## 2 Literature Review
The proposed balancing trust management and privacy preservation (BTMPP) technique uses the well-known bloom filter (BF)-based private set intersection technology to enable both trust management and robust condition privacy protection. Additionally, the suggested approach was enhanced in terms of accuracy, a powerful conditional privacy preservation capacity, and accurate trust management. The optimal path detection was performed for EM dissemination in VANETs. However, the RSU and base station are randomly placed and were not constructed properly, which increases the communication overhead. Vehicle networks are incorporated into the trust management system to spreadthe emergency message into space, the air, and the ground. By combining the advantages of the space, air, and ground segments in terms of coverage, flexibility, reliability, and availability, the proposed scheme can achieve precise trust management and strong conditional privacy preservation at the same time. This leads to improved trust management in space-air-ground-integrated vehicular networks. Then, a quantitative link between the fuzzification of reputation levels and the false positive rate may provide a strong mathematical basis for reaching a good equilibrium. Finally, the outcomes showed that the suggested plan is far better than the current methods in several ways. In [22], the routing decisions are only based on coverage. However, transmission ranges only are not efficient for estimating decision areas, which leads to complexity in message dissemination. The author of [23] used a secure message broadcast method with authentication to reduce message overhead in VANETs. The proposed effort focuses on a low-cost message authentication and secure message distribution mechanism for VANET. Messages are not authenticated by the vehicles themselves. The tasks of gathering, aggregating, verifying, and distributing messages to vehicles are within the purview of RSU. RSU may choose a few cars in its zone to act as the group leaders to gather aggregate messages from vehicles and save overhead. Finally, this system uses digital signatures based on public key cryptography to guarantee the validity and integrity of communications. The next hop selection and best forwarder selection, based on a single moving direction, leads to inefficient emergency message dissemination. The authors of [24] proposed using an artificial intelligence-enhanced interplanetary file system (IPFS) to securely manage messages in automotive energy networks. An interplanetary file system was first integrated with the RSU to store data delivered by cars for communication purposes. Additionally, the true identities of the automobiles guarantee that the privacy needs of the owners are met. Then, in the third tier of BC, the data hashes saved in IPFS are stored, along with a mild vehicle trustworthiness check. The suggested method successfully separates the issues of processing time and storage overhead by storing data hashes on the network as opposed to real data. Here, intelligent IPFS was used for cluster formation. However, it assumes that the same points are distributed about the mean, which leads to reduced stability, reliability, and energy efficiency. The authors of [25] proposed a secure multi-hop secure message transmission in VANET based on smartphone platforms. For example, the goal of the Automotive Connectivity Development Alliance, which aims to develop smartphone-centric vehicle connectivity solutions, is to focus on connected vehicle solutions for problems arising from vehicle-to-infrastructure (V2I) communications. The work primarily focused on the possibility of using smart devices to send messages between two vehicles. To solve the research gap, the authors provided a platform entirely contained inside the device for secure multi-hop message distribution. The findings introduced a cryptographic system appropriate for VANET that ensures data integrity and node authentication.