In today's interconnected world, the increasing connectivity and data exchange in fields such as mobile cyber-physical systems (MCPS) and the internet of things (IoT) create a growing need for secure communication and data protection. Traditional security protocols and blockchain technologies may pose disadvantages in terms of performance and resource usage, especially for resource-constrained devices. This study proposes a comprehensive model that integrates a lightweight and quantum-resistant security protocol with a directed acyclic graph (DAG)-based blockchain structure for resource-constrained MCPS applications. The model is demonstrated using connected vehicles as an example of an MCPS application. The proposed protocol ensures secure communication and data integrity by employing quantum-resistant symmetric and asymmetric encryption. The DAG-based blockchain structure is utilized to reduce computational workload and enhance scalability in these devices. The blockchain is encrypted with AES-256 and hashed with SHA-256. Experimental results demonstrate that the proposed protocol and its integration with a DAG-based blockchain can provide a secure and efficient communication environment for MCPS applications. Security analysis reveals that the protocol is resilient against various attacks, including man-in-the-middle (MITM), denial-of-service (DoS), replay attacks, brute force attacks, and quantum attacks.