Table 2.

Blockchain for perception layer issues in vehicular IoT.

Purpose	Publication	Research Summary
Positioning	Li et al. [57]	A blockchain-based technology to store and share the evolution of positioning errors in order to protect the security of cooperative vehicles.
Trust management	Yang et al. [58]	A blockchain-based decentralized trust management system where RSUs work as miners to create blocks; a combination of PoS and PoW is used in achieving consensus.
	Yang et al. [59]	A traffic message validation mechanism, which is based on blockchain, that uses a PoE consensus concept.
	Liu et al. [60]	A blockchain-based trust management scheme with the consideration of vehicle privacy.
	Xie et al. [61]	A trust management approach for real-time video report in SDN-enabled VANETs.