Research On Privacy Preservation Of Data Exchange In Intelligent Transportation Based On Blockchain

With the development of the 5th Generation Wireless Systems and the Internet of Things,intelligent transportation has now become the trend of transportation technology.Data exchange between vehicles and road side units under intelligent transportation benefits the driveless technology and helps to improve traffic safety as well as alleviate traffic congestion.However,there are still many security problems of intelligent transportation,among which privacy disclosure is the main security problem it is suffering now.Most of the existing privacy preserving schemes are based on the centralized architecture and require computations of high complexity or tamper-proof devices of high-cost,resulting much computation and storage cost,and there is less consideration of achieving expected privacy in low-density areas.To solve the above problems,this paper has carried out the following researches:(1)Propose a safe and efficient consortium Blockchain framework naming Trans Chain for data exchange in intelligent transportation,to alleviate the security threats including data tampering,single point failure and so on in centralized schemes as well as the safety and efficiency problems of existing blockchains.On one hand,the distributed and redundant storage of Trans Chain makes it possible to resist data tampering attacks.On the other hand,different from existing schemes,there is a cipher lottery algorithm in ours to randomly determines endorsers of each transaction on Trans Chain,so as to avoid the direct attack on endorsers and evenly allocate the endorsement tasks,which improves the security and efficiency of endorsement.Moreover,this paper has put forward a realtime transaction processing consensus process,where transactions can be sent to committers in real time after ordering,reducing time delay for appending transactions and further improving the timeliness of data on the chain.(2)Put forward an authentication protocol based on pseudonym for conditional privacy preserving,to tackle the low performance caused by high computation and communication overhead of existing schemes.Both identity and message authentication are involved in our protocol.The identity authentication has realized anonymity and interactivity by chameleon hash function and pseudonym.And there is an identity-based signature implementing on elliptic curve which can be batch verified in message authentication.Our protocol is not only independent on tamper-proof devices and computations of high complexity in security,but also greatly improve the efficiency through computations of lower complexity and batch verification,meeting the demand of privacy and performance in intelligent transportation.(3)Propose a motivation scheme for non-collaborative pseudonym changing based on mix zone,to solve the low privacy in low-density areas and inaccurate calculation of locations' privacy level.Considering the personalization of privacy preserving requirements among different vehicles,this paper has proposed the sensitiveness propagation network for fine-grained sensitiveness calculation,different from existing ones and according to which vehicles can decide whether to change pseudonym or not more accurately.By introducing the motivation mechanism of block-chain,we analyze the optimal strategy and reward function of rational vehicle peers on pseudonym changing and finally achieve at least K anonymous privacy preserving even in low density areas.Finally,this paper designs a scheme for securely data exchange in intelligent transportation based on Trans Chain.The comparison with other schemes indicates that the proposed one has achieved security and privacy without relying on tamper-proof devices or high-complexity computations.The simulation and experiments also show that our schemes mentioned above are better than others in terms of computation,communication as well as storage overhead and so on,which means higher feasibility under intelligent transportation.