Certified Side Channels


Cesar Pereida García, Sohaib ul Hassan, Nicola Tuveri, and Iaroslav Gridin, Tampere University; Alejandro Cabrera Aldaya, Tampere University and Universidad Tecnológica de la Habana; Billy Bob Brumley, Tampere University


We demonstrate that the format in which private keys are persisted impacts Side Channel Analysis (SCA) security. Surveying several widely deployed software libraries, we investigate the formats they support, how they parse these keys, and what runtime decisions they make. We uncover a combination of weaknesses and vulnerabilities, in extreme cases inducing completely disjoint multi-precision arithmetic stacks deep within the cryptosystem level for keys that otherwise seem logically equivalent. Exploiting these vulnerabilities, we design and implement key recovery attacks utilizing signals ranging from electromagnetic (EM) emanations, to granular microarchitecture cache timings, to coarse traditional wall clock timings.

Open Access Media

USENIX is committed to Open Access to the research presented at our events. Papers and proceedings are freely available to everyone once the event begins. Any video, audio, and/or slides that are posted after the event are also free and open to everyone. Support USENIX and our commitment to Open Access.

@inproceedings {255234,
author = {Cesar Pereida Garc{\'\i}a and Sohaib ul Hassan and Nicola Tuveri and Iaroslav Gridin and Alejandro Cabrera Aldaya and Billy Bob Brumley},
title = {Certified Side Channels},
booktitle = {29th {USENIX} Security Symposium ({USENIX} Security 20)},
year = {2020},
isbn = {978-1-939133-17-5},
pages = {2021--2038},
url = {https://www.usenix.org/conference/usenixsecurity20/presentation/garcia},
publisher = {{USENIX} Association},
month = aug,

Presentation Video