Cryptology ePrint Archive: Report 2015/854

Efficient Fuzzy Extraction of PUF-Induced Secrets: Theory and Applications

Jeroen Delvaux and Dawu Gu and Ingrid Verbauwhede and Matthias Hiller and Meng-Day (Mandel) Yu

Abstract: The device-unique response of a physically unclonable function (PUF) can serve as the root of trust in an embedded cryptographic system. Fuzzy extractors transform this noisy non-uniformly distributed secret into a stable high-entropy key. The overall efficiency thereof, typically depending on error-correction with a binary [n,k,d] block code, is determined by the universal and well-known (n-k) bound on the min-entropy loss. We derive new considerably tighter bounds for PUF-induced distributions that suffer from, e.g., bias or spatial correlations. The bounds are easy-to-evaluate and apply to large non-trivial codes, e.g., BCH and Reed-Muller codes. Apart from an inherent reduction in implementation footprint, the newly developed theory also facilitates the analysis of state-of-the-art error-correction methods for PUFs. As such, we debunk the reusability claim of the reverse fuzzy extractor. Moreover, we provide proper quantitative motivation for debiasing schemes, as this was missing in the original proposals.

Category / Keywords: fuzzy extractor, secure sketch, min-entropy, physically unclonable functions, coding theory

Original Publication (with major differences): IACR-CHES-2016

Date: received 3 Sep 2015, last revised 14 Jun 2016

Contact author: jeroen delvaux at esat kuleuven be

Available format(s): PDF | BibTeX Citation

Note: This manuscript comprehends an extended version of our CHES 2016 work.

Version: 20160614:110106 (All versions of this report)

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