An Improved Lightweight Block Cipher Algorithm for Securing Resource-Constrained IoT Devices

The ever-expanding Internet of Things (IoT) landscape demands secure and efficient cryptographic solutions, especially for resource-constrained devices. With the explosion of IoT technologies across various sectors, securing these interconnected devices against sophisticated cyber threats has become paramount, mainly when they function under significant resource limitations such as limited computational power, memory capacity, and energy. This thesis investigates the development and evaluation of an innovative lightweight block cipher (LWBC) algorithm designed to enhance the security of resource-constrained IoT devices. The research is driven by the critical requirement to address the resource-constraint challenges through an extensive study and critical review of existing LWBC algorithms, the design of an improved LWBC framework, and empirical analyses of its performance and security.

To address the challenge of securing data communication in resource-constrained IoT devices, this thesis comprehensively analyses existing lightweight cryptographic solutions and identifies their limitations in IoT environments. By leveraging these insights, an innovative LWBC framework is proposed that prioritises resource efficiency and robust security within IoT constraints. Following the framework design, the research carefully designs and evaluates the proposed LWBC’s S-box using irreducible polynomials and affine transformations for security with minimal resources. Additionally, a P-box generation technique is introduced, utilising nonlinear feedback shift registers (NFSRs) to enhance the diffusion properties. Furthermore, a groundbreaking key management scheme has been designed using pre-distributed partial keys to address security concerns while minimising storage requirements and reducing communication-related energy consumption. Finally, the power consumption profile of the proposed LWBC is thoroughly evaluated and compared against established ciphers, demonstrating its suitability for resource-constrained IoT devices.

The proposed Lightweight Block Cipher (LWBC) has been thoroughly evaluated for performance and security using metrics such as energy consumption, memory usage, and resistance to cryptanalysis. The experimental results demonstrate that the LWBC reduces energy consumption by approximately 8% compared to Piccolo, one of the IoT block ciphers. Additionally, the LWBC maintains a low memory footprint, requiring only 1.4 KB of ROM, which is significantly smaller than popular IoT block ciphers. It reduces energy consumption by approximately 77% compared to PRINT and by 10% compared to PRESENT. Furthermore, empirical analysis validates the cipher’s resistance against various cryptanalysis attempts, solidifying its potential as a viable and secure solution for protecting data communication within IoT networks.

This thesis significantly advances IoT security by introducing a practical and secure cryptographic method called the LWBC framework. This framework addresses the unique restrictions of resource-constrained IoT devices. This research emphasises the critical need for cryptographic methods that strike a delicate balance: ensuring robust security against potential attacks while minimising resource consumption within the limited capabilities of IoT devices. The proposed LWBC framework fills a critical gap in current IoT security solutions and lays a strong foundation for future advancements in lightweight cryptography. By indicating the feasibility and efficiency of this approach, this thesis paves the way for developing even more efficient and secure cryptographic solutions, ultimately fostering a more secure and trustworthy landscape for the ever-growing world of IoT.