Abstract-As modern vehicle and communication technologies advanced apace, people begin to believe that Intelligent Transportation System (ITS) would be achievable in one decade. ITS introduces information technology to the transportation infrastructures and aims to improve road safety and traffic efficiency. However, security is still a main concern in Vehicular Communication Systems (VCS). This can be addressed through secured group broadcast. Therefore, secure key management schemes are considered as a critical technique for network security. In this paper, we propose a framework for providing secure key management within the heterogeneous network. The security managers (SMs) play a key role in the framework by capturing the vehicle departure information, encapsulating block to transport keys and then executing rekeying to vehicles within the same security domain. The first part of this framework is a novel network topology based on a decentralised blockchain structure. The blockchain concept is proposed to simplify the distributed key management in heterogeneous VCS domains. The second part of the framework uses the dynamic transaction collection period to further reduce the key transfer time during vehicles handover. Extensive simulations and analysis show the effectiveness and efficiency of the proposed framework, in which the blockchain structure performs better in term of key transfer time than the structure with a central manager, while the dynamic scheme allows SMs to flexibly fit various traffic levels.

Abstract-Location-based Services (LBS) have gained popularity as a result of the advances in mobile and communication technologies. LBS provide users with relevant information based on their location. In spite of the desirable features provided by LBS, the geographic locations of users are not adequately protected. Location privacy is one of the major challenges in vehicular and mobile networks. In this article, we analyse the security and privacy requirements for LBS in vehicular and mobile networks. Specifically, this paper covers privacy enhancing technologies and cryptographic approaches that provide location privacy in vehicular and mobile networks. The different approaches proposed in literature are compared and open research areas are identified.

No abstract

Abstract-Delay Tolerant Network (DTN) comprises of nodes with small and limited resources including power and memory capacity. We propose the use of DTN as an alternate means of communication for the dissemination of emergency information in a post-disaster evacuation operation. We investigate the performance of DTN in providing emergency communication support services under packet dropping attacks. We consider internally motivated attacks where the nodes that are part of the emergency rescue team are compromised with malicious behaviours thereby dropping packets to disrupt the message dissemination during the evacuation operation. A way to mitigating malicious behaviour and improve network performance of DTN is to use incentives in exchanging information between nodes. Unlike existing schemes, we consider the Basic Watchdog Detection System which detects and acts against misbehaving nodes to reduce their overall impact on the network performance. We design a Collaborative Trust Management Scheme (CTMS) which is based on the Bayesian detection watchdog approach to detect selfish and malicious behaviour in DTN nodes. We have evaluated our proposed CTMS through extensive simulations and compared our results with the other existing schemes. Our evaluations show that the use of adequate collaborative strategies between well behaved nodes could improve the performance of Watchdog schemes taking into account the delivery ratio, routing cost and the message delay from the source node to the destination node.

Abstract-Vehicular Delay Tolerant Networking (VDTN) is a special instance of Vehicular Ad hoc Networking (VANET) and in particular Delay Tolerant Networking (DTN) that utilizes infrastructure to enhance connectivity in challenged environments. While VANETs assume end-to-end connectivity, DTNs and VDTNs do not. Such networks are characterized by dynamic topology, partitioning due to lack of end-to-end connectivity, and opportunistic encounters between nodes. Notably, VDTNs enhances the capabilities DTNs to provide support for delay and intermittent connectivity. Hence, they can easily find applicability in the early stages of the deployment of vehicular networks characterized by low infrastructure deployment as is obtainable in rural areas and in military communications. Privacy implementation and evaluation is a major challenge in VDTNs. Group communication has become one of the well discussed means for achieving effective privacy and packet routing in ad hoc networks including VDTNs. However, most existing privacy schemes lack flexibility in terms of the dynamics of group formation and the level of privacy achievable. Again, it is difficult to evaluate privacy for sparse VDTNs for rural area and early stages of deployment. This paper reports on an improved privacy scheme based on group communication scheme in VDTNs. We analyze the performance of our model in terms of trade-off between privacy and performance based on delivery overhead and message delivery ratio using simulations. While this is a work in progress, we report that our scheme offers considerable improvement against other group communication based schemes described in literature.