Cristina Alcaraz - Academia.edu (original) (raw)

Papers by Cristina Alcaraz

International Journal of Information Security

Smart grids (SG) draw the attention of cyber attackers due to their vulnerabilities, which are ca... more Smart grids (SG) draw the attention of cyber attackers due to their vulnerabilities, which are caused by the usage of heterogeneous communication technologies and their distributed nature. While preventing or detecting cyber attacks is a well-studied field of research, making SG more resilient against such threats is a challenging task. This paper provides a classification of the proposed cyber resilience methods against cyber attacks for SG. This classification includes a set of studies that propose cyber-resilient approaches to protect SG and related cyber-physical systems against unforeseen anomalies or deliberate attacks. Each study is briefly analyzed and is associated with the proper cyber resilience technique which is given by the National Institute of Standards and Technology in the Special Publication 800-160. These techniques are also linked to the different states of the typical resilience curve. Consequently, this paper highlights the most critical challenges for achievi...

IEEE Transactions on Industrial Informatics

Computer Security – ESORICS 2020, 2020

Advanced persistent threats (APTs) demand for sophisticated traceability solutions capable of pro... more Advanced persistent threats (APTs) demand for sophisticated traceability solutions capable of providing deep insight into the movements of the attacker through the victim's network at all times. However, traditional intrusion detection systems (IDSs) cannot attain this level of sophistication and more advanced solutions are necessary to cope with these threats. A promising approach in this regard is Opinion Dynamics, which has proven to work effectively both theoretically and in realistic scenarios. On this basis, we revisit this consensus-based approach in an attempt to generalize a detection framework for the traceability of APTs under a realistic attacker model. Once the framework is defined, we use it to develop a distributed detection technique based on clustering, which contrasts with the consensus technique applied by Opinion Dynamics and interestingly returns comparable results.

The introduction of the Smart Grid brings with it several benefits to society, because its bi-dir... 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.

Advanced Sciences and Technologies for Security Applications, 2019

Increasingly, the society is witnessing how today's industry is adapting the new technologies and... 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.

Lecture Notes in Computer Science, 2019

Opinion Dynamics poses a novel technique to accurately locate the patterns of an advanced attack ... more Opinion Dynamics poses a novel technique to accurately locate the patterns of an advanced attack against an industrial infrastructure, compared to traditional intrusion detection systems. This distributed solution provides profitable information to identify the most affected areas within the network, which can be leveraged to design and deploy tailored response mechanisms that ensure the continuity of the service. In this work, we base on this multi-agent collaborative approach to propose a response technique that permits the secure delivery of messages across the network. For such goal, our contribution is twofold: firstly, we redefine the existing algorithm to assess not only the compromise of nodes, but also the security and quality of service of communication links; secondly, we develop a routing protocol that prioritizes the secure paths throughout the topology considering the information obtained from the detection system.

Proceedings of the 13th International Joint Conference on e-Business and Telecommunications, 2016

Increasingly, automatic restoration is an indispensable security measure in control systems (e.g.... more Increasingly, automatic restoration is an indispensable security measure in control systems (e.g. those used in critical infrastructure sectors) due to the importance of ensuring the functionality of monitoring infrastructures. Modernizing the interconnection of control systems to provide interoperability between different networks, at a low cost, is also a critical requirement in control systems. However, automated recovery mechanisms are currently costly, and ensuring interoperability particularly at a low cost remains a topic of scientific challenge. This is the gap we seek to address in this paper. More specifically, we propose a restoration model for interconnected contexts, taking into account the theory of supernode and structural controllability, as well as the recommendations given by the IEC-62351-8 standard (which are mainly based on the implementation of a role-based access control system).

Journal of Parallel and Distributed Computing, 2020

Industry 4.0 technological expansion and the multiple accesses to the diverse Smart Grid domains ... more Industry 4.0 technological expansion and the multiple accesses to the diverse Smart Grid domains (power networks, control systems, market, customer premises) entail the need to provide efficient interconnection mechanisms with connection from anywhere, at any time and in anyhow. However, this type of requirement should not only consist in imposing interoperability solutions between entities and domains, but also in searching the way to justify and trace connections (how, when, where, who) for future governance or auditing actions. This paper, therefore, presents a three layer-based interconnection architecture and several interconnection strategies, all of them adapting the traditional policy decision and enforcement approaches together with the blockchain technology to manage reliable and secure connections among entities, processes and critical resources. With this architecture in mind, the paper also analyzes the coupling level of the blockchain technology, and explores which interconnection strategy is more suitable for Smart Grid domains and their control systems.

Journal of Computer Security, 2019

In recent years, Advanced Persistent Threats (APTs) have become a major issue for critical infras... more In recent years, Advanced Persistent Threats (APTs) have become a major issue for critical infrastructures that are increasingly integrating modern IT technologies. This requires the development of advanced cyber-security services that can holistically detect and trace these attacks, beyond traditional solutions. In this sense, Opinion Dynamics has been proven as an effective solution, as they can locate the most affected areas within the industrial network. With this information, it is possible to put in place accurate response techniques to limit the impact of attacks on the infrastructure. In this paper, we analyze the applicability of Opinion Dynamics to trace an APT throughout its entire life cycle, by correlating different anomalies over time and accounting for the persistence of threats and the criticality of resources. Moreover, we run various experiments with this novel technique over a testbed that models a real control system, thereby assessing its effectiveness in an actual industrial scenario.

Computer Security – ESORICS 2016, 2016

Automatic restoration of control wireless networks based on dynamic cyber-physical systems has be... 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 theoretical 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.

Lecture Notes in Computer Science, 2015

The notion of controllability, informally the ability to force a system into a desired state in a... more The notion of controllability, informally the ability to force a system into a desired state in a finite time or number of steps, is most closely associated with control systems such as those used to maintain power networks and other critical infrastructures, but has wider relevance in distributed systems. It is clearly highly desirable to understand under which conditions attackers may be able to disrupt legitimate control, or to force overriding controllability themselves. Following recent results by Liu et al., there has been considerable interest also in graphtheoretical interpretation of Kalman controllability originally introduced by Lin, structural controllability. This permits the identification of sets of driver nodes with the desired state-forcing property, but determining such nodes is a W [2]-hard problem. To extract these nodes and represent the control relation, here we apply the POWER DOMINATING SET problem and investigate the effects of targeted iterative multiple-vertex removal. We report the impact that different attack strategies with multiple edge and vertex removal will have, based on underlying noncomplete graphs, with an emphasis on power-law random graphs with different degree sequences.

IFIP Advances in Information and Communication Technology, 2014

Fundamental problems in control systems theory are controllability and observability, and designi... more Fundamental problems in control systems theory are controllability and observability, and designing control systems so that these properties are satisfied or approximated sufficiently. However, it is prudent to assume that an attacker will not only be able to subvert measurements but also control the system. Moreover, an advanced adversary with an understanding of the control system may seek to take over control of the entire system or parts thereof, or deny the legitimate operator this capability. The effectiveness of such attacks has been demonstrated in previous work. Indeed, these attacks cannot be ruled out given the likely existence of unknown vulnerabilities, increasing connectivity of nominally air-gapped systems and supply chain issues. The ability to rapidly recover control after an attack has been initiated and to detect an adversary's presence is, therefore, critical. This paper focuses on the problem of structural controllability, which has recently attracted substantial attention through the equivalent problem of the power dominating set introduced in the context of electrical power network control. However, these problems are known to be N P-hard with poor approximability. Given their relevance to many networks, especially power networks, this paper studies strategies for the efficient restoration of controllability following attacks and attacker-defender interactions in power-law networks.

Lecture Notes in Computer Science

Critical Infrastructures are complex and highly interconnected systems that are crucial for the w... more 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.

Key Management Schemes (KMS) are a very important security mechanism for Wireless Sensor Networks... 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.

Technological convergence in control and acquisition tasks in critical control systems has become... more Technological convergence in control and acquisition tasks in critical control systems has become a cutting-edge topic in recent years. Modernization not only offers a way of increasing operational performance but it also infers greater security issues and associated risks. Although there currently is an important diversity of studies dealing with aspects related to the adaptation of new technologies in the control processes, it is also necessary to formally analyze problems and challenges when such technologies and information systems are being adopted. For this reason, in this paper we formally analyze how the different domains of a control system using new technologies could have an influence on each other, impacting sooner or later on the final performance of the system or critical systems. As a result, five requirements of control have been identified with the objective of proposing a new set of operational requirements that ensure a suitable trade-off between performance and security.

Lecture Notes in Computer Science

Lecture Notes in Computer Science, 2006

and information technology facilities, networks, services and assets. 1. CI[I]P and Wireless Sens... more and information technology facilities, networks, services and assets. 1. CI[I]P and Wireless Sensor Networks 2. CRISIS 4. Conclusions 3. KMS CRISIS Guidelines 1. CI[I]P and Wireless Sensor Networks 2. CRISIS 4. Conclusions 3. KMS CRISIS Guidelines 1. CI[I]P and Wireless Sensor Networks 2. CRISIS 4. Conclusions 3. KMS CRISIS Guidelines 1. CI[I]P and Wireless Sensor Networks 2. CRISIS 4. Conclusions 3. KMS CRISIS Guidelines Applying Key Infrastructures for Sensor Networks Applying Key Infrastructures for Sensor Networks in CIP / CIIP in CIP / CIIP Scenarios Scenarios Key Infrastructures Key Infrastructures-Concept Concept • Trust Management Model-Advanced Authentication Services • Network Designer must choose Key Management System (KMS) Key Management System (KMS) 1. CI[I]P and Wireless Sensor Networks 2. CRISIS 4. Conclusions 3. KMS CRISIS Guidelines

Lecture Notes in Computer Science, 2013

Critical Infrastructure Protection (CIP) faces increasing challenges in number and in sophisticat... more Critical Infrastructure Protection (CIP) faces increasing challenges in number and in sophistication, which makes vital to provide new forms of protection to face every day's threats. In order to make such protection holistic, covering all the needs of the systems from the point of view of security, prevention aspects and situational awareness should be considered. Researchers and Institutions stress the need of providing intelligent and automatic solutions for protection, calling our attention to the need of providing Intrusion Detection Systems (IDS) with intelligent active reaction capabilities. In this paper, we support the need of automating the processes implicated in the IDS solutions of the critical infrastructures and theorize that the introduction of Machine Learning (ML) techniques in IDS will be helpful for implementing automatic adaptable solutions capable of adjusting to new situations and timely reacting in the face of threats and anomalies. To this end, we study the different levels of automation that the IDS can implement, and outline a methodology to endow critical scenarios with preventive automation. Finally, we analyze current solutions presented in the literature and contrast them against the proposed methodology.

Lecture Notes in Computer Science, 2013

Sparse graphs to represent main critical infrastructures Connectivity probability of p k = 0.3 fo... more Sparse graphs to represent main critical infrastructures Connectivity probability of p k = 0.3 for ER/WS, d − = 2 for BA for α 3,

Mobile Networks and Applications, 2007

In a wireless sensor network environment, a sensor node is extremely constrained in terms of hard... 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.

International Journal of Information Security

Smart grids (SG) draw the attention of cyber attackers due to their vulnerabilities, which are ca... more Smart grids (SG) draw the attention of cyber attackers due to their vulnerabilities, which are caused by the usage of heterogeneous communication technologies and their distributed nature. While preventing or detecting cyber attacks is a well-studied field of research, making SG more resilient against such threats is a challenging task. This paper provides a classification of the proposed cyber resilience methods against cyber attacks for SG. This classification includes a set of studies that propose cyber-resilient approaches to protect SG and related cyber-physical systems against unforeseen anomalies or deliberate attacks. Each study is briefly analyzed and is associated with the proper cyber resilience technique which is given by the National Institute of Standards and Technology in the Special Publication 800-160. These techniques are also linked to the different states of the typical resilience curve. Consequently, this paper highlights the most critical challenges for achievi...

IEEE Transactions on Industrial Informatics

Computer Security – ESORICS 2020, 2020

Advanced persistent threats (APTs) demand for sophisticated traceability solutions capable of pro... more Advanced persistent threats (APTs) demand for sophisticated traceability solutions capable of providing deep insight into the movements of the attacker through the victim's network at all times. However, traditional intrusion detection systems (IDSs) cannot attain this level of sophistication and more advanced solutions are necessary to cope with these threats. A promising approach in this regard is Opinion Dynamics, which has proven to work effectively both theoretically and in realistic scenarios. On this basis, we revisit this consensus-based approach in an attempt to generalize a detection framework for the traceability of APTs under a realistic attacker model. Once the framework is defined, we use it to develop a distributed detection technique based on clustering, which contrasts with the consensus technique applied by Opinion Dynamics and interestingly returns comparable results.

The introduction of the Smart Grid brings with it several benefits to society, because its bi-dir... 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.

Advanced Sciences and Technologies for Security Applications, 2019

Increasingly, the society is witnessing how today's industry is adapting the new technologies and... 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.

Lecture Notes in Computer Science, 2019

Opinion Dynamics poses a novel technique to accurately locate the patterns of an advanced attack ... more Opinion Dynamics poses a novel technique to accurately locate the patterns of an advanced attack against an industrial infrastructure, compared to traditional intrusion detection systems. This distributed solution provides profitable information to identify the most affected areas within the network, which can be leveraged to design and deploy tailored response mechanisms that ensure the continuity of the service. In this work, we base on this multi-agent collaborative approach to propose a response technique that permits the secure delivery of messages across the network. For such goal, our contribution is twofold: firstly, we redefine the existing algorithm to assess not only the compromise of nodes, but also the security and quality of service of communication links; secondly, we develop a routing protocol that prioritizes the secure paths throughout the topology considering the information obtained from the detection system.

Proceedings of the 13th International Joint Conference on e-Business and Telecommunications, 2016

Increasingly, automatic restoration is an indispensable security measure in control systems (e.g.... more Increasingly, automatic restoration is an indispensable security measure in control systems (e.g. those used in critical infrastructure sectors) due to the importance of ensuring the functionality of monitoring infrastructures. Modernizing the interconnection of control systems to provide interoperability between different networks, at a low cost, is also a critical requirement in control systems. However, automated recovery mechanisms are currently costly, and ensuring interoperability particularly at a low cost remains a topic of scientific challenge. This is the gap we seek to address in this paper. More specifically, we propose a restoration model for interconnected contexts, taking into account the theory of supernode and structural controllability, as well as the recommendations given by the IEC-62351-8 standard (which are mainly based on the implementation of a role-based access control system).

Journal of Parallel and Distributed Computing, 2020

Industry 4.0 technological expansion and the multiple accesses to the diverse Smart Grid domains ... more Industry 4.0 technological expansion and the multiple accesses to the diverse Smart Grid domains (power networks, control systems, market, customer premises) entail the need to provide efficient interconnection mechanisms with connection from anywhere, at any time and in anyhow. However, this type of requirement should not only consist in imposing interoperability solutions between entities and domains, but also in searching the way to justify and trace connections (how, when, where, who) for future governance or auditing actions. This paper, therefore, presents a three layer-based interconnection architecture and several interconnection strategies, all of them adapting the traditional policy decision and enforcement approaches together with the blockchain technology to manage reliable and secure connections among entities, processes and critical resources. With this architecture in mind, the paper also analyzes the coupling level of the blockchain technology, and explores which interconnection strategy is more suitable for Smart Grid domains and their control systems.

Journal of Computer Security, 2019

In recent years, Advanced Persistent Threats (APTs) have become a major issue for critical infras... more In recent years, Advanced Persistent Threats (APTs) have become a major issue for critical infrastructures that are increasingly integrating modern IT technologies. This requires the development of advanced cyber-security services that can holistically detect and trace these attacks, beyond traditional solutions. In this sense, Opinion Dynamics has been proven as an effective solution, as they can locate the most affected areas within the industrial network. With this information, it is possible to put in place accurate response techniques to limit the impact of attacks on the infrastructure. In this paper, we analyze the applicability of Opinion Dynamics to trace an APT throughout its entire life cycle, by correlating different anomalies over time and accounting for the persistence of threats and the criticality of resources. Moreover, we run various experiments with this novel technique over a testbed that models a real control system, thereby assessing its effectiveness in an actual industrial scenario.

Computer Security – ESORICS 2016, 2016

Automatic restoration of control wireless networks based on dynamic cyber-physical systems has be... 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 theoretical 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.

Lecture Notes in Computer Science, 2015

The notion of controllability, informally the ability to force a system into a desired state in a... more The notion of controllability, informally the ability to force a system into a desired state in a finite time or number of steps, is most closely associated with control systems such as those used to maintain power networks and other critical infrastructures, but has wider relevance in distributed systems. It is clearly highly desirable to understand under which conditions attackers may be able to disrupt legitimate control, or to force overriding controllability themselves. Following recent results by Liu et al., there has been considerable interest also in graphtheoretical interpretation of Kalman controllability originally introduced by Lin, structural controllability. This permits the identification of sets of driver nodes with the desired state-forcing property, but determining such nodes is a W [2]-hard problem. To extract these nodes and represent the control relation, here we apply the POWER DOMINATING SET problem and investigate the effects of targeted iterative multiple-vertex removal. We report the impact that different attack strategies with multiple edge and vertex removal will have, based on underlying noncomplete graphs, with an emphasis on power-law random graphs with different degree sequences.

IFIP Advances in Information and Communication Technology, 2014

Fundamental problems in control systems theory are controllability and observability, and designi... more Fundamental problems in control systems theory are controllability and observability, and designing control systems so that these properties are satisfied or approximated sufficiently. However, it is prudent to assume that an attacker will not only be able to subvert measurements but also control the system. Moreover, an advanced adversary with an understanding of the control system may seek to take over control of the entire system or parts thereof, or deny the legitimate operator this capability. The effectiveness of such attacks has been demonstrated in previous work. Indeed, these attacks cannot be ruled out given the likely existence of unknown vulnerabilities, increasing connectivity of nominally air-gapped systems and supply chain issues. The ability to rapidly recover control after an attack has been initiated and to detect an adversary's presence is, therefore, critical. This paper focuses on the problem of structural controllability, which has recently attracted substantial attention through the equivalent problem of the power dominating set introduced in the context of electrical power network control. However, these problems are known to be N P-hard with poor approximability. Given their relevance to many networks, especially power networks, this paper studies strategies for the efficient restoration of controllability following attacks and attacker-defender interactions in power-law networks.

Lecture Notes in Computer Science

Critical Infrastructures are complex and highly interconnected systems that are crucial for the w... more 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.

Key Management Schemes (KMS) are a very important security mechanism for Wireless Sensor Networks... 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.

Technological convergence in control and acquisition tasks in critical control systems has become... more Technological convergence in control and acquisition tasks in critical control systems has become a cutting-edge topic in recent years. Modernization not only offers a way of increasing operational performance but it also infers greater security issues and associated risks. Although there currently is an important diversity of studies dealing with aspects related to the adaptation of new technologies in the control processes, it is also necessary to formally analyze problems and challenges when such technologies and information systems are being adopted. For this reason, in this paper we formally analyze how the different domains of a control system using new technologies could have an influence on each other, impacting sooner or later on the final performance of the system or critical systems. As a result, five requirements of control have been identified with the objective of proposing a new set of operational requirements that ensure a suitable trade-off between performance and security.

Lecture Notes in Computer Science

Lecture Notes in Computer Science, 2006

and information technology facilities, networks, services and assets. 1. CI[I]P and Wireless Sens... more and information technology facilities, networks, services and assets. 1. CI[I]P and Wireless Sensor Networks 2. CRISIS 4. Conclusions 3. KMS CRISIS Guidelines 1. CI[I]P and Wireless Sensor Networks 2. CRISIS 4. Conclusions 3. KMS CRISIS Guidelines 1. CI[I]P and Wireless Sensor Networks 2. CRISIS 4. Conclusions 3. KMS CRISIS Guidelines 1. CI[I]P and Wireless Sensor Networks 2. CRISIS 4. Conclusions 3. KMS CRISIS Guidelines Applying Key Infrastructures for Sensor Networks Applying Key Infrastructures for Sensor Networks in CIP / CIIP in CIP / CIIP Scenarios Scenarios Key Infrastructures Key Infrastructures-Concept Concept • Trust Management Model-Advanced Authentication Services • Network Designer must choose Key Management System (KMS) Key Management System (KMS) 1. CI[I]P and Wireless Sensor Networks 2. CRISIS 4. Conclusions 3. KMS CRISIS Guidelines

Lecture Notes in Computer Science, 2013

Critical Infrastructure Protection (CIP) faces increasing challenges in number and in sophisticat... more Critical Infrastructure Protection (CIP) faces increasing challenges in number and in sophistication, which makes vital to provide new forms of protection to face every day's threats. In order to make such protection holistic, covering all the needs of the systems from the point of view of security, prevention aspects and situational awareness should be considered. Researchers and Institutions stress the need of providing intelligent and automatic solutions for protection, calling our attention to the need of providing Intrusion Detection Systems (IDS) with intelligent active reaction capabilities. In this paper, we support the need of automating the processes implicated in the IDS solutions of the critical infrastructures and theorize that the introduction of Machine Learning (ML) techniques in IDS will be helpful for implementing automatic adaptable solutions capable of adjusting to new situations and timely reacting in the face of threats and anomalies. To this end, we study the different levels of automation that the IDS can implement, and outline a methodology to endow critical scenarios with preventive automation. Finally, we analyze current solutions presented in the literature and contrast them against the proposed methodology.

Lecture Notes in Computer Science, 2013

Sparse graphs to represent main critical infrastructures Connectivity probability of p k = 0.3 fo... more Sparse graphs to represent main critical infrastructures Connectivity probability of p k = 0.3 for ER/WS, d − = 2 for BA for α 3,

Mobile Networks and Applications, 2007

In a wireless sensor network environment, a sensor node is extremely constrained in terms of hard... 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.