Paper 2021/236

SNOW-Vi: an extreme performance variant of SNOW-V for low-end CPUs

Patrik Ekdahl and Thomas Johansson and Alexander Maximov and Jing Yang

Abstract

In this paper we propose a faster variant of SNOW-V, called SNOW-Vi, that can perform fast enough not only in cloud settings but also on low grade CPUs. The increase in software performance is around 50% in average, up to 92 Gbps. This makes the applicability of the cipher much wider and it covers more use cases. SNOW-Vi differs in the way how the LFSR is updated and also introduces a new location of the tap $T2$ for a stronger security, while everything else is kept the same as in SNOW-V. The security analyses previously done for SNOW-V are not affected in most aspects, and SNOW-Vi provides the same 256-bit security level as SNOW-V.