Further improving security of Vector Stream Cipher

TL;DR

This paper introduces Vector Stream Cipher 2.1, an improved version of VSC 2.0, offering enhanced speed and security, demonstrating the effectiveness of permutation polynomials over rings of modulo 2^w in cryptography.

Contribution

The paper presents VSC 2.1, a new chaos cipher that advances the security and efficiency of previous VSC versions, showcasing the cryptographic utility of permutation polynomials.

Findings

VSC 2.1 is faster than VSC 2.0.

VSC 2.1 provides improved security against theoretical attacks.

Permutation polynomials over rings of modulo 2^w are effective in cryptography.

Abstract

Vector Stream Cipher (VSC) is a stream cipher which consists of permutation polynomial over a ring of modulo $2^w$. The algorithm for generating key stream is very simple and the encryption is very fast. Some theoretical attacks for VSC have been reported so far since the invention of VSC in 2004. Then, the authors proposed some improvements and developed "Vector Stream Cipher 2.0 (VSC 2.0)" to be immune against the theoretical attacks. In this paper, we propose further improvement of VSC 2.0 to publish as a new chaos cipher "Vector Stream Cipher 2.1 (VSC2.1)". VSC 2.1 is faster and more secure than VSC 2.0. Our result suggests that permutation polynomials over a ring of modulo $2^w$ are useful for cryptography.