Enhanced Symmetric Cryptography Technique (ESCTGPU) for Secure Communication between the IoT Gateway and the public Cloud Environment

Abstract

The rapid expansion of the Internet of Things (IoT) has amplified the demand for secure and efficient communication with cloud platforms, where sensitive data is collected, processed, and stored. Conventional encryption standards such as DES and blowfish, though effective, are not ideally suited for resource-constrained IoT environments due to their computational overhead. To address this challenge, this paper proposes the Enhanced Symmetric Cryptography Technique to secure Gateway to Public Cloud (ESCTGPU), a lightweight yet robust block cipher specifically designed for IoT–cloud integration. ESCTGPU employs an 8-round structure with dual subkey mixing, adaptive bit rotations, and layered permutations, ensuring strong confusion and diffusion while minimizing execution time. Experimental evaluation using real IoT sensor payloads demonstrates that ESCTGPU achieves up to 40% faster encryption and decryption than DES and outperforms Blowfish in terms of efficiency, while attaining a measured 94% security strength, compared with 78% for DES and 84% for Blowfish. These results confirm that ESCTGPU offers a practical balance between speed and resilience, making it a suitable candidate for securing IoT–cloud communication where both performance and confidentiality are critical.