Olga Leon - Academia.edu (original) (raw)

Papers by Olga Leon

Research paper thumbnail of On the revocation of malicious users in anonymous and non-traceable VANETs

For the proper performance of Vehicular Ad-hoc NETworks (VANETs) it is essential to protect the s... more For the proper performance of Vehicular Ad-hoc NETworks (VANETs) it is essential to protect the service against malicious nodes aiming at disrupting the proper operation by injecting fake, invalid data into the network. It is common to define a traditional identity-based authentication for vehicles, which are loaded with individual credentials. However, the use of these credentials in VANETs may allow vehicle tracking and thus violate users' privacy, a risk that can be overcome by means of anonymity schemes. This comes at the expenses, however, of on the one hand preventing VANET authorities from identifying malicious users and revoking them from the network, or on the other hand to avoid anonymity of users in front of the CA thus to allow their revocation. In this work, we describe a novel revocation scheme that is able to track and revoke specific users only after a number of complaints have been received while otherwise guaranteeing vehicle's anonymity.

Research paper thumbnail of A Cognitive-Radio-Based Method for Improving Availability in Body Sensor Networks

International Journal of Distributed Sensor Networks, 2015

One of the main threats to body sensor networks (BSNs) is Denial of Service attacks that disrupt ... more One of the main threats to body sensor networks (BSNs) is Denial of Service attacks that disrupt communications used to transmit patients’ health data. The application of cognitive radio (CR) technology into BSNs can mitigate such a threat and improve network availability, by allowing network nodes to cooperatively agree on a new radio channel whenever the quality of the channel being in use decreases. However, the cooperative spectrum sensing mechanisms used by CRs should also be protected to prevent an attacker from predicting the new channel of operation. In this work, we present a lightweight and robust mechanism that appropriately secures the channel selection process while minimizing resources consumption, thus being suited for resource constrained devices such as body sensor nodes. The proposed method has been analyzed in terms of energy consumption and transmission overhead and it has been shown that it outperforms existing cryptographic approaches.

Research paper thumbnail of Providing k-anonymity and revocation in ubiquitous VANETs

Ad Hoc Networks, 2016

Vehicular ad hoc networks (VANETs) is considered a milestone in improving the safety and efficien... more Vehicular ad hoc networks (VANETs) is considered a milestone in improving the safety and efficiency in transportation. Nevertheless, when information from the vehicular communications is combined with data from the cloud, it also introduces some privacy risks by making it easier to track the physical location of vehicles. For this reason, to guarantee the proper performance of a VANET it is essential to protect the service against malicious users aiming at disrupting the proper operation of the network. Current researches usually define a traditional identity-based authentication for nodes, which are loaded with individual credentials. However, the use of these credentials in VANETs without any security mechanism enables vehicle tracking and therefore, violate users' privacy, a risk that may be overcome by means of appropriate anonymity schemes. This comes at the cost, however, of on the one hand preventing VANET centralized authorities from identifying malicious users and revoking them from the network, or on the other hand to avoid complete anonymity of nodes in front of the CA thus to allow their revocation. In this paper, a novel revocation scheme that is able to track and revoke specific malicious users only after a number of complaints have been received while otherwise guaranteeing node's k-anonymity is described. The proper performance of these mechanisms has been widely evaluated with NS-2 simulator and an analytical model validated with scripts. The results show that presented work is a promising approach in order to increase privacy protection while allowing revocation with little extra costs.

Research paper thumbnail of Robust detection of primary user emulation attacks in IEEE 802.22 networks

Proceedings of the 4th International Conference on Cognitive Radio and Advanced Spectrum Management, 2011

Research paper thumbnail of Towards a Cooperative Intrusion Detection System for Cognitive Radio Networks

Lecture Notes in Computer Science, 2011

Cognitive Radio Networks (CRNs) arise as a promising solution to the scarcity of spectrum. By mea... more Cognitive Radio Networks (CRNs) arise as a promising solution to the scarcity of spectrum. By means of cooperation and smart decisions influenced by previous knowledge, CRNs are able to detect and profit from the best spectrum opportunities without interfering primary licensed users. However, besides the well-known attacks to wireless networks, new attacks threat this type of networks. In this paper we analyze these threats and propose a set of intrusion detection modules targeted to detect them. Provided method will allow a CRN to identify attack sources and types of attacks, and to properly react against them.

Research paper thumbnail of Privacy risk analysis in the IoT domain

2018 Global Internet of Things Summit (GIoTS), 2018

Most IoT systems are using or exchanging user related information between system components. This... more Most IoT systems are using or exchanging user related information between system components. This means that privacy is a key factor in these systems. Privacy, both in terms of not allowing unauthorized access to information, but also in terms of handling sensitive information correctly and responsibly. As IoT systems typically are comprised of many software and hardware distributed components, ensuring privacy is a challenging task. This paper proposes a risk rating methodology for identifying and rating privacy risks, and demonstrates how to apply this methodology in an IoT use case set in the context of the EU H2020 BIG IoT project. It is also demonstrated how to handle the results of the risk rating methodology.

Research paper thumbnail of Modeling the Lion Attack in Cognitive Radio Networks

Eurasip Journal on Wireless Communications and Networking, 2011

Cognitive radio is a promising technology aiming to improve the utilization of the radio electrom... more Cognitive radio is a promising technology aiming to improve the utilization of the radio electromagnetic spectrum. A cognitive radio is a smart device which runs radio applications software to perform signal processing. The use of this software enables the device to sense and understand its environment and actively change its mode of operation based on its observations. Unfortunately, this solution entails new security challenges. In this paper, we present a cross-layer attack to TCP connections in cognitive radio networks, analyze its impact on TCP throughput via analytical model and simulation, and propose potential countermeasures to mitigate it.

Research paper thumbnail of The TAMESIS Project: Enabling Technologies for the Health Status Monitoring and Secure Exchange of Clinical Records

2013 Seventh International Conference on Complex, Intelligent, and Software Intensive Systems (Cisis), 2013

ABSTRACT Personal Health Systems (PHS) allow to move the point of care from hospitals to the pati... more ABSTRACT Personal Health Systems (PHS) allow to move the point of care from hospitals to the patient's home. Moreover, a PHS usually handles much more information and provides more appropriate diagnostic and personalized treatments to individuals. In this paper, we present the objectives, structure and expected innovations of the TAMESIS project. TAMESIS aims to contribute in advancing the state of the art of some of the technologies needed for the development of Personal Health Systems. Specifically, we propose techniques for preventing denial of service, sensor node malfunctioning and traffic injection. In addition, we explore a protocol that makes use of mobile agents for the exchange of medical records between networked databases. As a novel aspect, the protocol will not only support bilateral agreements, already existing in the literature, but multilateral agreements. In reference to clinical data, is critical to preserve the privacy and intimacy of patients. Thus, the data, at the time of being collected as for when it is exchanged, should be processed so as to avoid leakage of information that is not strictly necessary for the parties to fulfill their task correctly. A privacy metric suitable for PHS, and the incorporation of mechanisms needed for privacy and intimacy are also key objectives of this project. Finally, usability aspects of all the system interfaces will be considered.

Research paper thumbnail of A new cross-layer attack to TCP in cognitive radio networks

2009 Second International Workshop on Cross Layer Design, 2009

... Failure in the retransmission of a lost segment due to persistence of the handoff, can even l... more ... Failure in the retransmission of a lost segment due to persistence of the handoff, can even lead to a worse situation in which the sender remains inactive for a long period of time, since the retransmission timer backs off (doubling its value) for each unsuccessful attempt. ...

Research paper thumbnail of Securing cognitive radio networks

International Journal of Communication Systems, 2010

Cognitive radio is a promising technology aiming to improve the utilization of the radio electrom... more Cognitive radio is a promising technology aiming to improve the utilization of the radio electromagnetic spectrum. A cognitive radio device uses general purpose computer processors that run radio applications software to perform signal processing. The use of this software enables the device to sense and understand its environment and actively change its mode of operation based on its observations. Unfortunately, this solution entails new security challenges. Our objective in this paper is to analyze the security issues of the main recent developments and architectures of cognitive radio networks. We present vulnerabilities inherent to those systems, identify novel types of abuse, classify attacks, and analyze their impact on the operation of cognitive radio‐based systems. Moreover, we discuss and propose security solutions to mitigate such threats. Copyright © 2010 John Wiley & Sons, Ltd.

Research paper thumbnail of The TAMESIS Project: Enabling Technologies for the Health Status Monitoring and Secure Exchange of Clinical Records

2013 Seventh International Conference on Complex, Intelligent, and Software Intensive Systems (Cisis), 2013

ABSTRACT Personal Health Systems (PHS) allow to move the point of care from hospitals to the pati... more ABSTRACT Personal Health Systems (PHS) allow to move the point of care from hospitals to the patient's home. Moreover, a PHS usually handles much more information and provides more appropriate diagnostic and personalized treatments to individuals. In this paper, we present the objectives, structure and expected innovations of the TAMESIS project. TAMESIS aims to contribute in advancing the state of the art of some of the technologies needed for the development of Personal Health Systems. Specifically, we propose techniques for preventing denial of service, sensor node malfunctioning and traffic injection. In addition, we explore a protocol that makes use of mobile agents for the exchange of medical records between networked databases. As a novel aspect, the protocol will not only support bilateral agreements, already existing in the literature, but multilateral agreements. In reference to clinical data, is critical to preserve the privacy and intimacy of patients. Thus, the data, at the time of being collected as for when it is exchanged, should be processed so as to avoid leakage of information that is not strictly necessary for the parties to fulfill their task correctly. A privacy metric suitable for PHS, and the incorporation of mechanisms needed for privacy and intimacy are also key objectives of this project. Finally, usability aspects of all the system interfaces will be considered.

Research paper thumbnail of On the revocation of malicious users in anonymous and non-traceable VANETs

For the proper performance of Vehicular Ad-hoc NETworks (VANETs) it is essential to protect the s... more For the proper performance of Vehicular Ad-hoc NETworks (VANETs) it is essential to protect the service against malicious nodes aiming at disrupting the proper operation by injecting fake, invalid data into the network. It is common to define a traditional identity-based authentication for vehicles, which are loaded with individual credentials. However, the use of these credentials in VANETs may allow vehicle tracking and thus violate users' privacy, a risk that can be overcome by means of anonymity schemes. This comes at the expenses, however, of on the one hand preventing VANET authorities from identifying malicious users and revoking them from the network, or on the other hand to avoid anonymity of users in front of the CA thus to allow their revocation. In this work, we describe a novel revocation scheme that is able to track and revoke specific users only after a number of complaints have been received while otherwise guaranteeing vehicle's anonymity.

Research paper thumbnail of A Cognitive-Radio-Based Method for Improving Availability in Body Sensor Networks

International Journal of Distributed Sensor Networks, 2015

One of the main threats to body sensor networks (BSNs) is Denial of Service attacks that disrupt ... more One of the main threats to body sensor networks (BSNs) is Denial of Service attacks that disrupt communications used to transmit patients’ health data. The application of cognitive radio (CR) technology into BSNs can mitigate such a threat and improve network availability, by allowing network nodes to cooperatively agree on a new radio channel whenever the quality of the channel being in use decreases. However, the cooperative spectrum sensing mechanisms used by CRs should also be protected to prevent an attacker from predicting the new channel of operation. In this work, we present a lightweight and robust mechanism that appropriately secures the channel selection process while minimizing resources consumption, thus being suited for resource constrained devices such as body sensor nodes. The proposed method has been analyzed in terms of energy consumption and transmission overhead and it has been shown that it outperforms existing cryptographic approaches.

Research paper thumbnail of Providing k-anonymity and revocation in ubiquitous VANETs

Ad Hoc Networks, 2016

Vehicular ad hoc networks (VANETs) is considered a milestone in improving the safety and efficien... more Vehicular ad hoc networks (VANETs) is considered a milestone in improving the safety and efficiency in transportation. Nevertheless, when information from the vehicular communications is combined with data from the cloud, it also introduces some privacy risks by making it easier to track the physical location of vehicles. For this reason, to guarantee the proper performance of a VANET it is essential to protect the service against malicious users aiming at disrupting the proper operation of the network. Current researches usually define a traditional identity-based authentication for nodes, which are loaded with individual credentials. However, the use of these credentials in VANETs without any security mechanism enables vehicle tracking and therefore, violate users' privacy, a risk that may be overcome by means of appropriate anonymity schemes. This comes at the cost, however, of on the one hand preventing VANET centralized authorities from identifying malicious users and revoking them from the network, or on the other hand to avoid complete anonymity of nodes in front of the CA thus to allow their revocation. In this paper, a novel revocation scheme that is able to track and revoke specific malicious users only after a number of complaints have been received while otherwise guaranteeing node's k-anonymity is described. The proper performance of these mechanisms has been widely evaluated with NS-2 simulator and an analytical model validated with scripts. The results show that presented work is a promising approach in order to increase privacy protection while allowing revocation with little extra costs.

Research paper thumbnail of Robust detection of primary user emulation attacks in IEEE 802.22 networks

Proceedings of the 4th International Conference on Cognitive Radio and Advanced Spectrum Management, 2011

Research paper thumbnail of Towards a Cooperative Intrusion Detection System for Cognitive Radio Networks

Lecture Notes in Computer Science, 2011

Cognitive Radio Networks (CRNs) arise as a promising solution to the scarcity of spectrum. By mea... more Cognitive Radio Networks (CRNs) arise as a promising solution to the scarcity of spectrum. By means of cooperation and smart decisions influenced by previous knowledge, CRNs are able to detect and profit from the best spectrum opportunities without interfering primary licensed users. However, besides the well-known attacks to wireless networks, new attacks threat this type of networks. In this paper we analyze these threats and propose a set of intrusion detection modules targeted to detect them. Provided method will allow a CRN to identify attack sources and types of attacks, and to properly react against them.

Research paper thumbnail of Privacy risk analysis in the IoT domain

2018 Global Internet of Things Summit (GIoTS), 2018

Most IoT systems are using or exchanging user related information between system components. This... more Most IoT systems are using or exchanging user related information between system components. This means that privacy is a key factor in these systems. Privacy, both in terms of not allowing unauthorized access to information, but also in terms of handling sensitive information correctly and responsibly. As IoT systems typically are comprised of many software and hardware distributed components, ensuring privacy is a challenging task. This paper proposes a risk rating methodology for identifying and rating privacy risks, and demonstrates how to apply this methodology in an IoT use case set in the context of the EU H2020 BIG IoT project. It is also demonstrated how to handle the results of the risk rating methodology.

Research paper thumbnail of Modeling the Lion Attack in Cognitive Radio Networks

Eurasip Journal on Wireless Communications and Networking, 2011

Cognitive radio is a promising technology aiming to improve the utilization of the radio electrom... more Cognitive radio is a promising technology aiming to improve the utilization of the radio electromagnetic spectrum. A cognitive radio is a smart device which runs radio applications software to perform signal processing. The use of this software enables the device to sense and understand its environment and actively change its mode of operation based on its observations. Unfortunately, this solution entails new security challenges. In this paper, we present a cross-layer attack to TCP connections in cognitive radio networks, analyze its impact on TCP throughput via analytical model and simulation, and propose potential countermeasures to mitigate it.

Research paper thumbnail of The TAMESIS Project: Enabling Technologies for the Health Status Monitoring and Secure Exchange of Clinical Records

2013 Seventh International Conference on Complex, Intelligent, and Software Intensive Systems (Cisis), 2013

ABSTRACT Personal Health Systems (PHS) allow to move the point of care from hospitals to the pati... more ABSTRACT Personal Health Systems (PHS) allow to move the point of care from hospitals to the patient's home. Moreover, a PHS usually handles much more information and provides more appropriate diagnostic and personalized treatments to individuals. In this paper, we present the objectives, structure and expected innovations of the TAMESIS project. TAMESIS aims to contribute in advancing the state of the art of some of the technologies needed for the development of Personal Health Systems. Specifically, we propose techniques for preventing denial of service, sensor node malfunctioning and traffic injection. In addition, we explore a protocol that makes use of mobile agents for the exchange of medical records between networked databases. As a novel aspect, the protocol will not only support bilateral agreements, already existing in the literature, but multilateral agreements. In reference to clinical data, is critical to preserve the privacy and intimacy of patients. Thus, the data, at the time of being collected as for when it is exchanged, should be processed so as to avoid leakage of information that is not strictly necessary for the parties to fulfill their task correctly. A privacy metric suitable for PHS, and the incorporation of mechanisms needed for privacy and intimacy are also key objectives of this project. Finally, usability aspects of all the system interfaces will be considered.

Research paper thumbnail of A new cross-layer attack to TCP in cognitive radio networks

2009 Second International Workshop on Cross Layer Design, 2009

... Failure in the retransmission of a lost segment due to persistence of the handoff, can even l... more ... Failure in the retransmission of a lost segment due to persistence of the handoff, can even lead to a worse situation in which the sender remains inactive for a long period of time, since the retransmission timer backs off (doubling its value) for each unsuccessful attempt. ...

Research paper thumbnail of Securing cognitive radio networks

International Journal of Communication Systems, 2010

Cognitive radio is a promising technology aiming to improve the utilization of the radio electrom... more Cognitive radio is a promising technology aiming to improve the utilization of the radio electromagnetic spectrum. A cognitive radio device uses general purpose computer processors that run radio applications software to perform signal processing. The use of this software enables the device to sense and understand its environment and actively change its mode of operation based on its observations. Unfortunately, this solution entails new security challenges. Our objective in this paper is to analyze the security issues of the main recent developments and architectures of cognitive radio networks. We present vulnerabilities inherent to those systems, identify novel types of abuse, classify attacks, and analyze their impact on the operation of cognitive radio‐based systems. Moreover, we discuss and propose security solutions to mitigate such threats. Copyright © 2010 John Wiley & Sons, Ltd.

Research paper thumbnail of The TAMESIS Project: Enabling Technologies for the Health Status Monitoring and Secure Exchange of Clinical Records

2013 Seventh International Conference on Complex, Intelligent, and Software Intensive Systems (Cisis), 2013

ABSTRACT Personal Health Systems (PHS) allow to move the point of care from hospitals to the pati... more ABSTRACT Personal Health Systems (PHS) allow to move the point of care from hospitals to the patient's home. Moreover, a PHS usually handles much more information and provides more appropriate diagnostic and personalized treatments to individuals. In this paper, we present the objectives, structure and expected innovations of the TAMESIS project. TAMESIS aims to contribute in advancing the state of the art of some of the technologies needed for the development of Personal Health Systems. Specifically, we propose techniques for preventing denial of service, sensor node malfunctioning and traffic injection. In addition, we explore a protocol that makes use of mobile agents for the exchange of medical records between networked databases. As a novel aspect, the protocol will not only support bilateral agreements, already existing in the literature, but multilateral agreements. In reference to clinical data, is critical to preserve the privacy and intimacy of patients. Thus, the data, at the time of being collected as for when it is exchanged, should be processed so as to avoid leakage of information that is not strictly necessary for the parties to fulfill their task correctly. A privacy metric suitable for PHS, and the incorporation of mechanisms needed for privacy and intimacy are also key objectives of this project. Finally, usability aspects of all the system interfaces will be considered.