Study On Privacy Preservation Technology In VANET

VANET(Vehicle Ad Hoc Network)has drawn extensive attention because it can not only improve traffic safety and efficiency but also bring more comfortable driving and riding experience for passengers.However,the open-access environment and limited network bandwidth in VANET lead to many critical and challenging security issues.In order to ensure the security of the communication among the units in VANET,researchers have proposed many authentication schemes for VANET.However,the efficiency of such schemes and the privacy preservation of the vehicle units still needs further study.First of all,this thesis introduces a taxonomy of authentication schemes,and discuss the advantages and disadvantages of the existing schemes.Then,the thesis outlines the security requirements and challenges in VANET based on the overall framework.Secondly,this thesis proposes a new efficient certificateless short signature(CLSS)scheme based on the hard problems of k-CAA and k-BDHI so as to provide an efficient cryptography algorithm to fulfill the authentication between RSU(Road-Side Unit)and OBU(On-Board Unit).The analysis shows that the proposed scheme is not only existential unforgeable against adaptive chosen message and ID attacks in the random oracle model(ROM)but also has higher efficiency comparing with other similar schemes.In addition,the shorter signature length and higher authentication efficiency of this scheme makes it more suitable for VANET environment with limited communication bandwidth.Thirdly,on the basis of analyzing of a number of existing authentication schemes,this thesis proposes a concept of regional management of RSUs.To ensure the privacy preservation of the users and the security of communication among the units in VANET,the thesis also designs a V2 R mutual authentication protocol based on the public key cryptosystem via the regional management.Moreover,this thesis demonstrates the high efficiency of the proposed scheme by experimental simulation and the comparison with other selected schemes.The proposed scheme has the following advantages:(1)RSU authenticates OBU.This authentication process is based on the new proposed CLSS scheme and concealed the identity of users completely by disposing the OBU's real identity and public key.On one hand,the OBU replaces its real identity by a pseudonym during the signature process,and this pseudonym can be changed by the sending message.On the other hand,the user has a pair of his/her own public and private keys.In order to prevent the fixed public key from exposing his/her real identity,the user will dispose it randomly before sign the sending message.And then,broadcast the signed message to the surroundings.(2)OBU authenticates RSU.When RSU verified OBU successfully,it can decrypt OBU's pseudonym by ECC-based private key and decryption algorithm,which are selected by TCC,to obtain the signer's real identity.RSU and OBU set the identity information as the shared secret key between them.Then,OBU verifies RSU by calculating and comparing the message authentication code(MAC)with the received MAC from RSU.