Cryptology ePrint Archive: Report 2017/1223

Generic Low-Latency Masking in Hardware

Hannes Gross and Rinat Iusupov and Roderick Bloem

Abstract: In this work, we introduce a generalized concept for low-latency masking that is applicable to any implementation and protection order, and (in its most extreme form) does not require on-the-fly randomness. The main idea of our approach is to avoid collisions of shared variables in nonlinear circuit parts and to skip the share compression. We show the feasibility of our approach on a full implementation of a one-round unrolled Ascon variant and on an AES S-box case study. Additionally, we discuss possible trade-offs to make our approach interesting for practical implementations. As a result, we obtain a first-order masked AES S-box that is calculated in a single clock cycle with rather high implementation costs (60.7 kGE), and a two-cycle variant with much less implementation costs (6.7 kGE). The side-channel resistance of our Ascon S-box designs up to order three are then verified using the formal analysis tool of [BGI+18]. Furthermore, we introduce a taint checking based verification approach that works specifically for our low-latency approach and allows us to verify large circuits like our low-latency AES S-box design in reasonable time.

Category / Keywords: implementation / masking, low latency, AES, hardware security, threshold implementations, domain-oriented masking

Original Publication (in the same form): IACR-CHES-2018

Date: received 19 Dec 2017, last revised 9 Apr 2018

Contact author: hannes gross at iaik tugraz at

Available format(s): PDF | BibTeX Citation

Version: 20180409:065628 (All versions of this report)

Short URL: ia.cr/2017/1223