AMOEBA: Robust Location Privacy Scheme for VANET

Communication messages in vehicular ad hoc networks (VANET) can be used to locate and track vehicles. While tracking can be beneficial for vehicle navigation, it can also lead to threats on location privacy of vehicle user. In this paper, we address the problem of mitigating unauthorized tracking of vehicles based on their broadcast communications, to enhance the user location privacy in VANET. Compared to other mobile networks, VANET exhibits unique characteristics in terms of vehicular mobility constraints, application requirements such as a safety message broadcast period, and vehicular network connectivity. Based on the observed characteristics, we propose a scheme called AMOEBA, that provides location privacy by utilizing the group navigation of vehicles. By simulating vehicular mobility in freeways and streets, the performance of the proposed scheme is evaluated under VANET application constraints and two passive adversary models. We make use of vehicular groups for anonymous access to location based service applications in VANET, for user privacy protection. The robustness of the user privacy provided is considered under various attacks.     

<Emphasis Type="Italic">EIAS-CP:</Emphasis> new efficient identity-based authentication scheme with conditional privacy-preserving for VANETs

In VANETs, vehicles broadcast traffic-related messages periodically according to Dedicated Short Range Communication protocol. To ensure the reliability and integrity of messages, authentication schemes are involved in VANETs. As traffic-related messages are time-sensitive, they must be verified and processed timely, or it may cause inestimable harm to the traffic system. However, the OBUs and the RSUs are limited in computation ability and cannot afford vast messages’ verification. Recently, some identity-based authentication schemes using bilinear pairing have been proposed to improve the efficiency of message verification for VANETs. Nevertheless, the bilinear pairing is not suited for VANETs due to its complex operations. The design of an efficient and secure authentication scheme with low computation cost for VANETs still is a rewarding challenge. To settle this challenge, a new efficient identity-based authentication scheme is proposed in this paper. The proposed scheme ensures reliability and integrity of messages and provides conditional privacy-preserving. Compared with the most recent proposed authentication schemes for VANETs, the computation costs of the message signing and verification in the proposed scheme reduce by 88 and 93 % respectively, while security analysis demonstrates that our proposed scheme satisfies all security and privacy requirements for VANETs.     

Wireless Location Privacy Protection in Vehicular Ad-Hoc Networks

Advances in mobile networks and positioning technologies have made location information a valuable asset in vehicular ad-hoc networks (VANETs). However, the availability of such information must be weighted against the potential for abuse. In this paper, we investigate the problem of alleviating unauthorized tracking of target vehicles by adversaries in VANETs. We propose a vehicle density-based location privacy (DLP) scheme which can provide location privacy by utilizing the neighboring vehicle density as a threshold to change the pseudonyms. We derive the delay distribution and the average total delay of a vehicle within a density zone. Given the delay information, an adversary may still be available to track the target vehicle by some selection rules. We investigate the effectiveness of DLP based on extensive simulation study. Simulation results show that the probability of successful location tracking of a target vehicle by an adversary is inversely proportional to both the traffic arrival rate and the variance of vehicles’ speed. Our proposed DLP scheme also has a better performance than both Mix-Zone scheme and AMOEBA with random silent period.     

A Street Broadcast Reduction Scheme (SBR) to Mitigate the Broadcast Storm Problem in VANETs

In urban vehicular wireless environments, several vehicles can send warning messages and so every vehicle within the transmission range will receive the broadcast transmission, possibly rebroadcasting these messages to other vehicles. This increases the number of vehicles receiving the traffic warning messages. Hence, redundancy, contention, and packet collisions due to simultaneous forwarding (usually known as the broadcast storm problem), can occur. In the past, several approaches have been proposed to solve the broadcast storm problem in wireless networks such as Mobile ad hoc Networks MANETs. In this paper, we present Street Broadcast Reduction SBR, a novel scheme that mitigates the broadcast storm problem in VANETs. SBR also reduces the warning message notification time and increases the number of vehicles that are informed about the alert.     

Fireworks: an intelligent location discovery algorithm for vehicular ad hoc networks

Searching for and locating a certain destination in a vehicular ad-hoc network (VANET) are fundamental issues to ensure routing and data dissemination under high mobility and lack of fixed infrastructure. However, naive-flooding searching is too expensive and takes a considerable amount of valuable bandwidth in the network. To overcome this, GPS information of the vehicles can be exploited, which can aid searching and routing in VANETs. In this paper, we present a novel position-based searching algorithm—called Fireworks—that can be used as a location discovery algorithm in VANETs. The proposed scheme is purely reactive and has a limited usage of beacons. Fireworks algorithm provides the position of the destination vehicle without having a Location Information System infrastructure or a proactive mechanism. We show that the method is efficient and reliable while greatly reducing the searching overhead. The simulations show that the algorithm covers as many nodes as naive-flooding with less than one-fifth of the broadcast messages and with less than one-third of the Dynamic Source Routing (DSR). It also performs better than Acknowledgement-Based Broadcast Protocol (ABSM) in terms of total number of broadcast messages, node coverage speed and query success rate.     

ReIDD: reliability-aware intelligent data dissemination protocol for broadcast storm problem in vehicular ad hoc networks

Vehicular ad hoc networks (VANETs) have emerged as fast growing networks with aims to provide safety, and comfort to the onboard passengers. But, in this environment reliable data dissemination to the destination nodes is one of the biggest challenges as there may be a congestion in the network due to blind flooding of messages to their final destination, called as broadcast storm which may lead to the performance degradation with respect to the metric such as-message delivery, reliability and response time. To address this issue, in this paper, we propose a reliability-aware intelligent data dissemination protocol for broadcast storm problem in VANETs. We have solved the above specified problem using game theory concepts in which players, strategy space and decisions with respect to the current state of the system. To reduce the message overhead with respect to the communication cost among the players of the game, in the proposed scheme, messages are routed to the next destination by selecting the most reliable path in an intelligent manner. A coalition game is formulated among the vehicles by considering vehicles as the players in the game. Each player in the game has an initial payoff value based upon the parameters such as-communication range, storage requirements, and computation power. Based upon the payoff value of the players in the game, different coalitions/clusters are formulated among the players in the proposed scheme. Then, the players send the messages to the other vehicles/players within the same coalition which increases the reliability of transmission. In the proposed scheme, messages are unicasted to their final destination in an intelligent manner. Different algorithms are designed for coalition formation, maintenance, and reliability-aware data dissemination. The performance of the proposed scheme is evaluated using various evaluation metrics such as-service time, packet delivery ration, and throughput. The results obtained prove the effectiveness of the proposed scheme as compared to the other state-of-the-art existing schemes.     

RPB-MD: Providing robust message dissemination for vehicular ad hoc networks

To improve traffic safety and efficiency, it is vital to reliably send traffic-related messages to vehicles in the targeted region in vehicular ad hoc networks (VANETs). In this paper, we propose a novel scheme, relative position based message dissemination (RPB-MD), to reliably and efficiently disseminate messages to the vehicles in the zone-of-relevance. Firstly, the relative position based (RPB) addressing model is proposed to effectively define the intended receivers in the zone-of-relevance. To ensure high message delivery ratio and low delivery delay, directional greedy broadcast routing (DGBR) is introduced to make a group of candidate nodes hold the message for high reliability. Moreover, to guarantee efficiency, the protocol time parameters are designed adaptively according to the message attributes and local vehicular traffic density. The protocol feasibility is analyzed to illustrate the robustness and reliability of RPB-MD. Simulation results show that RPB-MD, compared with representative existing schemes, achieves high delivery ratio, limited overhead, reasonable delay and high network reachability under different vehicular traffic density and data sending rate.     

Novel Advanced Broadcast Scheme for Efficient Safety Message Collision Alleviation in Vehicular Networks

Safety message broadcasting may cause a broadcast storm in vehicular ad-hoc network without an effective feedback mechanism. In particular, with increasing number of vehicles, serious collisions and incurred long delays are not acceptable for emergency safety messages. In this paper, we proposed an advanced broadcast scheme by the functionality of distributed coordination function and multi-channel operation in dedicated short range communication to decrease collision probability and increase received ratio of safety messages. The proposed scheme can increases safety message transmission efficiency and reduce the latency by delicately designing a rebroadcast probability, choosing the channel and selecting the backoff timer. After broadcasting in the control channel, transmitters return to their original service channel. Then, the vehicles receiving the safety message should inform the others in the same service channel to switch to the control channel for the safety message. Afterwards, the vehicles broadcast the safety message once and go back to the original service channel. This method can inform the other vehicles in different channels to increase the broadcast penetration. The proposed scheme can work without global positioning system (GPS). However, GPS can adapt the rebroadcast probability on hot spots to enhance the efficiency of the proposed scheme. Through detailed simulations, the proposed scheme is shown to be more efficient compared to the existing ones.     

A roadside unit‐based localization scheme for vehicular ad hoc networks

Vehicular Ad Hoc Networks (VANETs), designed to ensure the safety and comfort of passengers via the exchange of information amongst nearby vehicles or between the vehicles and Roadside Units (RSUs), have attracted particular attention. However, the success of many VANET applications depends on their ability to estimate the vehicle position with a high degree of precision, and thus, many vehicle localization schemes have been proposed. Many of these schemes are based on vehicle‐mounted Global Positioning System (GPS) receivers. However, the GPS signals are easily disturbed or obstructed. Although this problem can be resolved by vehicle‐to‐vehicle communication schemes, such schemes are effective only in VANETs with a high traffic density. Accordingly, this paper presents a VANET localization scheme in which each vehicle estimates its location on the basis of beacon messages broadcast periodically by pairs of RSUs deployed on either side of the road. In addition, three enhancements to the proposed scheme are presented for the RSU deployment, RSU beacon collisions, and RSU failures. Overall, the ns‐2 simulation results show that the localization scheme achieves a lower localization error than existing solutions on the basis of vehicle‐to‐vehicle communications and is robust toward changes in the traffic density and the vehicle speed. Copyright © 2012 John Wiley & Sons, Ltd.     

A Privacy-Preserving Location Assurance Protocol for Location-Aware Services in VANETs

A location-aware service on a vehicular ad hoc networks (VANETs) is to provide services that distribute on-demand information for a certain geographic area of interest by taking advantage of vehicular communications. In this paper, we propose a secure and location assurance protocol in order to guarantee privacy preservation in vehicular communications and trustworthiness of location-aware services over VANETs. The proposed protocol enables a message verifier to have confidence that the location-aware information was responded from the vehicles passing through the target location area of interest without violating location privacy of the responders. To achieve our security objectives, we consider a pseudonym-based privacy-preserving authentication and a hierarchical identity-based cryptographic scheme. Furthermore, we demonstrate experimental results to confirm the efficiency and effectiveness of the proposed protocol.     

SPECS: Secure and privacy enhancing communications schemes for VANETs

Vehicular ad hoc network (VANET) is an emerging type of networks which facilitates vehicles on roads to communicate for driving safety. The basic idea is to allow arbitrary vehicles to broadcast ad hoc messages (e.g. traffic accidents) to other vehicles. However, this raises the concern of security and privacy. Messages should be signed and verified before they are trusted while the real identity of vehicles should not be revealed, but traceable by authorized party. Existing solutions either rely heavily on a tamper-proof hardware device, or cannot satisfy the privacy requirement and do not have an effective message verification scheme. In this paper, we provide a software-based solution which makes use of only two shared secrets to satisfy the privacy requirement (with security analysis) and gives lower message overhead and at least 45% higher successful rate than previous solutions in the message verification phase using the bloom filter and the binary search techniques (through simulation study). We also provide the first group communication protocol to allow vehicles to authenticate and securely communicate with others in a group of known vehicles.     

MLAS: Multiple level authentication scheme for VANETs

The vehicular ad hoc network (VANET) is an emerging type of network which enables vehicles on roads to inter-communicate for driving safety. The basic idea is to allow arbitrary vehicles to broadcast ad hoc messages (e.g. traffic accidents) to other vehicles. However, this raises the concern of security and privacy. Messages should be signed and verified before they are trusted while the real identity of vehicles should not be revealed, but traceable by authorized party. Existing solutions either rely too heavily on a tamper-proof hardware device, or do not have an effective message verification scheme. In this paper, we propose a multiple level authentication scheme which still makes use of tamper-proof devices but the strong assumption that a long-term system master secret is preloaded into all tamper-proof devices is removed. Instead the master secret can be updated if needed to increase the security level. On the other hand, messages sent by vehicles are classified into two types – regular messages and urgent messages. Regular messages can be verified by neighboring vehicles by means of Hash-based Message Authentication Code (HMAC) while urgent messages can only be verified with the aid of RSUs nearby by means of a conditional privacy-preserving authentication scheme. Through extensive simulation, we show that our multiple level authentication scheme is much more efficient that those RSU-aided authentication scheme as long as the proportion of urgent messages is less than 100%. The verification delay required can be up to 110 times smaller than other protocols. Our implementation shows that batch verification may not be as efficient as expected. In case without batch verification, the verification delay required by our scheme can even be up to 173 times smaller.     

物联网环境中基于车联网与3G网络的跨层安全相关广播业务结构(英文)

As Vehicle Ad Hoc Networks (VANETs) is part of the applications of the Internet of Things (IoT), and Vehicles in VANETs periodically broadcast the beacon message for status advertisement to provide public safety, the impacts of the network parameters on the reliability of broadcast messages are investigated and discussed; meanwhile, a cross-layer safety-critical broadcast service architecture is proposed to obtain an optimized set of packet loss rate and delay based on the Neural Networks (NN) and Back Prop...     

Pseudonym changing strategy with multiple mix zones for trajectory privacy protection in road networks

In road network, vehicles' location may be identified, and their transmissions may even tracked by eavesdrops (eg, safety messages) that contain sensitive personal information such as identity and location of the vehicle. This type of communication leads to breaking the users' trajectory privacy. Frequently changing pseudonyms are widely accepted as a solution that protects the trajectory privacy of users in road networks. However, this solution may become invalid if a vehicle changes its pseudonym at an improper occasion. To cope with this issue, we presented an efficient pseudonym change strategy with multiple mix zones scheme to provide trajectory privacy for road network. In addition, we protected vehicles against linkability attack by cheating mechanism. Henceforth, we constructed a cheating detection mechanism which allows the vehicles to verify whether the pseudonym change process is successful or not and also detect to malicious vehicles. In this way, users' trajectory privacy can be improved. Finally, by taking the anonymity set size (ASS) as the trajectory privacy metric, we exhibit by means of simulations that the proposed scheme is effective in multiple networks scenarios.     

Optimal solution for malicious node detection and prevention using hybrid chaotic particle dragonfly swarm algorithm in VANETs

Vehicular ad hoc networks (VANETs) have the ability to make changes in travelling and driving mode of people and so on, in which vehicle can broadcast and forward the message related to emergency or present road condition. The safety and efficiency of modern transportation system is highly improved using VANETs. However, the vehicular communication performance is weakened with the sudden emergence of distributed denial of service (DDoS) attacks. Among other attacks, DDoS attack is the fastest attack degrading the VANETs performance due to its node mobility nature. Also, the attackers (cyber terrorists, politicians, etc.) have now considered the DDoS attack as a network service degradation weapon. In current trend, there is a quick need for mitigation and prevention of DDoS attacks in the exploration field. To resolve the conflict of privacy preservation, we propose a fast and secure HCPDS based framework for DDoS attack detection and prevention in VANETs. The Road Side Units (RSUs) have used HCPDS algorithm to evaluate the fitness values of all vehicles. This evaluation process is done for effective detection of spoofing and misbehaving nodes by comparing the obtained fitness value with the statistical information (packet factors, RSU zone, and vehicle dynamics) gathered from the vehicles. The credentials of all worst nodes are cancelled to avoid further communication with other vehicles. In HCPDS algorithm, the PSO updation strategy is added to Dragon fly algorithm to improve the search space. In addition, Chaos theory is applied to tune the parameters of proposed HCPDS algorithm. From the experimental results, it proved that the HCPDS based proposed approach can efficiently meet the requirements of security and privacy in VANETs.

     

Fast randomized algorithm for 2-hops clustering in vehicular ad-hoc networks

Vehicular Ad-Hoc Networks (VANETs) enable inter vehicle wireless communication as well as communication with road side equipment. Warning messages can be exchanged among nearby vehicles, helping to predict dangerous situations, and thus improving road safety. Such safety messages require fast delivery and minimal delay to local areas, in order for them to be effective. Therefore, a fast and efficient channel access scheme is required. A feasible solution, derived from the Mobile Ad-Hoc Networks (MANETs) field, groups nodes into smaller manageable sections called clusters. Such an approach can be beneficial for locally delivering messages under strict time constraints. In this paper, a Hierarchical Clustering Algorithm (HCA) is presented. HCA is a distributed randomized algorithm, which manages channel access by forming three hierarchy clusters. The proposed channel access scheme enables delay bounded reliable communication. Unlike other common clustering algorithm for VANETs, HCA does not require the knowledge of the vehicles’ locations. This feature guarantees accurate operation even when localization systems such as GPS are not available. The running time and message complexity were analyzed and simulated. Simulation results show that the algorithm behaves well especially under realistic mobility patterns; therefore, it is a suitable solution for channel access scheme for VANETs.     

一种基于可靠最远转发的车载网广播协议

许多车载自组网应用依赖于可靠高效的广播,但车载自组网节点高速移动,网络连通性随场景和时间动态变化的特性给广播协议的设计带来巨大挑战。为了应对这种挑战,该文在分析和验证简单最远转发机制具有低可靠性的同时,提出一种基于广播方向的可靠最远转发策略,并结合捎带确认机制设计了一种新的自组网多跳广播协议。与简单最远转发相比,可靠最远转发能明显降低转发节点失效的概率,提高消息单跳传播的可靠性;捎带确认机制使得协议能够适应网络连通性较差的场景,提升了消息全网传播的可靠性。仿真结果表明,提出的协议能在各种场景中实现高可靠性、低冗余的广播。     

QoS‐aware broadcasting in VANETs based on fuzzy logic and enhanced kinetic multipoint relay

Vehicular ad hoc networks (VANETs) are emergent concepts in terms of infrastructure‐less communication. The data dissemination is usually done using broadcast schemes. Data broadcast in VANETs is a challenging issue due to the high mobility vehicles and the varying density. On one hand, these vehicles have to share and disseminate the safety‐critical information, in real time, to other intended vehicles. On the other hand, the existing broadcast solutions do not succeed, till now, to fulfill VANETs requirements especially in terms of performance and QoS. In this paper, we propose a new QoS‐aware broadcast method in order to face VANETs communications challenges. We choose to adapt a concept originally devoted to mobile ad hoc networks (MANETs) and join it to other specific VANET techniques to introduce a new broadcasting protocol in the aim of optimizing QoS fulfilment. The proposed solution is fundamentally based on enhanced kinetic strategy assisted with fuzzy logic for QoS‐aware multipoint relay (MPR). The protocol efficiency is eventually tested through an experimental study and compared with existing methods. The results prove the over‐performance of the proposed solution.     

Information dissemination in VANETs based upon a tree topology

In this work, we focus on vehicular ad hoc networks, also called VANETs, which are communication networks that devices (in this case vehicles) use to exchange messages in a decentralized fashion, i.e., using no preexisting infrastructure. We first assess the feasibility of relying on a tree-based topology management structure for mobile ad hoc networks and in particular for VANETs. Next, we enhance DAGRS, an existing decentralized model for enabling distributed tree management and build BODYF on it, an efficient broadcast algorithm. Several broadcasting algorithms of the state of the art are implemented in order to compare the performance of BODYF. The approach is validated by simulation through three realistic scenarios located in Luxembourg city: the city center for both pedestrian and vehicles, and a highway environment. The comparison is made in terms of the coverage achieved by the broadcasting process as well as the complexity of the messages. DAGRS/BODYF approach outperforms other existing protocols in terms of both the number of devices reached and the network use.     

Cluster-based multi-channel communications protocols in vehicle ad hoc networks

The dedicated short range communications (DSRC) standard equipped with seven channels is designated for intelligent transportation system (ITS) applications to improve the driving safety and support networking services among moving vehicles. Making best use of the DSRC multichannel architecture, we propose a cluster-based multichannel communications scheme, which integrates the clustering with contention-free/contention-based MAC protocols. In our proposed scheme, the elected cluster-head (CH) vehicle functions as the coordinator (like WLAN's basestation) to collect/deliver the real-time safety messages within its own cluster and forward the consolidated safety messages to the neighboring CHs. Also, the CH vehicle controls channel-assignments for cluster-member vehicles transmitting/receiving the non-real-time traffics, which makes the wireless channels more efficiently utilized for the non-real-time data transmissions. Our scheme uses the contention-free MAC (TDMA/broadcast) within a cluster and the IEEE 802.11 MAC among CH vehicles such that the real-time delivery of safety messages can be guaranteed. The simulation results show that our proposed scheme can significantly improve the throughputs of vehicle data communications while guaranteeing the real-time delivery of safety messages