Counting keys in parallel after a side channel attack

Daniel P. Martin*, Jonathan F. O’Connell, Elisabeth Oswald, Martijn Stam

*Corresponding author for this work

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

Side channels provide additional information to skilled adversaries that reduce the effort to determine an unknown key. If sufficient side channel information is available, identification of the secret key can even become trivial. However, if not enough side information is available, some effort is still required to find the key in the key space (which now has reduced entropy). To understand the security implications of side channel attacks it is then crucial to evaluate this remaining effort in a meaningful manner. Quantifying this effort can be done by looking at two key questions: first, how ‘deep’ (at most) is the unknown key in the remaining key space, and second, how ‘expensive’ is it to enumerate keys up to a certain depth? We provide results for these two challenges. Firstly, we show how to construct an extremely efficient algorithm that accurately computes the rank of a (known) key in the list of all keys, when ordered according to some side channel attack scores. Secondly, we show how our approach can be tweaked such that it can be also utilised to enumerate the most likely keys in a parallel fashion. We are hence the first to demonstrate that a smart and parallel key enumeration algorithm exists.

Original languageEnglish
Title of host publicationAdvances in Cryptology – ASIACRYPT 2015 - 21st International Conference on the Theory and Application of Cryptology and Information Security, Proceedings
EditorsTetsu Iwata, Jung Hee Cheon
PublisherSpringer Verlag
Pages313-337
Number of pages25
ISBN (Print)9783662487990
DOIs
Publication statusPublished - 2015
Event21st International Conference on the Theory and Application of Cryptology and Information Security, ASIACRYPT 2015 - Auckland, New Zealand
Duration: 29 Nov 20153 Dec 2015

Publication series

NameLecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)
Volume9453
ISSN (Print)0302-9743
ISSN (Electronic)1611-3349

Conference

Conference21st International Conference on the Theory and Application of Cryptology and Information Security, ASIACRYPT 2015
Country/TerritoryNew Zealand
CityAuckland
Period29/11/153/12/15

Bibliographical note

Funding Information:
We would like to thank Benjamin Sach and Raphael Clifford for there valuable insight and advice during the developement of the algorithm. This work was carried out using the computational facilities of the Advanced Computing Research Centre, University of Bristol - http://www.bris.ac.uk/acrc/. Daniel, Jonathan and Elisabeth have been supported by an EPSRC Leadership Fellowship EP/I005226/1.

Publisher Copyright:
© International Association for Cryptologic Research 2015.

Keywords

  • Key enumeration
  • Key rank
  • Side channels

ASJC Scopus subject areas

  • Theoretical Computer Science
  • General Computer Science

Fingerprint

Dive into the research topics of 'Counting keys in parallel after a side channel attack'. Together they form a unique fingerprint.

Cite this