Cryptology ePrint Archive: Report 2014/899

Side Channel Power Analysis of an AES-256 Bootloader

Colin O'Flynn and Zhizhang Chen

Abstract: Side Channel Attacks (SCA) using power measurements are a known method of breaking cryptographic algorithms such as AES. Published research into attacks on AES frequently target only AES-128, and often target only the core Electronic Code-Book (ECB) algorithm, without discussing surrounding issues such as triggering, along with breaking the initialization vector.

This paper demonstrates a complete attack on a secure bootloader, where the firmware files have been encrypted with AES-256-CBC. A classic Correlation Power Analysis (CPA) attack is performed on AES-256 to recover the complete 32-byte key, and a CPA attack is also used to attempt recovery of the initialization vector (IV).

Category / Keywords: implementation / side channel, power analysis, AES256

Original Publication (in the same form): CCECE 2015 - IEEE Canadian Conference on Electrical and Computer Engineering

Date: received 16 Oct 2014, last revised 19 Mar 2015

Contact author: coflynn at newae com

Available format(s): PDF | BibTeX Citation

Note: Revised to reflect final published version, add copyright notice

Version: 20150319:164112 (All versions of this report)

Short URL: ia.cr/2014/899

Discussion forum: Show discussion | Start new discussion