With the rapid growth of the Internet of Things (IoT), ensuring secure communication between devices has become one of the most critical challenges in modern networks. Many existing solutions focus only on identity-based authentication, which is often insufficient against more advanced attacks such as spoofing or location-based intrusions. In this work, a new authentication model is proposed that combines blockchain technology, spatial verification through angular distance, and lightweight hybrid cryptography.
The idea behind this approach is simple but effective: instead of trusting a device only based on its identity, the system also verifies where the device is located. At the same time, blockchain is used to store authentication records in a secure and tamper-resistant way, while smart contracts automate the decision-making process. Simulation results show that the proposed method performs reliably even as the number of devices increases, while keeping computational and energy costs relatively low. This makes it suitable for real-world IoT environments.