1 Introduction
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A brief background introduction about the IoVs and blockchain is presented.
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The ways of implementing the blockchain in the IoVs are compared from several aspects, such as security and privacy.
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The future research directions in the field of blockchain-enabled IoVs are pointed.
2 Background
2.1 Internet of Vehicles
2.2 Blockchain
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Hash of the previous block.
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Timestamp, difficulty of mining, random number (Nonce).
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Merkle root.
Consensus algorithms | Applications |
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PoW | Bitcoin, Litecoin, Ethereum |
PoS | PeerCoin, NXT, Ethereum |
DPoS | BitShare |
PBFT | Hyperledger Fabric |
Ripple | Ripple |
Tendermint | Tendermint |
Paxos | Google Chubby, ZooKeeper |
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Public blockchain Everyone can read and access the chain. In addition, everyone can send transactions and participate in the consensus process.
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Private blockchain Nodes will be limited and not every node can participate in the blockchain. The chain has strict management on access control.
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Consortium blockchain Some nodes that have authority in advance can be chosen to participate in the chain. Consortium blockchains can be seen as “partially decentralized.”
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Decentralization In a blockchain-based decentralized system, the rights and obligations of all nodes are equal. The operation of the system will not be affected even though a node stops working.
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Transparency There is no requirement to establish a trust relationship among nodes because the operation of the whole system is open and transparent. Within the rules in the system, nodes cannot cheat each other.
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Collective maintenance The system is maintained by all nodes with maintenance functions. Everyone in the system participates in the maintenance work.
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Reliable database All the network nodes have the same copy of the blockchain ledger. It is invalid to modify the database of a single node because the system will compare the data records on each node automatically.
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Automation With the help of smart contracts, the resource and data sharing services could be automatically executed without human intervention.
3 Integration of the blockchain and the IoVs
Categories | Proposed | Implemented by | |
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IoV security | Access control | [29] | BlockAPP |
[30] | Intelligent vehicle trust point (IVTP) | ||
Message validation | [31] | Trust clustering mechanism for VANET (TCMV) | |
[32] | Distribute trust clustering mechanism for VANET (DTCMV) | ||
[33] | Blockchain-based traffic event validation (BTEV) framework | ||
Trust management | [34] | Vehicular announcement protocol echo-announcement | |
[35] | Anonymous cloaking region construction scheme | ||
[36] | Blockchain-based trust management with conditional privacy-preserving scheme (BTCPS) | ||
Certificate management | [37] | Blockchain-based privacy preserving authentication (BPPA) scheme | |
[38] | Decentralized key management mechanism (DB-KMM) | ||
[39] | A blockchain-based anonymous reputation system (BARS) | ||
[40] | Semicentralized traffic signal control (SCTSC) mode | ||
Data management | [41] | Miner selection and block verification solutions | |
[42] | Mobile crowd sensing (MCS) with blockchain | ||
[19] | A DQDA incentive mechanism | ||
Data monetization | [43] | Blockchain-based data trading and loaning system | |
[44] | Consortium blockchain-based data trading framework | ||
[45] | Consortium blockchain-based resource trading system | ||
Privacy preserving | [46] | A hybrid blockchain-PermiDAG | |
[47] | Blockchain-assisted privacy-preserving authentication system (BPAS) | ||
Revised IoV architecture | [48] | Blockchain-based software-defined VANET (block-SDV) framework | |
[49] | Blockchain-SDN-enabled architecture in 5G and fog computing systems |