Tree-Feistel Cipher Standard for IoT Communication System
Moatsum Alawida · IEEE Internet of Things Journal · 2025
As a key application within Internet of Things (IoT) engineering systems, secure communication protocols are essential for safeguarding sensitive information during data exchanges. Conventional and lightweight ciphers provide secure communication, but they often struggle to accommodate varying data sizes effectively while maintaining strong security. To address this limitation, the Tree-Feistel Cipher Standard (TCS) is proposed, a novel encryption scheme that integrates a hierarchical tree structure, an extended Feistel framework, and a substitution-permutation network (SPN). TCS employs a 512-bit block size and a 128-bit secret key, which undergoes adaptive operations to generate level-specific subkeys. A pre-processing phase employs a one-dimensional chaotic map to dynamically generate substitution-boxes (S-boxes) and permutation tables (P-tables), ensuring high nonlinearity and randomness. Encryption begins at level 3 with 64-bit blocks and leverages XOR operations, S-box lookups, and P-tables to provide strong confusion and diffusion. Experimental results demonstrate that TCS achieves superior performance compared to classical, lightweight, and state-of-the-art ciphers in terms of encryption speed, robustness, and security. TCS is especially suited for IoT and general communication scenarios, as validated through implementations on four platforms: a standard PC, a LiDAR sensor with Raspberry Pi, and two constrained devices (Teensy 3.6 and DOIT ESP32). Practical deployment within the OPC Unified Architecture (OPC UA) protocol further confirms TCS’s applicability in diverse computational environments.