The rapid digitalization of transport infrastructures and the development of smart mobility concepts have significantly increased the level of interconnectivity among vehicles, sensors, traffic management centers, and digital control platforms. In this context, communication security has become a critical component for ensuring operational continuity and safety within Intelligent Transportation Systems (ITS). This paper investigates the role of secure communication protocols in enhancing the cyber resilience of digital transport infrastructures and proposes an architecture based on secure handshake mechanisms and post-quantum cryptographic solutions. The methodology involves the modeling of an intelligent transport infrastructure and the assessment of cyberattack scenarios affecting communication performance. The results demonstrate that the integration of advanced security mechanisms reduces vulnerabilities associated with connected systems and improves service continuity. The findings emphasize the importance of adopting resilient communication architectures capable of addressing future cybersecurity challenges arising from the evolution of quantum computing technologies.