## 4 Privacy-Preserving Optimization Based on Advanced CH Selection (P2O-ACH)
### Enhanced ROA-Based CH Selection
By using an optimization-based CH selection process, the congestion is reduced. The enhanced ROA model solves the complication in the high-speed VANET network, which reflects in the trustworthiness of the network. Through the privacy-preserving mobility model, each data transmission at each instant of time is protected, and the data are free from the malfunction that occurred in the eternal environment. Results of the proposed P2O-ACH are found effective when compared with the GWO-CH, ACO-SCRS, and QMM-VANET. By the use of an enhanced ROA-based CH selection method, the energy consumption is reduced, which leads to improving energy efficiency and the lifetime of the network. The privacy-preserving mobility model provides security, especially during the process when the nodes leave the cluster during the process of communication and when the nodes try to join in the other cluster. Then, the routing list of all the clusters is securely updated to the SINK. From the simulation analysis, according to the number of vehicles, it is proven that our proposed P2O-ACH produced around 200 Joules with higher efficiency, 200 joules lower energy consumption, around 800 packets lower loss, around 2000 packets lower overhead, around 10% higher packet delivery ratio, and around 400 Kbps high throughput when compared with the earlier approaches, such as GWO-CH, ACO-SCRS, and QMM-VANET. According to the speed variation, the differences achieved are very low and normal. Our proposed research is highly beneficial to the community because it is a highly-cost effective method, which can achieve high energy efficiency and high security as well. For vehicular communication, the proposed method can provide an effective experience in communication. In future work, many scenarios will be introduced and the performance of the network will be analyzed using the proposed P2O-ACH method. Investigation, N.F.A. and N.F.S. ; resources, D.A.M. ; writing--original draft preparation, A.A. and S.Z.H. ; methodology, H.M.H. ; software, A.S.A. ; supervision and writing--review and editing, A.H.A. ; visualization, M.H.H. ; visualization, M.A.J. ; project administration, F.H.A. ; formal analysis and funding acquisition, N.F.A. and A.D.A. and funding acquisition W.E.-S. All authors have read and agreed to the published version of the manuscript. This research received no external funding. Not applicable. The authors would like to acknowledge the support of Prince Sultan University for paying the Article Processing Charges (APC) of this publication. The authors declare no conflict of interest. ## References

* (1) [PERSON]; [PERSON]; [PERSON]; [PERSON] Advances in position based routing towards ITS enabled FoG-oriented VANET-A survey. _IEEE Trans. Intell. Transp. Syst._**2020**, _21_, 828-840. [CrossRef]
* (2) [PERSON]; [PERSON]; [PERSON]; [PERSON]; [PERSON]; [PERSON] Accident management system based on vehicular network for an intelligent transportation system in urban environments. _J. Adv. Transp._**2018**, _2018_, 6168981. [CrossRef]
* (3) [PERSON]; [PERSON]; [PERSON]; [PERSON]; [PERSON] A smart energy-based source location privacy preservation model for Internet of Things-based vehicular ad hoc networks. _Trans. Emerg. Telecommun. Technol._**2020**, _33_, e3973. [CrossRef]* [PERSON] et al. (2019) [PERSON]; [PERSON]; [PERSON]; [PERSON] The Convergence of IoE and Blockchain: Security Challenges. _IT Prof._**2019**, _21_, 26-32. [CrossRef]
* [PERSON] et al. (2019) [PERSON]; [PERSON]; [PERSON]; [PERSON] [PERSON] A Novel Intelligent Cluster-Head (ICH) to Mitigate the Handover Problem of Clustering in VANETs. _Int. J. Adv. Comput. Sci. Appl._**2019**, _10_, 0100627. [CrossRef]
* [PERSON] et al. (2022) [PERSON]; [PERSON]; [PERSON] Self-Adaptive Efficient Dynamic Multi-Hop Clustering (SA-EDMC) Approach for Improving VANET's Performance. _Int. J. Interact. Mob. Technol._**2022**, _16_, 136-151. [CrossRef]
* [PERSON] et al. (2015) [PERSON]; [PERSON]; [PERSON]; [PERSON]; [PERSON] VANET modeling and clustering design under practical traffic, channel and mobility conditions.