Hierarchical Hybrid Trust Management Scheme in SDN-Enabled VANETs

Table 1

Abbreviations.

Abbreviation	Description
RSU	Roadside unit
BS	Base station
OBU	Onboard unit
TM	Trust model
CA	Certificate authority
DTM	Data-oriented trust model
ETM	Entity-oriented trust model
CTM	Combined trust model
EvN	Evaluator node (information receiving vehicle)
ST	Inter-vehicular subjective trust
STW	Subjective trust weight
OTV	Original trust of vehicle
RT	Inter-vehicular recommendation trust
RW	Role-based trust weight
NT	Neighbor trust
SP	Trust opinion of neighbors
DC	Distance coefficient of RSU
	Similarity between node i and node j
IT	Infrastructure trust
HT	Hybrid trust