Cryptology ePrint Archive: Report 2015/704
Indistinguishability Obfuscation: from Approximate to Exact
Nir Bitansky and Vinod Vaikuntanathan
Abstract: We show general transformations from subexponentially-secure approximate indistinguishability obfuscation (IO) where the obfuscated circuit agrees with the original circuit on a $1/2+\epsilon$ fraction of inputs, into exact indistinguishability obfuscation where the
obfuscated circuit and the original circuit agree on all inputs (except for a negligible probability over the coin tosses of the obfuscator). As a step towards our results, which is of independent interest, we also obtain an approximate-to-exact transformation for functional encryption. At the core of our techniques is a method for ``fooling'' the obfuscator into giving us the correct answer, while preserving the indistinguishability-based security. This is achieved based on various types of secure computation protocols that can be obtained from different standard assumptions.
Put together with the recent results of Canetti, Kalai and Paneth (TCC 2015), Pass and Shelat (Eprint 2015), and Mahmoody, Mohammed and Nemathaji (Eprint 2015), we show how to convert indistinguishability obfuscation schemes in various ideal models into exact obfuscation schemes in the plain model.
Category / Keywords: Obfusaction, Functional-Encryption, Secure-Function-Evaluation, Error-Correction
Original Publication (with minor differences): IACR-TCC-2016
Date: received 13 Jul 2015, last revised 23 Nov 2015
Contact author: nirbitan at csail mit edu
Available format(s): PDF | BibTeX Citation
Note: - Added almost exact to exact transformation.
- Added missing details to section 5.
Version: 20151124:022623 (All versions of this report)
Short URL: ia.cr/2015/704
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