Bilibili Tech

Jun 28, 2022 · Information Security

Code Branch Avoidance Techniques in SM2 Elliptic Curve Cryptographic Implementations

The article explains how data‑dependent branches in SM2 elliptic‑curve implementations leak secret keys via power, EM, and cache side‑channels, compares point addition and doubling, critiques Montgomery ladder timing leaks, and proposes a branch‑free select‑based scalar multiplication to achieve constant‑time security at some performance cost.