## 2 Related Work  
Because of the openness and dynamic nature of the IoV, the communication process is faced with many security threats such as tracking, eavesdropping and so on. To improve the security and efficiency, many V2I authentication schemes have been proposed. Figure 1: System architecture. PKI (Public Key Infrastructure) is a system of technologies, processes, and policies that enable the secure management and distribution of digital certificates, which are used for authentication and encryption in various applications such as secure communication, digital signatures, and secure online transactions. In 2007, [PERSON] and [PERSON] [6] presented a PKI-based authentication scheme that uses a large number of pseudonyms to improve user privacy. [PERSON] et al. [7] also designed a PKI-based authentication scheme, which tests the validity of the broadcast beacon based on a PKI-based signature. [PERSON] et al. [8] proposed a pseudonymous authentication scheme to provide strong privacy, which permits the RSU to provide services of distributing certificates and vehicles to renew their certificates on road. Although using a pseudonym instead of a real name can protect the user's privacy, complete anonymity should not be allowed because malicious vehicles may perform malicious operations, such as sending forged messages or modifying the valid messages. To address this issue, [PERSON] et al. [9] proposed conditional privacy-preserving authentication (CPPA) using edge computing for vehicular ad hoc networks (VANETs). In their scheme, TA can track and obtain the real identity of vehicles by analyzing the pseudonym extracted from their messages and revocation malicious vehicles. [PERSON] et al. [10] provided a CPPA authentication scheme using short-term regional certificates. However, certificate exchange is a drawback in the authentication process. These PKI-based authentication schemes can improve the security of VANETs, but there are some obvious common defects. Firstly, the trusted authority needs to preload massive private/public keys and corresponding certificates in vehicles, which leads to some problems, such as limited vehicle storage, inefficient certificate management, and high deployment costs. Meanwhile, as the quantity of malicious vehicles grows, the speed and efficiency of searching for malicious vehicles in the Certificate Revocation List (CRL) will be affected. In order to solve the issues in managing certificates, in 1984, [PERSON] [11] presented identity-based (ID-based) cryptography (IBC), which uses the user's phone number or ID number as the public key and associates the user directly with the public key without the need for a certificate to associate the user identity with the public key. Thus, ID-based authentication protocols can solve the issues of certificate management. [PERSON] et al. [12] proposed an ID-based authentication scheme for VANETs and support batch verification. However, their scheme is not resistant to replay attacks and lacks non-repudiation. [PERSON] et al. [13] also proposed an anonymous authentication protocol with batch verification for VANETs. Because these schemes use bilinear pairings and asymmetric encryption, they have high computational costs. In order to improve the efficiency, [PERSON] et al. [14] designed an ID-based V2V and V2I authentication scheme without bilinear paring. Nevertheless, their scheme may divulge real identities, compromising privacy. The design of lightweight cryptographic protocols has garnered attention from researchers because V2I authentication protocols based on public key cryptography or bilinear pairs require high computational complexity. In 2019, [PERSON] et al. [15] presented a lightweight authentication scheme for VANETs without bilinear paring. In 2023, [PERSON] et al. [16] presented a lightweight physically secure authentication scheme in VANETs. Because RSU is installed in an unmanned environment, it is easy for attackers to capture and launch a series of attacks [17]; therefore, these two schemes cannot resist RSU captured attacks.