## Cryptology ePrint Archive: Report 2021/236

SNOW-Vi: an extreme performance variant of SNOW-V for lower grade CPUs

Patrik Ekdahl and Thomas Johansson and Alexander Maximov and Jing Yang

Abstract: SNOW 3G is a stream cipher used as one of the standard algorithms for data confidentiality and integrity protection over the air interface in the 3G and 4G mobile communication systems. SNOW-V is a recent new version that was proposed as a candidate for inclusion in the 5G standard. In this paper, we propose a faster variant of SNOW-V, called SNOW-Vi, that can reach the targeted speeds for 5G in a software implementation on a larger variety of CPU architectures. SNOW-Vi differs in the way how the LFSR is updated and also introduces a new location of the tap $T2$ for stronger security, while everything else is kept the same as in SNOW-V. The throughput in a software environment is increased by around 50\% in average, up to 92 Gbps. This makes the applicability of the cipher much wider and more use cases are covered. 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.

Category / Keywords: secret-key cryptography / SNOW, Stream Cipher, 5G Mobile System Security

Original Publication (in the same form): ACM WiSec 2021
DOI:
10.1145/3448300.3467829

Date: received 1 Mar 2021, last revised 25 Jun 2021

Contact author: alexander maximov at ericsson com

Available format(s): PDF | BibTeX Citation

Short URL: ia.cr/2021/236

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