent work by Liu et al. has renewed interest in the seminal work by Lin on structural controllability, providing a graph-theoretical interpretation. This allows the identification of driver nodes capable of forcing the system into a desired state, which implies an obvious target for attackers wishing to disrupt the network control. Several methods for identifying driver nodes exist, but require undesirable computational complexity. In this paper, we therefore investigate the ability to regain or maintain controllability in the presence of adversaries able to remove vertices and implicit edges of the controllability graph. For this we rely on the POWER DOMINATING SET (PDS) formulation for identifying the control structure and study different attack strategies for multiple network models. As the construction of a PDS for a given graph is not unique, we further investigate different strategies for PDS construction, and provide a simulative evaluation.

PDF icon 1810.pdf (625.81 KB)
C. Alcaraz, G. Fernandez, and F. Carvajal, "Security Aspects of SCADA and DCS Environments",
Critical Infrastructure Protection: Information Infrastructure Models, Analysis, and Defense, J. Lopez, S.. Wolthunsen, and R. Setola Eds., Advances in Critical Infrastructure Protection: Information Infrastructure Models, Analysis, and Defense. LNCS 7130. 7130, Springer-Verlag, pp. 120-149, September 2012. More..


SCADA Systems can be seen as a fundamental component in Critical Infrastructures, having an impact in the overall performance of other Critical Infrastructures interconnected. Currently, these systems include in their network designs different types of Information and Communication Technology systems (such as the Internet and wireless technologies), not only to modernize operational processes but also to ensure automation and real-time control. Nonetheless, the use of these new technologies will bring new security challenges, which will have a significant impact on both the business process and home users. Therefore, the main purpose of this Chapter is to address these issues and to analyze the interdependencies of Process Control Systems with ICT systems, to discuss some security aspects and to offer some possible solutions and recommendations.

PDF icon BC2011Alcaraz.pdf (683.38 KB)
C. Alcaraz, J. Lopez, R. Roman, and H-H. Chen, "Selecting key management schemes for WSN applications",
Computers & Security, vol. 31, no. 38, Elsevier, pp. 956–966, Nov 2012. DOI (I.F.: 1.158)More..


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.

Impact Factor: 1.158
Journal Citation Reports® Science Edition (Thomson Reuters, 2012)

PDF icon AlcarazR2012.pdf (326.12 KB)
F.. Siddiqui, S.. Zeadally, C. Alcaraz, and S.. Galvao, "Smart Grid Privacy: Issues and Solutions",
21st International Conference on Computer Communications and Networks (ICCCN), IEEE Computer Society, pp. 1-5, Jul 2012. DOI More..


Migration to an electronically controlled electrical grid to transmit, distribute, and deliver power to consumers has helped enhance the reliability and efficiency of conventional electricity systems. At the same time, this digitally enabled technology called the Smart Grid has brought new challenges to businesses and consumers alike. A key component of such a grid is the smart-metering technology, which is used to collect energy consumption data from homes and transmitting it back to power distributors. A crucial concern is the privacy related to the collection and use of energy consumption data. We present an analysis of Smart Grid privacy issues and discuss recently proposed solutions that can protect the privacy of Smart Grid users.

C. Alcaraz, J. Lopez, J. Zhou, and R. Roman, "Secure SCADA Framework for the Protection of Energy Control Systems",
Concurrency and Computation Practice & Experience, vol. 23, no. 12, John Wiley & Sons, Inc., pp. 1414-1430, Aug 2011. DOI (I.F.: 0.636)More..


Energy distribution systems are becoming increasingly widespread in today’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¯ts of the integration of those new technologies, and also the e®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®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.

Impact Factor: 0.636
Journal Citation Reports® Science Edition (Thomson Reuters, 2011)

PDF icon Alcaraz2011a.pdf (908.82 KB)
R. Roman, J. Lopez, C. Alcaraz, and H. Hwa Chen, "SenseKey - Simplifying the Selection of Key Management Schemes for Sensor Networks",
5th International Symposium on Security and Multimodality in Pervasive Environments (SMPE’11), IEEE, March, 2011. DOI More..


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.

PDF icon Roman11SK.pdf (143.01 KB)
C. Alcaraz, and J. Lopez, "A Security Analysis for Wireless Sensor Mesh Networks in Highly Critical Systems",
IEEE Transactions on Systems, Man, and Cybernetics, Part C: Applications and Reviews, vol. 40, no. 4, IEEE, pp. 419-428, July, 2010. DOI (I.F.: 2.105)More..


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.

Impact Factor: 2.105
Journal Citation Reports® Science Edition (Thomson Reuters, 2010)

PDF icon Alcaraz2010a.pdf (557 KB)
C. Alcaraz, G. Fernandez, R. Roman, A. Balastegui, and J. Lopez, "Secure Management of SCADA Networks",
Novatica, New Trends in Network Management, vol. 9, no. 6, Cepis UPGRADE, pp. 22-28, December, 2008. More..


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

PDF icon Alcaraz2008b.pdf (325.52 KB)
R. Roman, C. Alcaraz, and J. Lopez, "A Survey of Cryptographic Primitives and Implementations for Hardware-Constrained Sensor Network Nodes",
Mobile Networks and Applications, vol. 12, no. 4, Springer, pp. 231-244, August, 2007. DOI (I.F.: 0.586)More..


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.

Impact Factor: 0.586
Journal Citation Reports® Science Edition (Thomson Reuters, 2007)

PDF icon Roman2007.pdf (280.7 KB)
Modify or remove your filters and try again.