Design And Implementation Of Information Release System Based On Digital Certificate

With the continuous development of China’s economy and society,the number of cars continues to rise,and the Internet of Vehicles technology has also been rapidly developed.As an important part of the Internet of Vehicles,the CMS(changeable message signs)is responsible for providing drivers with accurate road condition information.Therefore,it is very important to ensure the security of information on CMS.This project is based on the PKI(Public Key Infrastructure)certification system to design the information security system of the CMS.It mainly involves three modules:host computer,server and information board.In the host computer module,for the data information to be played and the message information to be controlled on the screen,we use the signature and envelope API to make digital signature and perform digital envelope operations to ensure the security and integrity of the data.At the same time,the host computer can also provide a digital signature verification service to verify the integrity of the received response message.The design of the host computer is made using MFC,which mainly includes three interfaces required by the business: screen control,data delivery,testing and updating.When sending data,the message consists of fields in accordance with the secure interactive interface protocol designed by ourselves,and the data is sent through the CURL tool for the server to decrypt and verify.Among them,the asymmetric keys used for signature and digital envelope operations are all certified by the digital certificate issued by the CA(Certificate Authority)to ensure their reliability.The server module runs in the synchronous and asynchronous card of ARM framework.We built an HTTP server program in the synchronous and asynchronous card to parsed the data according to the secure interactive interface protocol,and then decoded,de-enveloped and checked the received data.The HTTP server program is developed based on the open source architecture,which adds a number of interactive interfaces to interact with the host computer.The server is developed on the virtual machine and transplanted to the ARM environment for testing and use.The signature verification and de-envelope work will call the API provided in the external TF card.After the processing is completed,the server will feedback the response result to the host computer.If required,a signature will be attached to the response and sent to the host computer for verification.At the same time,The server will record the business requirements put forward by the verified data,and send the data to the variable information board according to the traffic protocol in order to complete the control of the screen or the broadcast of information.The whole development process was carried out in the Ubuntu 14.04 virtual machine environment,and finally transplanted to the synchronous and asynchronous card through cross-compilation for testing.The entire security system combines encryption and decryption,data application,network server and many other aspects,and has successfully tested the product.It can effectively guarantee the security of the information board travel information system.