Enhanced Security and Performance through Permutation-Byte Key Cipher with Reduced-Round AES

Abstract

This paper introduces the Permutation-Byte Key Cipher with Reduced-Round AES (PBKC-RRAES), a novel enhancement of the Advanced Encryption Standard (AES) designed to significantly improve both security and performance. The proposed algorithm integrates key modifications, including (a) the replacement of the MixColumns function with a bit permutation technique, (b) the addition of AddRoundKey operations between cipher states, (c) enhanced byte substitution operations and round constant additions in the key schedule algorithm before key expansion, and (d) a reduction in the number of rounds from 10 to 6. These innovations result in superior diffusion properties and heightened sensitivity to plaintext changes, as evidenced by a 54.214% avalanche effect, surpassing the standard 50% threshold. Performance evaluations reveal a 26.90% improvement in encryption time and a 22.73% improvement in decryption time, alongside throughput enhancements of 43.07% in encryption and 34.26% in decryption compared to the original AES. These results show that PBKC-RRAES is an effective alternative for cryptographic algorithms, offering better security and faster processing for data encryption and secure environments. Essentially, PBKC-RRAES replaces MixColumns with a new bit permutation to enhance diffusion, ensuring even small changes in plaintext produce significantly different ciphertext. Interleaved AddRoundKey operations add complexity for reverse engineering. Improved byte substitution and modified round constants facilitate dynamic key evolution with each round. With the number of rounds reduced from 10 to 6, these transformations strike a balance between speed and security, making the algorithm ideal for diverse computing environments, and a strong candidate for secure communications. This innovative approach represents a significant step forward in the evolution of lightweight, yet highly secure, cryptographic mechanisms.