# Secure and Efficient High Throughput Medium Access Control for Vehicular Ad-Hoc Network
## 2 Literature Review  
A comprehensive survey of the existing security design is carried out for provisioning security to VANET in this section. In [35] presented an efficient pseudonymous authentication design to protect user personal information. They presented multiple hierarchies of pseudonyms based on user sessions. A session with smaller timestamp pseudonyms is used for communication among semi-trusted authorities and longer session timestamp pseudonyms are used for communication among vehicles. Their model overcomes the storage and computation overhead of certificate revocation lists and group-based approaches. Experimental outcomes show it minimizes end-to-end package delay and delivery ratio. However, they consider only honest but curious server and suffer from trust-related issues concerning certificate authority. The study in [40] proposes a geo-routing protocol for the introduction of the Location Errors Record (LER-GR), evaluating the position error of neighboring vehicle compounds using the error calculation method according to the Rayleighdistribution and development of position prediction and correction technology based on Kalman filter and prediction of the position of neighboring vehicles. The authors in [41] use the reconfigurable intelligent surface (RIS) to enhance the Physical Layer Security (PLS) in VANET. However, they have presented two network system models: the first is vehicle-to-vehicle communication through RIS and source-based access points, and the second is information of VANET with RIS based relay deployed in the building as mentioned in [42]; the signature verification takes around 20 ms by the onboard unit at a 400 MHz processor. This might not be a problem in sparse areas, but in dense areas, it could cause significant delays in the message verification process. The Certificate Revocation List (CRL) is another limitation of the pseudonym methods, i.e., certification authority creates a set of public vehicle key certificates. Then, the vehicle uses the private key to sign the beacon and broadcasts the signal using the corresponding public key certificate. However, in the case of revocation, you need to add all certificates of revoked users to the CRL. Hybrid Intrusion Detection System (D2H-IDS) is used to separate trusted service requests from invalid requests that were created during malicious attacks used to prevent security attacks [43]. Reference [44] designed an approach to optimize scheduling, routing, and access control while reducing network congestion, securing a slot allocation for reserved traffic, securing network reliability, and maximizing approval of network flows. Reference [45] presented a reliable and secure connection to reduce unnecessary communication between edges by relying on the transport protocol between nodes in smart cities. Reference [46] proposed HIBS-K Sharing, given different types of communication devices, which is suggested to share a hierarchical identifier-based signature key for Automotive vehicles. Similarly, the authors in [47] presented a hardware-based security design to provide security to address the trust-related issue of [35]. They considered a hybrid security model and presented a design to preserve the privacy of vehicular communication. Their model considers dual authentication based on different IoV scenarios. Firstly, the onboard unit computes a temporary encryption key and anonymous identity to initialize the authentication session. Then, the trusted authority can evaluate the authorized vehicles' anonymous and real identities. The vehicle reputation is evaluated based on past transmission based on which a session key can be established. Their model preserves privacy and minimizes key exchange overhead. Nonetheless, the tamper-proof device may not guarantee all the VANET security requirements [36] and incurs communication overhead. To address this, ref. [36] presented a secure privacy-preserving authentication scheme.