The domain of the Internet of Things (IoT) confronts pivotal challenges in ensuring security, efficiency, and proficient energy management due to the expansive, dynamic, and resource-constrained nature of IoT environments. Encryption stands as a cornerstone in fortifying IoT security; nevertheless, its seamless integration faces hurdles of adaptability, overhead imposition, and power optimization. This chapter introduces an innovative cryptographic framework meticulously designed to enhance power efficiency within IoT devices. Specifically tailored for operation in either resource-constrained or low-resource IoT devices, this framework addresses the critical imperative to optimize energy consumption while maintaining a robust balance between security and efficiency. The framework incorporates a dynamic cryptographic mechanism that adjusts encryption parameters based on available power resources and distances between communicated nodes. To evaluate its performance, the proposed framework underwent rigorous evaluation using the OMNeT++ simulator. The results revealed substantial improvements in encryption time, reduced power consumption, and extended overall node lifespan compared to employing ciphers with fixed encryption parameters. The highlighted efficiency emphasizes its suitability for deployment in power-constrained or real-time scenarios.