As the integration of Internet of Things (IoT) into modern transportation systems accelerates, the convergence of smart mobility and ubiquitous connectivity brings both unprecedented opportunities and significant security challenges. Connected vehicles, autonomous systems, and intelligent traffic infrastructure rely on continuous data exchange, exposing them to risks such as cyber-attacks, unauthorized surveillance, and data misuse. This paper proposes a comprehensive, multi-layered framework to secure smart mobility by addressing core aspects of IoT and vehicular communication privacy. The proposed model integrates blockchain-based identity management, edge-based threat detection, and end-to-end encryption protocols tailored to vehicle-to-everything (V2X) ecosystems. Our research further explores privacy-preserving data aggregation and decentralized trust management for dynamic vehicular networks. Through simulations and case studies, the framework demonstrates robust resistance to common IoT threats, ensuring both functional integrity and user data confidentiality..