International Association
for Cryptologic Research

In this paper, we propose that countermeasures against instruction-related timing attack would be vulnerable to single-trace attacks, which are presented at ISPEC 2017 and CHES 2019. The countermeasures use determiner to make operations, which leak timing side-channel information, perform in a constant-time. Since determiner is divided into two groups according to secret credentials, it is possible to recover secret credentials by clustering determiner into two groups.