HyeWon Mun  DongGyu Kwak

10.5626/JOK.2025.52.10.805

IoT system White-Box Cryptography SPN block cipher protected key injection lookup table generation

IoT environments, there is a significant risk of cryptographic key exposure, compounded by resource constraints that limit the use of traditional hardware-based key protection mechanisms. To address this issue, this paper introduces a method for generating protected key-based table for white-box cryptography tables. In this approach, an externally encoded protected key is inserted into the system to generate internal reference tables. The proposed algorithm ensures that the plain key does not reside in memory during the table generation process, effectively reducing the risk of key leakage during internal operations. The outputs of the algorithm are mathematically proven to be functionally equivalent to those produced by conventional table generation methods, while the size of the inserted protected key is reduced to approximately 1/270, enhancing both storage and transmission efficiency. Although the method is illustrated using AES-128, it is applicable to other SPN-based block ciphers as well. These findings indicate that the proposed scheme can serve as a secure and practical solution for key delivery and protection in resource-constrained IoT environments.