Fully Bideniable Public-Key Encryption

Marcel Šebek

Paper 2013/684

Fully Bideniable Public-Key Encryption

Marcel Šebek

Abstract

Bideniable encryption allows both sender and receiver in a public-key setting to simultaneously claim that a different message of their choice was transmitted, and support this claim by a good-looking encryption and key-generation randomness, respectively. A weaker version with two variants of algorithms is called flexible or multi-distributional deniability, a stronger one-algorithm version is called full deniability. Bendlin et al. (ASIACRYPT 2011) showed that certain kinds of fully-deniable schemes are constructible using corresponding flexible schemes. In this paper, we show that their construction in the bideniable case has a flaw, and we provide a fixed scheme. Our construction relies on a deterministic subset matching algorithm that assigns to each nonempty subset of a finite set its proper subset reduced by exactly one element. Although this algorithm is crucial in our construction, it may also be of independent interest.

Metadata

Available format(s): PDF
Category: Public-key cryptography
Publication info: Preprint. MINOR revision.
Keywords: deniable encryption plausible deniability fully bideniable PKE subset matching
Contact author(s): marcel sebek @ matfyz cz
History: 2013-10-24: received
Short URL: https://ia.cr/2013/684
License: CC BY

BibTeX

@misc{cryptoeprint:2013/684,
      author = {Marcel Šebek},
      title = {Fully Bideniable Public-Key Encryption},
      howpublished = {Cryptology {ePrint} Archive, Paper 2013/684},
      year = {2013},
      url = {https://eprint.iacr.org/2013/684}
}