DeAI Research
Source · arXiv (Cornell University)

SoK: The Constant Time Model

2026Billy Bob Brumley

cid c6822aae6771b753a200d083b8a58b8b7fd068930110508330b0d950d09247b2 · original · open access · via openalex

Title: SoK: The Constant Time Model
Authors: Billy Bob Brumley
Venue: arXiv (Cornell University)
Year: 2026
Canonical: doi:10.48550/arxiv.2606.13000
URL: https://doi.org/10.48550/arxiv.2606.13000
Collector: openalex
OA: true

ABSTRACT
Constant time programming patterns is the primary defense against timing attacks on cryptographic implementations, yet what "constant time" means varies across academia and industry. This work systematizes constant time models and their evolution, identifies a recurring gap between what models protect and what specifications assume, and distills an offensive methodology for discovering timing vulnerabilities that originate outside the cryptographic primitive boundary. Applying this methodology, we locate a specification-level vulnerability related to private key loading, and confirm the leak in both OpenSSL and BoringSSL. Counterintuitively, BoringSSL's per-observation signal is several orders of magnitude stronger than OpenSSL's, despite an explicitly stricter threat model.