Paper 2015/993

Bi-Deniable Inner Product Encryption from LWE

Daniel Apon, Xiong Fan, and Feng-Hao Liu

Abstract

Deniable encryption (Canetti et al. CRYPTO '97) is an intriguing primitive that provides a security guarantee against not only eavesdropping attacks as required by semantic security, but also stronger coercion attacks performed after the fact. The concept of deniability has later demonstrated useful and powerful in many other contexts, such as leakage resilience, adaptive security of protocols, and security against selective opening attacks. Despite its conceptual usefulness, our understanding of how to construct deniable primitives under standard assumptions is restricted. In particular, from standard assumptions such as Learning with Errors (LWE), we have only multi-distributional or non-negligible advantage deniable encryption schemes, whereas with the much stronger assumption of indistinguishable obfuscation, we can obtain at least fully-secure sender-deniable PKE and computation. How to achieve deniability for other more advanced encryption schemes under standard assumptions remains an interesting open question. In this work, we construct a bi-deniable inner product encryption (IPE) in the multi-distributional model without relying on obfuscation as a black box. Our techniques involve new ways of manipulating Gaussian noise, and lead to a significantly tighter analysis of noise growth in Dual Regev type encryption schemes. We hope these ideas can give insight into achieving deniability and related properties for further, advanced cryptographic constructions under standard assumptions.

Note: Cleaned up various typos

Metadata
Available format(s)
PDF
Category
Public-key cryptography
Publication info
Preprint. MINOR revision.
Keywords
lattice-based cryptographyinner product encryptionbi-deniability
Contact author(s)
dapon @ cs umd edu
History
2015-11-01: last of 2 revisions
2015-10-13: received
See all versions
Short URL
https://ia.cr/2015/993
License
Creative Commons Attribution
CC BY

BibTeX

@misc{cryptoeprint:2015/993,
      author = {Daniel Apon and Xiong Fan and Feng-Hao Liu},
      title = {Bi-Deniable Inner Product Encryption from LWE},
      howpublished = {Cryptology ePrint Archive, Paper 2015/993},
      year = {2015},
      note = {\url{https://eprint.iacr.org/2015/993}},
      url = {https://eprint.iacr.org/2015/993}
}
Note: In order to protect the privacy of readers, eprint.iacr.org does not use cookies or embedded third party content.