Disperse rotation operator DRT and use in some stream ciphers

TL;DR

This paper introduces a new disperse rotation operator (DRT) that enhances dispersibility and security in stream ciphers like HC-128, Rabbit, and Salsa20, improving output quality and resistance to differential attacks.

Contribution

The paper proposes the DRT operator, which improves dispersibility and security when replacing ROT in existing stream ciphers.

Findings

Significantly improved output stream quality in tested ciphers

Enhanced resistance to differential attacks in HC-128

Better dispersibility compared to traditional ROT

Abstract

The rotation operator is frequently used in several stream ciphers, including HC-128, Rabbit, and Salsa20, the final candidates for eSTREAM. This is because the rotation operator (ROT) is simple but has very good dispersibility. In this paper, we propose a disperse rotation operator (DRT), which has the same structure as ROT but has better dispersibility. In addition, the use of DRT instead of ROT has shown that the quality of the output stream of all three stream ciphers was significantly improved. However, the use of DRT instead of ROT in the HC-128 stream cipher prevents the expansion of differential attacks based on LSB.