Paper 2018/317
Sliding-Window Correlation Attacks Against Encryption Devices with an Unstable Clock
Dor Fledel and Avishai Wool
Abstract
Power analysis side channel attacks rely on aligned traces. As a counter-measure, devices can use a jittered clock to misalign the power traces. In this paper we suggest a way to overcome this counter-measure, using an old method of integrating samples over time followed by a correlation attack (Sliding Window CPA). We theoretically re-analyze this general method with characteristics of jittered clocks and show that it is stronger than previously believed. We show that integration of samples over a suitably chosen window size actually amplifies the correlation both with and without jitter - as long as multiple leakage points are present within the window. We then validate our analysis on a new data-set of traces measured on a board implementing a jittered clock. Our experiments show that the SW-CPA attack with a well-chosen window size is very successful against a jittered clock counter-measure and significantly outperforms previous suggestions, requiring a much smaller set of traces to correctly identify the correct key.
Note: Asked by eprint
Metadata
- Available format(s)
- Category
- Implementation
- Publication info
- Published elsewhere. Major revision. Proceedings of SAC'18, LNCS 11349, pages 193-215
- Keywords
- Power analysisSW-CPAJittered clocks
- Contact author(s)
- dorfledel @ gmail com
- History
- 2019-02-05: revised
- 2018-04-04: received
- See all versions
- Short URL
- https://ia.cr/2018/317
- License
-
CC BY
BibTeX
@misc{cryptoeprint:2018/317, author = {Dor Fledel and Avishai Wool}, title = {Sliding-Window Correlation Attacks Against Encryption Devices with an Unstable Clock}, howpublished = {Cryptology {ePrint} Archive, Paper 2018/317}, year = {2018}, url = {https://eprint.iacr.org/2018/317} }