Research On Message Authentication And Key Agreement Protocol In Vehicular Ad Hoc Networks

The vehicular ad-hoc networks(VANETs)are the application of mobile ad-hoc networks in intelligent transportation system.At present,the hotspot of VANETs research is security and privacy.VANETs are a wireless ad-hoc network.Its unique features include high mobility and rapid network topology changes,making it vulnerable to various external and internal attacks.These attacks have made security and privacy issues to be urgently addressed in the design of VANETs schemes.However,there are still security,privacy and efficiency issues in current VANETs schemes.Aiming at the above problems,this dissertation studies the message authentication and key agreement protocol of VANETs,and proposes two schemes.The main research contributions are as follows:(1)This dissertation proposes a trust based anonymous authentication scheme without certificate in the VANETs.Firstly,the scheme combines trust with traditional encryption schemes to improve the availability and reliability of the VANETs to protect privacy.Secondly,the scheme uses the advantages of elliptic curve encryption algorithm such as short key,high efficiency and high security performance to realize anonymous authentication of messages,and uses trust value to replace certificate revocation list.The scheme can encrypt the message sent by the node while completing the anonymous authentication function,so as to protect the privacy of the node information.Finally,the security of the scheme is proved.At the same time,the scheme adopts the method of aggregated signature and certificateless authentication,which effectively reduces the storage burden,computation and communication costs of the system.(2)This dissertation proposes a full session key agreement scheme based on chaotic mapping in the VANETs.Firstly,the key agreement process between the fog server and the group vehicle administrator in the system is described,and then the group key agreement process between the vehicle nodes in the group is described.Secondly,the scheme is based on Chebyshev chaotic mapping algorithm.Chebyshev polynomials are used to establish public multi-party key,which avoids modular multiplication index or scalar multiplication on elliptic curve.The use of chaotic mapping improves the computational efficiency of the scheme.Finally,the security analysis and performance analysis are carried out to prove the security and performance advantages of the scheme.