Blockchain is a promising technology for establishing trust in IoT networks, where network nodes do not necessarily trust each other. Cryptographic hash links and distributed consensus mechanisms ensure that the data stored on an immutable blockchain can not be altered or deleted. However, blockchain mechanisms do not guarantee the trustworthiness of data at the origin. We propose a layered architecture for improving the end-to-end trust that can be applied to a diverse range of blockchain-based IoT applications. Our architecture evaluates the trustworthiness of sensor observations at the data layer and adapts block verification at the blockchain layer through the proposed data trust and gateway reputation modules. We present the performance evaluation of the data trust module using a simulated indoor target localization and the gateway reputation module using an end-to-end blockchain implementation, together with a qualitative security analysis for the architecture.
@cite_14 , the authors introduced the Delegated Proof-of-Stake consensus scheme for secure data sharing in blockchain-enabled Internet of Vehicles. They used reputation-based voting to select the miners, where the reputation of the miner candidates are calculated utilizing a multi-weight subjective logic scheme. They also proposed a contract theory based mechanism to incentivize the standby miners to participate in block verification. @cite_7 , a Lightweight Scalable Blockchain (LSB) for IoT was proposed with an IoT friendly consensus algorithm that incorporates a distributed trust method to the block verification mechanism. The proposed architecture has two tiers: overlay, and smart home networks. Based on direct and indirect evidence, the overlay network nodes build trust, which is used to reduce the number of transactions to be validated in a new block.
@cite_14 @cite_7
2890103652 2771747728 2952115223 2954103930
In the Internet of Vehicles (IoV), data sharing among vehicles is critical for improving driving safety and enhancing vehicular services. To ensure security and traceability of data sharing, existing studies utilize efficient delegated proof-of-stake consensus scheme as hard security solutions to establish blockchain-enabled IoV (BIoV). However, as the miners are selected from miner candidates by stake-based voting, defending against voting collusion between the candidates and compromised high-stake vehicles becomes challenging. To address the challenge, in this paper, we propose a two-stage soft security enhancement solution: 1) miner selection and 2) block verification. In the first stage, we design a reputation-based voting scheme to ensure secure miner selection. This scheme evaluates candidates’ reputation using both past interactions and recommended opinions from other vehicles. The candidates with high reputation are selected to be active miners and standby miners. In the second stage, to prevent internal collusion among active miners, a newly generated block is further verified and audited by standby miners. To incentivize the participation of the standby miners in block verification, we adopt the contract theory to model the interactions between active miners and standby miners, where block verification security and delay are taken into consideration. Numerical results based on a real-world dataset confirm the security and efficiency of our schemes for data sharing in BIoV. BlockChain (BC) has attracted tremendous attention due to its immutable nature and the associated security and privacy benefits. BC has the potential to overcome security and privacy challenges of Internet of Things (IoT). However, BC is computationally expensive, has limited scalability and incurs significant bandwidth overheads and delays which are not suited to the IoT context. We propose a tiered Lightweight Scalable BC (LSB) that is optimized for IoT requirements. We explore LSB in a smart home setting as a representative example for broader IoT applications. Low resource devices in a smart home benefit from a centralized manager that establishes shared keys for communication and processes all incoming and outgoing requests. LSB achieves decentralization by forming an overlay network where high resource devices jointly manage a public BC that ensures end-to-end privacy and security. The overlay is organized as distinct clusters to reduce overheads and the cluster heads are responsible for managing the public BC. LSB incorporates several optimizations which include algorithms for lightweight consensus, distributed trust and throughput management. Qualitative arguments demonstrate that LSB is resilient to several security attacks. Extensive simulations show that LSB decreases packet overhead and delay and increases BC scalability compared to relevant baselines. Abstract Cryptographic assets such as Bitcoin and Ethereum provide distributed consensus with a Proof-of-Work protocol and incentive-based engineering. The consensus is inherently dependent on the value of the asset due to the incentives. The value of these assets frequently fluctuates, which in turn influences the incentive component of the consensus mechanism. For a proof-of-work consensus to be secure, the participation reward must have a perceived real-world value. The future of this perception is not at all clear. The recent 70 drop in the value of Bitcoin versus the US Dollar may be precipitating a circle of declining security of the platform which we explore in depth in this paper. In this paper, we analyze the impact of fluctuations on the security of Bitcoin now, and in the future. We introduce a novel method to examine the rationale of a miner based on the price fluctuations. We integrate our method with an existing security evaluation framework and simulator. Using our approach, we determine and report on the impact of the value of the cryptographic asset on the security of the blockchain given the miner’s rationale. Our method allows us to evaluate the impact of different methods of incentive manipulation such as reduced block-reward and transaction fees, by simulation. The rapid development of blockchain technology and their numerous emerging applications has received huge attention in recent years. The distributed consensus mechanism is the backbone of a blockchain network. It plays a key role in ensuring the network's security, integrity, and performance. Most current blockchain networks have been deploying the proof-of-work consensus mechanisms, in which the consensus is reached through intensive mining processes. However, this mechanism has several limitations, e.g., energy inefficiency, delay, and vulnerable to security threats. To overcome these problems, a new consensus mechanism has been developed recently, namely proof of stake, which enables to achieve the consensus via proving the stake ownership. This mechanism is expected to become a cutting-edge technology for future blockchain networks. This paper is dedicated to investigating proof-of-stake mechanisms, from fundamental knowledge to advanced proof-of-stake-based protocols along with performance analysis, e.g., energy consumption, delay, and security, as well as their promising applications, particularly in the field of Internet of Vehicles. The formation of stake pools and their effects on the network stake distribution are also analyzed and simulated. The results show that the ratio between the block reward and the total network stake has a significant impact on the decentralization of the network. Technical challenges and potential solutions are also discussed.