2,235 research outputs found
Security and Privacy Issues in Wireless Mesh Networks: A Survey
This book chapter identifies various security threats in wireless mesh
network (WMN). Keeping in mind the critical requirement of security and user
privacy in WMNs, this chapter provides a comprehensive overview of various
possible attacks on different layers of the communication protocol stack for
WMNs and their corresponding defense mechanisms. First, it identifies the
security vulnerabilities in the physical, link, network, transport, application
layers. Furthermore, various possible attacks on the key management protocols,
user authentication and access control protocols, and user privacy preservation
protocols are presented. After enumerating various possible attacks, the
chapter provides a detailed discussion on various existing security mechanisms
and protocols to defend against and wherever possible prevent the possible
attacks. Comparative analyses are also presented on the security schemes with
regards to the cryptographic schemes used, key management strategies deployed,
use of any trusted third party, computation and communication overhead involved
etc. The chapter then presents a brief discussion on various trust management
approaches for WMNs since trust and reputation-based schemes are increasingly
becoming popular for enforcing security in wireless networks. A number of open
problems in security and privacy issues for WMNs are subsequently discussed
before the chapter is finally concluded.Comment: 62 pages, 12 figures, 6 tables. This chapter is an extension of the
author's previous submission in arXiv submission: arXiv:1102.1226. There are
some text overlaps with the previous submissio
When Distributed Consensus Meets Wireless Connected Autonomous Systems: A Review and A DAG-based Approach
The connected and autonomous systems (CAS) and auto-driving era is coming
into our life. To support CAS applications such as AI-driven decision-making
and blockchain-based smart data management platform, data and message
exchange/dissemination is a fundamental element. The distributed message
broadcast and forward protocols in CAS, such as vehicular ad hoc networks
(VANET), can suffer from significant message loss and uncertain transmission
delay, and faulty nodes might disseminate fake messages to confuse the network.
Therefore, the consensus mechanism is essential in CAS with distributed
structure to guaranteed correct nodes agree on the same parameter and reach
consistency. However, due to the wireless nature of CAS, traditional consensus
cannot be directly deployed. This article reviews several existing consensus
mechanisms, including average/maximum/minimum estimation consensus mechanisms
that apply on quantity, Byzantine fault tolerance consensus for request, state
machine replication (SMR) and blockchain, as well as their implementations in
CAS. To deploy wireless-adapted consensus, we propose a Directed Acyclic Graph
(DAG)-based message structure to build a non-equivocation data dissemination
protocol for CAS, which has resilience against message loss and unpredictable
forwarding latency. Finally, we enhance this protocol by developing a
two-dimension DAG-based strategy to achieve partial order for blockchain and
total order for the distributed service model SMR
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