Cryptology ePrint Archive: Report 2020/038

Bitstream Modification Attack on SNOW 3G

Michail Moraitis and Elena Dubrova

Abstract: SNOW 3G is one of the core algorithms for confidentiality and integrity in several 3GPP wireless communication standards, includ- ing the new Next Generation (NG) 5G. It is believed to be resistant to classical cryptanalysis. In this paper, we show that SNOW 3G can be broken by a fault attack based on bitstream modification. By changing the content of some look-up tables in the bitstream, we reduce the non- linear state updating function of SNOW 3G to a linear one. As a result, it becomes possible to recover the key from the keystream. To our best knowledge, this is the first successful bitstream modification attack on SNOW 3G. We propose a countermeasure which blows-up the number of candidate points for fault injection, making the presented attack infeasible in practice.

Category / Keywords: secret-key cryptography / SNOW 3G, stream cipher, fault attack, FPGA, bitstream modification, reverse engineering.

Original Publication (with major differences): Proceedings of the 2020 Design, Automation & Test in Europe Conf. & Exhibition (DATE’20)

Date: received 14 Jan 2020, last revised 7 Feb 2020

Contact author: micmor at kth se

Available format(s): PDF | BibTeX Citation

Version: 20200207:094230 (All versions of this report)

Short URL: ia.cr/2020/038


[ Cryptology ePrint archive ]