In particular from standard lattice assumptions, i.e. Learning with Errors (LWE), we have only flexibly and non-negligible advantage deniable public-key encryption schemes, whereas with the much stronger assumption of indistinguishable obfuscation, we can obtain at least fully 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 flexibly bi-deniable Attribute-Based Encryption (ABE) scheme for all polynomial-size Branching Programs from LWE. Our techniques involve new ways of manipulating Gaussian noise that may be of independent interest, and lead to a significantly sharper analysis of noise growth in Dual Regev type encryption schemes. We hope these ideas give insight into achieving deniability and related properties for further, advanced cryptographic systems from lattice assumptions.Category / Keywords: public-key cryptography / attribute based encryption, LWE Date: received 2 Jun 2016, last revised 5 Jun 2016 Contact author: xfan at cs cornell edu Available format(s): PDF | BibTeX Citation Version: 20160605:144106 (All versions of this report) Short URL: ia.cr/2016/562 Discussion forum: Show discussion | Start new discussion