Cryptology ePrint Archive: Report 2019/340
Ease of Side-Channel Attacks on AES-192/256 by Targeting Extreme Keys
Antoine Wurcker
Abstract: Concerning the side-channel attacks on Advanced Encryp-
tion Standard, it seems that majority of studies focus on the lowest size:
AES-128. Even when adaptable to higher sizes (AES-192 and AES-256),
lots of state-of-the-art attacks see their complexity substantially raised.
Indeed, it often requires to perform two consecutive dependent attacks.
The first is similar to the one applied on AES-128, but a part of the key
remains unknown and must be retrieved through a second attack directly
dependent on the success of the first.
This configuration may substantially raise the complexity for the at-
tacker, especially if new signal acquisitions with specific input, built using
the first key part recovered, must be performed. Any error/uncertainty
in the first attack raise the key recovery complexity.
Our contribution is to show that this complexity can be lowered to two
independent attacks by the mean of attacking separately first and last
round keys. We show that the information is enough to recover the main
key (or a very small list of candidates) in a negligible exploratory effort.
Category / Keywords: secret-key cryptography / Advanced Encryption Standard, AES, AES-192, AES-256, key recovery, Side-Channel Analysis, SCA
Date: received 30 Mar 2019
Contact author: wurcker01 at gmail com
Available format(s): PDF | BibTeX Citation
Version: 20190403:020245 (All versions of this report)
Short URL: ia.cr/2019/340
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