Open Access

ARTICLE

Improved RC6 Block Cipher Based on Data Dependent Rotations

Osama S. Faragallah^1,*, Ibrahim F. Elashry², Ahmed AlGhamdi³, Walid El-Shafai⁴, S. El-Rabaie⁴, Fathi E. Abd El-Samie⁴, Hala S. El-sayed⁵, Mohamed A. Elaskily⁶

1 Department of Information Technology, College of Computers and Information Technology, Taif University, P.O. Box 11099, Taif, 21944, Saudi Arabia
2 Department of Electrical Communications, Faculty of Engineering, Kafrelsheikh University, Kafrelsheikh, Egypt
3 Department of Computer Engineering, College of Computers and Information Technology, Taif University, P.O. Box 11099, Taif, 21944, Saudi Arabia
4 Department of Electronics and Electrical Communications, Faculty of Electronic Engineering, Menoufia University, Menouf, 32952, Egypt
5 Department of Electrical Engineering, Faculty of Engineering, Menoufia University, Shebin El-Kom, 32511, Egypt
6 Department of Informatics, Electronic Research Institute (ERI), Cairo, Egypt

* Corresponding Author: Osama S. Faragallah. Email:

Computers, Materials & Continua 2022, 70(1), 1921-1934. https://doi.org/10.32604/cmc.2022.019798

Received 26 April 2021; Accepted 08 June 2021; Issue published 07 September 2021

Abstract

This paper introduces an Improved RC6 (IRC6) cipher for data encryption based on data-dependent rotations. The proposed scheme is designed with the potential of meeting the needs of the Advanced Encryption Standard (AES). Four parameters are used to characterize the proposed scheme. These parameters are the size of the word (w) in bits, the number of rounds (r), the length of the secret key (b) in bytes, and the size of the block (L) in bits. The main feature of IRC6 is the variable number of working registers instead of just four registers as in RC6, resulting in a variable block size for plaintext and ciphertext. The IRC6 cipher is designed to improve the robustness against attacks by increasing the diffusion for each round and providing greater security with fewer rounds. The effectiveness of the proposed IRC6 scheme is verified against theoretical attacks. The proposed IRC6 scheme depends on full diffusion and confusion mechanisms regardless of the utilized block size. The proposed IRC6 scheme saves 70% of the encryption time and 64% of the decryption time of RC6. The simulation results prove that the IRC6 achieves a better encryption/decryption time compared to the traditional RC6. Therefore, the proposed IRC6 is anticipated to fulfill the market needs and system security requirements.

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Keywords

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