Leakage-Resilient Tokens with Yao Circuits

Abstract:
Within a broader context of mobile and embedded computing, the design of practical, secure tokens that can store and/or process security-critical information remains an ongoing challenge. One aspect of this challenge is the threat of information leakage through side-channel attacks, which is exacerbated by any resource constraints. Although ad-hoc countermeasures can still be of value, it seems clear that any approach providing robust guarantees is more attractive. As such, we extend previous work on use of Yao circuits via three contributions. First, we demonstrate how a suitable token design can support more flexible functionalities through a process of modularisation; this enables the first implementation of a secure authentication functionality, namely HMAC, supporting arbitrary message lengths. Second, we show how careful analysis can fix the maximum number of traces acquired during a DPA attack, effectively bounding the leakage from the token: for a low enough bound, the token can therefore be secured via conventional countermeasures. Finally, we will show how to integrate memory masking, a conventional countermeasure against leakages from the memory and bus.

Bio:
Dipl.-Ing. Simon Hoerder completed his engineering diploma in IT-security at Ruhr-University Bochum in 2009 and is currently a PhD student at University of Bristol's crypto group. His focus is on processor architectures that combine both efficiency and security, especially against side channel attacks.

Host: Kimmo Järvinen