A Residue Number System-Based Architecture for Enhancing the Data Encryption Standard in Resource-Constrained Environments
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aAbstract
Legacy Industrial Control Systems (ICS) continue to rely on lightweight cryptographic mechanisms due to hardware and computational constraints. Although the Data Encryption Standard (DES) remains attractive for such environments because of its simplicity. However, its susceptibility to modern cryptanalytic attacks affects its security effectiveness. This study presents the Data Encryption Residue Number System (DERNS) algorithm, an enhanced DES encryption scheme that integrates Residue Number System (RNS)-based key obfuscation together with pre-whitening and post-whitening operations into the DES encryption process. The development of the DERNS algorithm involved the analysis of the conventional DES structure, the integration of RNS-based key obfuscation techniques, the derivation of whitening masks from the obfuscated key, and the incorporation of pre-whitening and post-whitening operations into the DES encryption and decryption processes. The DERNS algorithm was implemented and evaluated against the standard DES algorithm using plaintext sizes ranging from 16 to 4096 bytes. Security performance was validated using entropy, avalanche effect, Strict Avalanche Criterion (SAC), Bit Independence Criterion (BIC), and key sensitivity, while the computational performance was evaluated using encryption time, decryption time, total execution time, throughput, and memory utilization. Experimental results show that DERNS maintained entropy values comparable to DES and close to the ideal value of 8 for larger plaintext sizes. The developed DERNS algorithm achieved improved avalanche characteristics, strong SAC and BIC compliance, and significantly enhanced key sensitivity. Performance evaluation further demonstrated superior scalability, with lower total execution times, higher throughput, and reduced memory utilization for moderate and large plaintext sizes compared with standard DES. The results indicate that the integration of RNS-based transformations enhances both the security and computational efficiency of DES without compromising its lightweight structure. The study concluded that DERNS provides a practical and scalable cryptographic enhancement suitable for legacy and resource-constrained industrial environments which requires secure and efficient data encryption.
