Paper 2020/773

An Instruction Set Extension to Support Software-Based Masking

Johann Großschädl and Ben Marshall and Dan Page and Thinh Pham and Francesco Regazzoni

Abstract

In both hardware and software, masking can represent an effective means of hardening an implementation against side-channel attacks such as Differential Power Analysis (DPA). Focusing on software, however, the use of masking can present various challenges: specifically, it often 1) requires significant effort to translate any theoretical security properties into practice, and, even then, 2) imposes a significant overhead in terms of efficiency. To address both challenges, this paper explores use of an Instruction Set Extension (ISE) as a means of supporting masking in software-based implementations of symmetric cryptographic algorithms: we design, implement, and evaluate such an ISE using RISC-V as the base architecture.