## 6 Conclusions and Future Work  
This study proposed and evaluated a method to secure communications in heterogeneous IoT networks by using a cryptographic algorithm based on elliptic curve cryptography (ECC), adapted to balance the security needs and performance requirements specific to IoT devices. The ECC algorithm, optimized for low-power devices (LPDs) and high power devices (HPDs), has demonstrated increased efficiency in key exchange and encryption. This study showed that, through specific optimizations, ECC can be used to ensure secure communications in IoT networks without significantly compromising energy consumption and hardware resources. The experimental tests validated the performance of the algorithm in real IoT environments, where a significant reduction in processing time and a minimal impact on energy consumption was observed, compared to other traditional cryptographic security methods. At the same time, it was found that the use of a key propagation scheme allows synchronization to be maintained between heterogeneous devices, thus limiting the vulnerabilities generated by various computing powers within the same IoT network. The energy efficiency and security of the ECC model make it particularly suited for IoT applications such as smart city infrastructure, where secure communication between distributed devices is critical, or wearable healthcare devices that require minimal power consumption while maintaining data confidentiality. Following the promising results obtained, future research directions will focus on aspects and limitations identified in this study. One of the main objectives will be the optimization of the ECC algorithm for extended resources, with the aim of allowing its implementation in an extended IoT network, having a significantly larger number of devices. This involves adjusting the processing and synchronization requirements so that the algorithm can work efficiently in an environment characterized by distributed and variable computing resources. Another important area of research will be the protection against side-channel attacks, which represent a major risk for the security of IoT devices. It is necessary to explore the integration of techniques to mitigate these attacks, to increase the resistance of devices to physical attacks that can compromise cryptographic keys. In this sense, testing these techniques in a real IoT environment will allow the identification of new and effective protection methods. In parallel, it will be necessary to address scalability and key management in complex IoT structures. A critical point in this regard is the development of decentralized key management mechanisms, which facilitate the exchange of secure information between devices, at the same time eliminating the unique points of vulnerability that appear in centralized systems. These solutions will have to meet the requirements of scalability and security as IoT networks expand. There will also be an emphasis on energy consumption analysis for hybrid deployments. They could combine the ECC algorithm with other energy-efficient cryptographic protocols, thus providing robust protection in a resource-constrained framework, ideal for low-power IoT devices. Such a study could offer solutions to achieve a balance between security and energy performance. Another important research area will focus on the development of dynamic authentication mechanisms for IoT networks. These mechanisms will have the role of continuously evaluating the risk profile of each IoT device, taking into account factors such as its location and the type of communication used. By implementing such adaptive mechanisms,the authentication process will be able to respond more effectively to risk variables, thus increasing the security of IoT networks and protecting them against unauthorized access or attacks based on abnormal behavior. Future simulations will focus on larger and more complex IoT networks to evaluate the scalability of the proposed ECC model.