  With the fast expanding scale of vehicular networks, vehicular edge computing
(VEC) has emerged and attracted growing attention from both industry and
academia. Parked vehicles (PVs) have great potential to join vehicular networks
for sharing their idle computing and networking resources. However, due to the
underlying security and privacy threats, it is challenging to fairly motivate
PVs for resource sharing in an efficient and secure way. In this paper, we
propose a permissioned vehicular blockchain for secure and efficient resource
sharing in VEC, namely, Parkingchain. We first design smart contract to achieve
secure resource sharing and efficient service provisioning between PVs and
service requesters (SRs). A multi-weight subjective logic based delegated
Byzantine Fault Tolerance (DBFT) consensus mechanism is presented to improve
the consensus process in Parkingchain. Further, we design a contract
theory-based incentive mechanism to model the interactions between SR and PVs
under asymmetric information scenario. Finally, numerical results demonstrate
that the proposed incentive mechanism is effective and efficient compared with
existing schemes.
