My current research interests are security and privacy in Cyber-Physical Systems, especially Intelligent Transportation Systems.
From 2011 to 2014, I coordinated the European FP7 PRESERVE project at the University of Twente. The goal of PRESERVE is to design, implement and test a V2X Security Subsystem for realistic deployment scenarios.
The main contribution of my PhD thesis is an analytical model that assesses the overhead of authentication mechanisms. Supervisors: Zoubir Mammeri and Frank Kargl
Safety-critical applications in cooperative vehicular networks require authentication of nodes an... more Safety-critical applications in cooperative vehicular networks require authentication of nodes and messages. Yet, privacy of individual vehicles and drivers must be maintained. Pseudonymity can satisfy both security and privacy requirements. Thus, a large body of work emerged in recent years, proposing pseudonym solutions tailored to vehicular networks. In this survey, we detail the challenges and requirements for such pseudonym mechanisms, propose an abstract pseudonym lifecycle, and give an extensive overview and categorization of the state of the art in this research area. Specifically, this survey covers pseudonym schemes based on public key and identity-based cryptography, group signatures and symmetric authentication. We compare the different approaches, give an overview of the current state of standardization, and identify open research challenges.
Vehicle automation has been one of the fundamental applications within the field of intelligent t... more Vehicle automation has been one of the fundamental applications within the field of intelligent transportation systems (ITS) since the start of ITS research in the mid-1980s. For most of this time, it has been generally viewed as a futuristic concept that is not close to being ready for deployment. However, recent development of “self-driving” cars and the announcement by car manufacturers of their deployment by 2020 show that this is becoming a reality. The ITS industry has already been focusing much of its attention on the concepts of “connected vehicles” (United States) or “cooperative ITS” (Europe). These concepts are based on communication of data among vehicles (V2V) and/or between vehicles and the infrastructure (V2I/I2V) to provide the information needed to implement ITS applications. The separate threads of automated vehicles and cooperative ITS have not yet been thoroughly woven together, but this will be a necessary step in the near future because the cooperative exchange of data will provide vital inputs to improve the performance and safety of the automation systems. Thus, it is important to start thinking about the cybersecurity implications of cooperative automated vehicle systems. In this paper, we investigate the potential cyberattacks specific to automated vehicles, with their special needs and vulnerabilities. We analyze the threats on autonomous automated vehicles and cooperative automated vehicles. This analysis shows the need for considerably more redundancy than many have been expecting. We also raise awareness to generate discussion about these threats at this early stage in the development of vehicle automation systems.
In-network aggregation mechanisms for vehicular ad hoc networks (VANETs) aim at improving communi... more In-network aggregation mechanisms for vehicular ad hoc networks (VANETs) aim at improving communication efficiency by summarizing information that is exchanged between vehicles. Summaries are calculated, while data items are generated in and forwarded through the network. Due to its high bandwidth saving potential, aggregation is a vital building block for many of the applications envisioned in VANETs. At the same time, the specific environment of VANETs calls for novel approaches to aggregation, which address their challenging requirements. In this paper, we survey and structure this active research field. We propose a generic model to describe and classify the proposed approaches, and we identify future research challenges.
User privacy is a requirement for wireless vehicular communications, and a number of privacy prot... more User privacy is a requirement for wireless vehicular communications, and a number of privacy protection strategies have already been developed and standardized. In particular, methods relying on the use of temporary pseudonyms and silent periods have proved their ability to confuse attackers who would attempt to track vehicles. In addition to their ability to protect privacy, it is important to ensure that these privacy strategies do not hinder the safety applications which rely on vehicular communications. This paper addresses this concern and presents an experimental analysis of the impact of privacy strategies on Intersection Collision Avoidance (ICA) systems. We simulate traffic scenarios at a road intersection and compare the ability of a collision avoidance system to avoid collisions for different pseudonym change schemes. The privacy level is analyzed, as well as the influence of the duration of the silent period on the safety performance of the ICA system. The results highlight the need to jointly design safety applications and privacy strategies.
Vehicular networking enables new safety applica- tions that aim at improving roads safety. Becaus... more Vehicular networking enables new safety applica- tions that aim at improving roads safety. Because of their direct relation to driver’s safety, this goal can only be achieved if vehicular networking is based on a technology that is robust against malicious attackers. Therefore, security mechanisms such as authentication are proposed. However, security comes at a cost in terms of computational and communication overhead. For example, a signature and certificate are appended to every beacon sent, which generates an extra load on the network. Moreover, most of the safety applications require a perfect awareness of the vehicle’s surroundings to perform adequately. To represent such awareness, the Awareness Quality is used to indicate the current level of awareness of the vehicle. This metric was previously used by the Decentralized Congestion Control community to improve channel usage. In this paper, we use the Awareness Quality to investigate the impact of security on cooperative awareness in VANET. Then, we apply this metric to the mechanism of certificate omission, and provide extensive simulation results. The attributes of Awareness Quality metrics enable us to investigate the behavior of certificate omission schemes with a precision that was not provided by aggregate metrics. This enables us to show that congestion-based certificate omission with a quadratic adaption function is the most effective scheme among existing certificate omission schemes.
Proceedings of the 2013 ACM workshop on Security, privacy & dependability for cyber vehicles, 2013
Current standardization efforts for cooperative Intelligent Transportation Systems both in the U.... more Current standardization efforts for cooperative Intelligent Transportation Systems both in the U.S. and Europe foresee vehicles to use a large number of changeable pseudonyms for privacy protection. Provisioning and storage of these pseudonyms require efficient and secure mechanisms to prevent malicious use of pseudonyms. In this paper we investigate several techniques to improve secure and efficient storage of pseudonyms. Specifically, we propose schemes based on Physical Unclonable Functions (PUFs) that allow to replace expensive secure key storage by regular unsecured memory and still provide fully secure pseudonyms storage.
Proceedings of the 2013 ACM workshop on Security, privacy & dependability for cyber vehicles, 2013
Upcoming years will see a massive deployment of electric vehicles and, combined with this, of cha... more Upcoming years will see a massive deployment of electric vehicles and, combined with this, of charging infrastructure. This will require protocols and standards that will control authentication, authorization, and billing of electric-vehicle charging. The ISO/IEC 15118 protocol that addresses the communication between the charging station and the vehicle is going to play an important role, at least in Europe. While it foresees security protection, there are no significant mechanisms for privacy protection in place. In this paper, we investigate the privacy protection of ISO/IEC 15118 and the surrounding charging and payment infrastructure by means of a Privacy Impact Assessment (PIA). Based on this we propose modular extensions of the protocol applying state-of-the-art Privacy Enhancing Technologies like anonymous credentials to come to a system with maximum privacy protection. We conducted a second PIA to show the benefits to privacy protection that our POPCORN protocol provides compared to the original ISO/IEC 15118. We also describe a proof-of-concept implementation of our system based on a model of electric vehicle and charging station that shows the feasibility of our approach and allows a first preliminary analysis of performance and other issues.
Wireless communication between vehicles is protected by digital certificates but these certificat... more Wireless communication between vehicles is protected by digital certificates but these certificates and related identifiers must not be usable to track vehicles. Therefore, short-term pseudonymous certificates are applied and regularly changed in order to protect the driver's privacy. But in well defined situations, e.g. network attacks or traffic accidents, it should be possible to retrieve the appropriate long-term identifier from the certificate issuer. Hence, the resolution of pseudonym identifiers is a balancing act between full privacy and uncontrolled access to long-term identifiers. We propose a generic pseudonym resolution protocol that can be applied by network infrastructure entities to request pseudonym resolution information only under defined conditions. It is shown that the protocol is balanced and flexible to be applied for different use cases (e.g. lawful interception or misbehavior detection). In contrast to related protocols our solution does not increase pseudonym certificate size and avoids additional overhead and delay in the certificate acquisition phase. Further, a new feature is proposed that enables the infrastructure entities to validate the stated reason for the desired pseudonym resolution before respective information is provided. Measurements from field operational test implementations show the feasibility and practicability of the protocol when applying misbehavior detection in wireless vehicular communication networks.
Most proposals for security of vehicular networks foresee the generation of a comparatively large... more Most proposals for security of vehicular networks foresee the generation of a comparatively large number of changing pseudonyms to prevent vehicles from being identified or tracked. Most proposals rely on communication with backend pseudonym providers to refill a vehicle’s pseudonym pool which creates a number of problems, one being secure storage and handling of a large amount of private key material. In this paper we investigate the usage of Physical Unclonable Functions (PUFs) and Public PUFs (PPUFs) instead of Hardware Security Modules for this purpose. While posing some challenges, PUFs and PPUFs provide a cheaper solution that also offer benefits for Sybil attack prevention. We describe a possible solution that uses Fuzzy Extractors to provide the necessary stability.
Proceedings of the ninth ACM international …, 2012
Telematic awareness of nearby vehicles is a basic foundation of electronic safety applications in... more Telematic awareness of nearby vehicles is a basic foundation of electronic safety applications in Vehicular Ad hoc Networks (VANETs). This awareness is achieved by frequently broadcasting beacon messages to nearby vehicles that announce a vehicle's location and other data like heading and speed. Such safety-related beacons require strong integrity protection and high availability, two properties that are hard to combine
Trustworthy communication in vehicular ad-hoc networks is essential to provide functional and rel... more Trustworthy communication in vehicular ad-hoc networks is essential to provide functional and reliable traffic safety and efficiency applications. A Sybil attacker that is simulating "ghost vehicles" on the road, by sending messages with faked position statements, must be detected and excluded permanently from the network. Based on misbehavior detection systems, running on vehicles and roadside units, a central evaluation scheme
Vehicular ad hoc networks aim at enhancing road safety by providing vehicle-to-vehicle communicat... more Vehicular ad hoc networks aim at enhancing road safety by providing vehicle-to-vehicle communications and safety- related applications. But safety-related applications, like Local Danger Warning, need a high trust level in received messages. Indeed, decisions are made depending on these messages. To increase the trustworthiness, a consensus mechanism is used. Thus, vehicles make a decision when a threshold is reached. Setting this threshold is of main importance because it impacts the decision delay, and thus, the remaining time for a driver reaction. In this paper, we investigate the problem of threshold establishment without globally unique identifier system (GUID). We propose to model the threshold as a Kalman filter and provide an algorithm to dynamically update the threshold. By simulations, we investigate the problem of insider attackers that generate information forgery attacks. Simulation results show that our dynamic method suffers from a bootstrapping phase but reduces the percentage of wrong decisions. Nevertheless, as future work, further analysis of default threshold value will be done.
Abstract Vehicular networks are one of the most challenging research areas in wireless ad hoc ne... more Abstract Vehicular networks are one of the most challenging research areas in wireless ad hoc networks. The main benefit of this kind of communication is seen in active safety systems, which aim at increasing passengers' safety by exchanging warning messages ...
ehicular ad hoc networks provide vehicle-to-vehicle communications and safety-related application... more ehicular ad hoc networks provide vehicle-to-vehicle communications and safety-related applications to enhance the road safety. However, safety-related applications, like Local Danger Warning, need a high trust level in received messages. Indeed, decisions are made depending on these messages. To increase the trustworthiness, a consensus mechanism is used. With consensus, vehicles need to receive at least X times the same warning before making a decision. Because the consensus should meet real-time constraints of safety applications, a main issue is to set parameter X. In this paper, we investigate the problem of consensus and propose a generic model to define decision method involved in consensus. Then, we propose to dynamically set the consensus parameter according to the neighborhood density and the warning criticalness. The proposed mechanism enhances the “majority of freshest X with threshold” decision method [1] and is analytically modeled. This context-aware and data-centric security mechanism ensures a quick and correct decision. We present some simulation results that validate our model.
Safety and non-safety applications envisioned for Vehicular Ad hoc NETworks (VANETs) heavily rely... more Safety and non-safety applications envisioned for Vehicular Ad hoc NETworks (VANETs) heavily rely on broad- casting for the exchange of data and status messages. New threats to road safety and efficiency raise if security requirements for broadcasting are not properly met. The decision whether or not a driver can trust information about a reported hazard should take into account the tradeoff between the decision delay, false warning probability and likelihood of missing the hazard. Although broadcasting in VANETs has been analytically studied at least for the simplified assumptions, related works do not jointly consider the reliability of the medium access control (MAC) protocol and the trust issues. In this letter, a new analytical model is designed for evaluating the latency required to guarantee trustworthiness in VANETs. This model explicitly accounts the operation of 802.11p/WAVE MAC protocol and computes mean decision delay as a function of number of vehicles, ratio of intruders as well as contention window sizes.
Vehicular ad hoc networks aim at increasing passenger safety by exchanging warning messages be- t... more Vehicular ad hoc networks aim at increasing passenger safety by exchanging warning messages be- tween vehicles wirelessly. A main challenge is to resist to various malicious abuses and security attacks. How- ever, any security mechanism comes with overhead. We analyze how the authentication algorithm ECDSA and the consensus mechanism impact the vehicular network performance and the braking distance. Processing and communication overheads, decision methods for consen- sus, are analyzed by analytical models and intensive simulations. We propose a formula to assess the total time overhead of the authentication. Results conclude that the authentication key size should be chosen care- fully, and the decision method should be adapted to the context.
Safety-critical applications in cooperative vehicular networks require authentication of nodes an... more Safety-critical applications in cooperative vehicular networks require authentication of nodes and messages. Yet, privacy of individual vehicles and drivers must be maintained. Pseudonymity can satisfy both security and privacy requirements. Thus, a large body of work emerged in recent years, proposing pseudonym solutions tailored to vehicular networks. In this survey, we detail the challenges and requirements for such pseudonym mechanisms, propose an abstract pseudonym lifecycle, and give an extensive overview and categorization of the state of the art in this research area. Specifically, this survey covers pseudonym schemes based on public key and identity-based cryptography, group signatures and symmetric authentication. We compare the different approaches, give an overview of the current state of standardization, and identify open research challenges.
Vehicle automation has been one of the fundamental applications within the field of intelligent t... more Vehicle automation has been one of the fundamental applications within the field of intelligent transportation systems (ITS) since the start of ITS research in the mid-1980s. For most of this time, it has been generally viewed as a futuristic concept that is not close to being ready for deployment. However, recent development of “self-driving” cars and the announcement by car manufacturers of their deployment by 2020 show that this is becoming a reality. The ITS industry has already been focusing much of its attention on the concepts of “connected vehicles” (United States) or “cooperative ITS” (Europe). These concepts are based on communication of data among vehicles (V2V) and/or between vehicles and the infrastructure (V2I/I2V) to provide the information needed to implement ITS applications. The separate threads of automated vehicles and cooperative ITS have not yet been thoroughly woven together, but this will be a necessary step in the near future because the cooperative exchange of data will provide vital inputs to improve the performance and safety of the automation systems. Thus, it is important to start thinking about the cybersecurity implications of cooperative automated vehicle systems. In this paper, we investigate the potential cyberattacks specific to automated vehicles, with their special needs and vulnerabilities. We analyze the threats on autonomous automated vehicles and cooperative automated vehicles. This analysis shows the need for considerably more redundancy than many have been expecting. We also raise awareness to generate discussion about these threats at this early stage in the development of vehicle automation systems.
In-network aggregation mechanisms for vehicular ad hoc networks (VANETs) aim at improving communi... more In-network aggregation mechanisms for vehicular ad hoc networks (VANETs) aim at improving communication efficiency by summarizing information that is exchanged between vehicles. Summaries are calculated, while data items are generated in and forwarded through the network. Due to its high bandwidth saving potential, aggregation is a vital building block for many of the applications envisioned in VANETs. At the same time, the specific environment of VANETs calls for novel approaches to aggregation, which address their challenging requirements. In this paper, we survey and structure this active research field. We propose a generic model to describe and classify the proposed approaches, and we identify future research challenges.
User privacy is a requirement for wireless vehicular communications, and a number of privacy prot... more User privacy is a requirement for wireless vehicular communications, and a number of privacy protection strategies have already been developed and standardized. In particular, methods relying on the use of temporary pseudonyms and silent periods have proved their ability to confuse attackers who would attempt to track vehicles. In addition to their ability to protect privacy, it is important to ensure that these privacy strategies do not hinder the safety applications which rely on vehicular communications. This paper addresses this concern and presents an experimental analysis of the impact of privacy strategies on Intersection Collision Avoidance (ICA) systems. We simulate traffic scenarios at a road intersection and compare the ability of a collision avoidance system to avoid collisions for different pseudonym change schemes. The privacy level is analyzed, as well as the influence of the duration of the silent period on the safety performance of the ICA system. The results highlight the need to jointly design safety applications and privacy strategies.
Vehicular networking enables new safety applica- tions that aim at improving roads safety. Becaus... more Vehicular networking enables new safety applica- tions that aim at improving roads safety. Because of their direct relation to driver’s safety, this goal can only be achieved if vehicular networking is based on a technology that is robust against malicious attackers. Therefore, security mechanisms such as authentication are proposed. However, security comes at a cost in terms of computational and communication overhead. For example, a signature and certificate are appended to every beacon sent, which generates an extra load on the network. Moreover, most of the safety applications require a perfect awareness of the vehicle’s surroundings to perform adequately. To represent such awareness, the Awareness Quality is used to indicate the current level of awareness of the vehicle. This metric was previously used by the Decentralized Congestion Control community to improve channel usage. In this paper, we use the Awareness Quality to investigate the impact of security on cooperative awareness in VANET. Then, we apply this metric to the mechanism of certificate omission, and provide extensive simulation results. The attributes of Awareness Quality metrics enable us to investigate the behavior of certificate omission schemes with a precision that was not provided by aggregate metrics. This enables us to show that congestion-based certificate omission with a quadratic adaption function is the most effective scheme among existing certificate omission schemes.
Proceedings of the 2013 ACM workshop on Security, privacy & dependability for cyber vehicles, 2013
Current standardization efforts for cooperative Intelligent Transportation Systems both in the U.... more Current standardization efforts for cooperative Intelligent Transportation Systems both in the U.S. and Europe foresee vehicles to use a large number of changeable pseudonyms for privacy protection. Provisioning and storage of these pseudonyms require efficient and secure mechanisms to prevent malicious use of pseudonyms. In this paper we investigate several techniques to improve secure and efficient storage of pseudonyms. Specifically, we propose schemes based on Physical Unclonable Functions (PUFs) that allow to replace expensive secure key storage by regular unsecured memory and still provide fully secure pseudonyms storage.
Proceedings of the 2013 ACM workshop on Security, privacy & dependability for cyber vehicles, 2013
Upcoming years will see a massive deployment of electric vehicles and, combined with this, of cha... more Upcoming years will see a massive deployment of electric vehicles and, combined with this, of charging infrastructure. This will require protocols and standards that will control authentication, authorization, and billing of electric-vehicle charging. The ISO/IEC 15118 protocol that addresses the communication between the charging station and the vehicle is going to play an important role, at least in Europe. While it foresees security protection, there are no significant mechanisms for privacy protection in place. In this paper, we investigate the privacy protection of ISO/IEC 15118 and the surrounding charging and payment infrastructure by means of a Privacy Impact Assessment (PIA). Based on this we propose modular extensions of the protocol applying state-of-the-art Privacy Enhancing Technologies like anonymous credentials to come to a system with maximum privacy protection. We conducted a second PIA to show the benefits to privacy protection that our POPCORN protocol provides compared to the original ISO/IEC 15118. We also describe a proof-of-concept implementation of our system based on a model of electric vehicle and charging station that shows the feasibility of our approach and allows a first preliminary analysis of performance and other issues.
Wireless communication between vehicles is protected by digital certificates but these certificat... more Wireless communication between vehicles is protected by digital certificates but these certificates and related identifiers must not be usable to track vehicles. Therefore, short-term pseudonymous certificates are applied and regularly changed in order to protect the driver's privacy. But in well defined situations, e.g. network attacks or traffic accidents, it should be possible to retrieve the appropriate long-term identifier from the certificate issuer. Hence, the resolution of pseudonym identifiers is a balancing act between full privacy and uncontrolled access to long-term identifiers. We propose a generic pseudonym resolution protocol that can be applied by network infrastructure entities to request pseudonym resolution information only under defined conditions. It is shown that the protocol is balanced and flexible to be applied for different use cases (e.g. lawful interception or misbehavior detection). In contrast to related protocols our solution does not increase pseudonym certificate size and avoids additional overhead and delay in the certificate acquisition phase. Further, a new feature is proposed that enables the infrastructure entities to validate the stated reason for the desired pseudonym resolution before respective information is provided. Measurements from field operational test implementations show the feasibility and practicability of the protocol when applying misbehavior detection in wireless vehicular communication networks.
Most proposals for security of vehicular networks foresee the generation of a comparatively large... more Most proposals for security of vehicular networks foresee the generation of a comparatively large number of changing pseudonyms to prevent vehicles from being identified or tracked. Most proposals rely on communication with backend pseudonym providers to refill a vehicle’s pseudonym pool which creates a number of problems, one being secure storage and handling of a large amount of private key material. In this paper we investigate the usage of Physical Unclonable Functions (PUFs) and Public PUFs (PPUFs) instead of Hardware Security Modules for this purpose. While posing some challenges, PUFs and PPUFs provide a cheaper solution that also offer benefits for Sybil attack prevention. We describe a possible solution that uses Fuzzy Extractors to provide the necessary stability.
Proceedings of the ninth ACM international …, 2012
Telematic awareness of nearby vehicles is a basic foundation of electronic safety applications in... more Telematic awareness of nearby vehicles is a basic foundation of electronic safety applications in Vehicular Ad hoc Networks (VANETs). This awareness is achieved by frequently broadcasting beacon messages to nearby vehicles that announce a vehicle's location and other data like heading and speed. Such safety-related beacons require strong integrity protection and high availability, two properties that are hard to combine
Trustworthy communication in vehicular ad-hoc networks is essential to provide functional and rel... more Trustworthy communication in vehicular ad-hoc networks is essential to provide functional and reliable traffic safety and efficiency applications. A Sybil attacker that is simulating "ghost vehicles" on the road, by sending messages with faked position statements, must be detected and excluded permanently from the network. Based on misbehavior detection systems, running on vehicles and roadside units, a central evaluation scheme
Vehicular ad hoc networks aim at enhancing road safety by providing vehicle-to-vehicle communicat... more Vehicular ad hoc networks aim at enhancing road safety by providing vehicle-to-vehicle communications and safety- related applications. But safety-related applications, like Local Danger Warning, need a high trust level in received messages. Indeed, decisions are made depending on these messages. To increase the trustworthiness, a consensus mechanism is used. Thus, vehicles make a decision when a threshold is reached. Setting this threshold is of main importance because it impacts the decision delay, and thus, the remaining time for a driver reaction. In this paper, we investigate the problem of threshold establishment without globally unique identifier system (GUID). We propose to model the threshold as a Kalman filter and provide an algorithm to dynamically update the threshold. By simulations, we investigate the problem of insider attackers that generate information forgery attacks. Simulation results show that our dynamic method suffers from a bootstrapping phase but reduces the percentage of wrong decisions. Nevertheless, as future work, further analysis of default threshold value will be done.
Abstract Vehicular networks are one of the most challenging research areas in wireless ad hoc ne... more Abstract Vehicular networks are one of the most challenging research areas in wireless ad hoc networks. The main benefit of this kind of communication is seen in active safety systems, which aim at increasing passengers' safety by exchanging warning messages ...
ehicular ad hoc networks provide vehicle-to-vehicle communications and safety-related application... more ehicular ad hoc networks provide vehicle-to-vehicle communications and safety-related applications to enhance the road safety. However, safety-related applications, like Local Danger Warning, need a high trust level in received messages. Indeed, decisions are made depending on these messages. To increase the trustworthiness, a consensus mechanism is used. With consensus, vehicles need to receive at least X times the same warning before making a decision. Because the consensus should meet real-time constraints of safety applications, a main issue is to set parameter X. In this paper, we investigate the problem of consensus and propose a generic model to define decision method involved in consensus. Then, we propose to dynamically set the consensus parameter according to the neighborhood density and the warning criticalness. The proposed mechanism enhances the “majority of freshest X with threshold” decision method [1] and is analytically modeled. This context-aware and data-centric security mechanism ensures a quick and correct decision. We present some simulation results that validate our model.
Safety and non-safety applications envisioned for Vehicular Ad hoc NETworks (VANETs) heavily rely... more Safety and non-safety applications envisioned for Vehicular Ad hoc NETworks (VANETs) heavily rely on broad- casting for the exchange of data and status messages. New threats to road safety and efficiency raise if security requirements for broadcasting are not properly met. The decision whether or not a driver can trust information about a reported hazard should take into account the tradeoff between the decision delay, false warning probability and likelihood of missing the hazard. Although broadcasting in VANETs has been analytically studied at least for the simplified assumptions, related works do not jointly consider the reliability of the medium access control (MAC) protocol and the trust issues. In this letter, a new analytical model is designed for evaluating the latency required to guarantee trustworthiness in VANETs. This model explicitly accounts the operation of 802.11p/WAVE MAC protocol and computes mean decision delay as a function of number of vehicles, ratio of intruders as well as contention window sizes.
Vehicular ad hoc networks aim at increasing passenger safety by exchanging warning messages be- t... more Vehicular ad hoc networks aim at increasing passenger safety by exchanging warning messages be- tween vehicles wirelessly. A main challenge is to resist to various malicious abuses and security attacks. How- ever, any security mechanism comes with overhead. We analyze how the authentication algorithm ECDSA and the consensus mechanism impact the vehicular network performance and the braking distance. Processing and communication overheads, decision methods for consen- sus, are analyzed by analytical models and intensive simulations. We propose a formula to assess the total time overhead of the authentication. Results conclude that the authentication key size should be chosen care- fully, and the decision method should be adapted to the context.
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Papers by Jonathan Petit
In this letter, a new analytical model is designed for evaluating the latency required to guarantee trustworthiness in VANETs. This model explicitly accounts the operation of 802.11p/WAVE MAC protocol and computes mean decision delay as a function of number of vehicles, ratio of intruders as well as contention window sizes.
In this letter, a new analytical model is designed for evaluating the latency required to guarantee trustworthiness in VANETs. This model explicitly accounts the operation of 802.11p/WAVE MAC protocol and computes mean decision delay as a function of number of vehicles, ratio of intruders as well as contention window sizes.