WG: A family of stream ciphers with designed randomness properties

Abstract

In this paper we present a family of stream ciphers which generate a keystream with ideal two-level autocorrelation. The design also guarantees other randomness properties, i.e., balance, long period, ideal tuple distribution, and high and exact linear complexity. We discuss how these properties are achieved by the proposed design and show how to select various parameters to obtain an efficient stream cipher for the desired security level. We also show that the proposed generators are secure against time/memory/data tradeoff attacks, algebraic attacks and correlation attacks. Finally we present WG-128 1 WG-128 is a slightly modified version of the WG stream cipher which is a phase 2 candidate in profile 2 of the ECRYPT stream cipher project: eSTREAM. See http://www.ecrypt.eu.org/stream/ 1 as a concrete example of a WG stream cipher with a key size of 128 bits.