Research On Resource Optimization For Blockchain-Based Vehicular Edge Computing

According to the data report,the total number of cars in the world reached 1.2 billion in 2014,and it is expected to reach 2 billion in 2035.With the rapid development of the Internet of Vehicles(IoV),the number of vehicular application services has increased not only in number,but also in various types,such as self-driving,real-time navigation and augmented reality.In order to support a wide variety of vehicular application services,smart vehicles must be equipped devices with powerful computation,storage and communication capabilities.To ensure powerful performance,some expensive communication and computing units and sensors must be installed in these smart vehicles.However,those abundant on-board resources are not fully utilized.Data report shows that more than 70% of vehicles are parked for more than 20 hours per day.It can be seen that the densely distributed parking vehicles in the urban city are distributed pools with huge computing capabality.The purpose of this paper is to utilize the on-board resources of parked vehicles to carry out computation offloading,which will provide a powerful thrust for the implementation of intelligent transportation systems.Although leveraging parked vehicles for computation offloading has broad application prospects in the future smart city,it still faces many potential security threats and privacy leakages.Service requesters and parked vehicles face the risk of location tracking,data tampering,node emulation,remote hijacking,and privacy bre aches.In addition,existing researches apply a centralized approach to integrating on-board resources of parked vehicles.However,the centralized resource management is vulnerable to performance bottlenecks and is susceptible to single point of failure,remote hijacking,and distributed denial of service attacks.In order to solve the above challenges and resource optimization problems in parked vehicular computing,we propose a vehicular blockchain for open resources sharing in parked vehicular edge computing.The main work includes the following aspects:(1)We designs a feasible vehicualr blockchain system including crucial network netities for vehicle edge computing resources sharing.With the help of smart contracts,account registration,request posting,response record,task execution,task verification,and payment giving can be totally self-organized,which are computer programs automatically running and published to consensus nodes for auditing.(2)A subjective logic based Delegated Byzantine Fault Tolerates consensus mechanism is presented to enhance the consensus process in the blockchain.For secure communications,we leverage the multi-weighted subject logic to evaluate reputation values of parked vehicles with higher accuracy.The parked vehicles with high reputation value are pre-selected as the consensus nodes,which is responsible for auditing,verifying transaction records,and generating blocks.(3)We propose a contract-based incentive mechanism to model the decision process between the service requester and parked vehicles under information asymmetry scenario.Optimal contracts are designed to reward the parked vehicles with different parking behaviour and energy consumption for computation offloading while maximizing the service requester's utility.We present a Lagrange Multiplier Method based iterative algorithm to address the optimal contract decision problem.Numerical results demonstrate that the proposed contract-based incentive mechanism is effective and superior to other traditional schemes.