Hierarchical Hybrid Trust Management Scheme in SDN-Enabled VANETs

Algorithm 1

Inter-vehicular trust calculation.

	Input LTD, OTV, vehicle ID, ROVij, QODij
	Output ST, RT
	if vehicle i receives interactive information from vehicle j then
	Calculate the distance between nodes and obtain the STW value according to equation (1)
	Check the local trust database (LTD) of vehicle i
	if IDj ∈ LTDi then
	Search OTVij
	else
	Take OTVini as the OTV value of vehicle i to vehicle j
	end if
	Upgrade the OTV information of vehicle i
	Calculate the ST of vehicle j using equation (3)
	if ROVij ≥ ROVthre then
	ROVij ⟵ ROVij + λ
	else
	ROVij ⟵ ROVij − μ
	if QODij ≥ QODthre then
	QODij ⟵ QODij + λ
	else
	QODij ⟵ QODij − μ
	end if
	end if
	Use equation (6) to calculate the trust score SP between vehicles
	Calculate the value of NT according to the value of SPij using equation (5)
	Determine the role type of vehicle j and use equation (4) to find RW
	Use equation (7) to calculate the RT of vehicle i to vehicle j
	end if