Paper 2012/362

Achieving Constant Round Leakage-Resilient Zero-Knowledge

Omkant Pandey

Abstract

Recently there has been a huge emphasis on constructing cryptographic protocols that maintain their security guarantees even in the presence of side channel attacks. Such attacks exploit the physical characteristics of a cryptographic device to learn useful information about the internal state of the device. Designing protocols that deliver meaningful security even in the presence of such leakage attacks is a challenging task. The recent work of Garg, Jain, and Sahai formulates a meaningful notion of zero-knowledge in presence of leakage; and provides a construction which satisfies a weaker variant of this notion called (1+e)-leakage-resilient-zero-knowledge, for every constant e>0. In this weaker variant, roughly speaking, if the verifier learns L bits of leakage during the interaction, then the simulator is allowed to access (1+e).L bits of leakage. The round complexity of their protocol is n/e. In this work, we present the first construction of leakage-resilient zero-knowledge satisfying the ideal requirement of e=0. While our focus is on a feasibility result for e=0, our construction also enjoys a constant number of rounds. At the heart of our construction is a new ``public-coin preamble'' which allows the simulator to recover arbitrary information from a (cheating) verifier in a ``straight line.'' We use non-black-box simulation techniques to accomplish this goal.

Metadata
Available format(s)
PDF
Category
Foundations
Publication info
Published elsewhere. Manuscript
Keywords
Zero KnowledgeLeakageInteractive Proofs
Contact author(s)
omkant @ cs utexas edu
History
2013-02-17: revised
2012-06-29: received
See all versions
Short URL
https://ia.cr/2012/362
License
Creative Commons Attribution
CC BY

BibTeX

@misc{cryptoeprint:2012/362,
      author = {Omkant Pandey},
      title = {Achieving Constant Round Leakage-Resilient Zero-Knowledge},
      howpublished = {Cryptology ePrint Archive, Paper 2012/362},
      year = {2012},
      note = {\url{https://eprint.iacr.org/2012/362}},
      url = {https://eprint.iacr.org/2012/362}
}
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