Research On Secure Information Dissemination With Access Control Policy Dynamic Adjustment In VANET

Vehicular ad hoc network(VANET)is considered as an important part of intelligent transportation,which has received widespread interests in both industry and academia in recent years.In VANET,nodes tend to send different information to specific vehicles by the means of broadcasting.Such information dissemination method provides traffic service to vehicles and enables vehicles to share information with each other.Because vehicles in VANET are able to enter and leave the network arbitrarily and get access to broadcasting data,it is easy for malicious vehicles to eavesdrop and tamper the data in wireless channel,which affects the privacy and security of other vehicles seriously.Meanwhile,lots of dissemination data is related to real-time traffic flow so that message sender is unable to determine an accurate distribution range because of its limited perception ability.If the information cannot be sent to the corresponding vehicles accurately,it will reduce the effects of traffic service which sends such information and even affect drivers' driving experience.Based on the existing researches,we propose an information dissemination scheme with dynamic access control policy adjustment in VANET.The model provides flexible and fine-grained access control policies,which improves the security and accuracy of information dissemination.It is helpful and meaningful for protecting the privacy and security of vehicles and improving the quality of information services.The main work of our paper is shown as follows:1.We briefly introduce the architecture of information dissemination in VANET,attribute-based access control model and attribute-based encryption algorithm.Based on these knowledge,we design an information dissemination scheme with access control in VANET.Our scheme utilizes attribute-based access control model to guarantee the security and accuracy of information dissemination.We firstly introduce the communication scenario and main steps of our scheme in detail.Later,we design an attribute-based access control framework in the scheme,including model formalization,default access control policy generation and attribute-based encryption.Our scheme is able to improve the security of information dissemination effectively.2.To solve the problem when message sender designs inaccurate policy,we introduce RSU and dynamic feedback mechanism to combine and adjust access control policy.With the help of perception ability of RSU,it generates access controlpolicy and integrates the policy designed by message sender.The combined policy is more comprehensive which makes up the shortcomings of message sender.The access control policy is pre-processed by attribute values normalization and policy formatting.When faced with the policy conflicts caused by mutli-party policy generation,we define the policy conflict.By means of confidence of message sender and RSU,we are able to adjust the value of conflicting attribute.Then,when RSU has a big error in perception because of sensor failure,a dynamic feedback mechanism is introduced to construct the best access control policy in each information dissemination scenario.We use optimal policies to adjust the confidences of the message sender and RSU,and to optimize the policy combination process.It helps to improve the accuracy of information dissemination.3.The security analysis of our information dissemination scheme is carried out to prove that our model is able to realize data confidentiality,protect privacy and resist collusion attacks effectively.We establish common information dissemination scenarios in VANET and design indexes to evaluate the effectiveness of access control policy in each scenario.We design comparative experiments to show the difference among policy designed by message sender,policy combined by RSU and policy combined by RSU based on feedback mechanism.We simulate traffic flow under different policies and prove the accuracy and effectiveness of our combined policies based on evaluation indexes.Finally,the performance analysis shows that the time loss of dynamic policy combination and adjustment is relatively low.And the total delay of our information dissemination scheme is controlled within a reasonable range,which is suitable for practical applications in the VANET.