QRNGs and post-Quantum VPNs are employed in this study to examine the ability of quantum cryptography in securing IoT interactions. QRNGs generate the keys based on quantum mechanics that are almost impossible to guess. This makes them safer compared to the traditional approaches to undertaking the exercise. These keys ensure that IoT networks can be used to send and receive data securely eradicating issues that relate to quantum computing. The application of post-Quantum VPNs helps to defend communication channels from being attacked with the help of quantum algorithms. The use of QRNGs and post-Quantum VPNs in the IoT devices gives a robust protection system against various cyber threats. This paper considers several performance indicators, including the degree of encryption, response time, multinomiality, and power consumption abilities. That is to say, it demonstrates that this cryptographic method significantly enhances the IoT communications' resilience to quantum threats. The findings reveal that quantum cryptography is effective in securing IoT networks in the future. © 2025 Elsevier B.V., All rights reserved.