Research On Efficient Certificateless Authentication Schemes In Vehicular Ad-Hoc Networks

As a new application form in the field of Intelligent Transportation,Vehicle Ad-hoc Network(VANET)has been paid much attention and explored in recent years because of its help to improve traffic conditions and road safety management,and it is expected to provide ubiquitous,ultra-reliable and low-latency transmission.Due to the openness of wireless links,however,communication in VANET is vulnerable to unauthorized access and various types of security attacks,such as eavesdropping,tampering and forgery,which can lead to dangerous situations.In addition,the high mobility of vehicles and the sending and receiving of a large amount of road condition data in a short time also put forward higher requirements for the rapid response of on-board devices,roadside and cloud devices.Therefore,data security and privacy protection under severe delays are critical for wide deployment of VANET.To solve the high efficiency and safety problems,this paper studied and analysed the system model and security requirements of VANET,and applied certificateless technology to the design of VANET authentication scheme with high security and lightweight requirements.The research results are summarized as follows.(1)The existing VANET authentication schemes failed to address critical security flaws in application scenario and the problems related to computational overhead,making them unable to be executed on the on-board equipment with limited computing resources.Therefore,a certificateless privacy-preserving authentication scheme against collusion attacks for VANET is put forward.Firstly,a public key aggregation equation analysis is proposed,which shows that some existing schemes cannot satisfy existential unforgeability,and the essential reason for successful attack by the adversaries is summarized.Secondly,a more rigorous security notion for certificateless aggregate signature is redefined.By introducing online/offline signing method and exploiting the collision-resistance property of the hash function,a secure and efficient privacy-preserving authentication scheme for VANET is constructed under the new model.It guarantees that the signatures aggregated by roadside units are valid if and only if the signatures of all on-board units are valid.Finally,formal security proof is given to ensure the correctness and robustness of the scheme.(2)For the problems of high communication delay and lack of effective management of dynamic vehicle updates in the existing road condition monitoring scheme for VANET,this paper presented an efficient certificateless dynamic group signature road condition monitoring scheme based on fog-assisted for VANET.Firstly,based on group signature with message recovery capabilities,this scheme implements fast authorization reporting and authentication.Secondly,a batch join or revocation mechanism it adopted by this scheme to improve the efficiency of dynamic member updates,ensuring that the fog server can effectively validate messages even if there is a large amount of traffic congestion.Moreover,each vehicle could freely join and leave different groups with lightweight modular multiplication operations.Finally,detailed theoretical analysis shows that this scheme can provide multiple security guarantees and meet the strict delay requirements in dynamic VANET environments.The performance evaluation experiment results based on the Intelli J IDEA and JPBC integrated environment show that the proposed two schemes have better overall performance in terms of computing cost and communication efficiency than relevant schemes in this field.Through a large number of experimental simulations conducted on SUMO and OMNET++ integrated platforms,it is verified that the proposed schemes have a very low average end-to-end communication delay and meet the strict requirements for latency in a highly dynamic VANET environment.