Indistinguishability Obfuscation from Functional Encryption for Simple Functions

Prabhanjan Ananth; Abhishek Jain; Amit Sahai

Paper 2015/730

Indistinguishability Obfuscation from Functional Encryption for Simple Functions

Prabhanjan Ananth, Abhishek Jain, and Amit Sahai

Abstract

We show how to construct indistinguishability obfuscation (iO) for circuits from any non-compact functional encryption (FE) scheme with sub-exponential security against unbounded collusions. We accomplish this by giving a generic transformation from any such FE scheme into a compact FE scheme. By composing this with the transformation from sub-exponentially secure compact FE to iO (Ananth and Jain [CRYPTO'15], Bitansky and Vaikuntanathan [FOCS'15]), we obtain our main result. Our result provides a new pathway to iO. We use our technique to identify a simple function family for FE that suffices for our general result. We show that the function family F is complete, where every f in F consists of three evaluations of a Weak PRF followed by finite operations. We believe that this may be useful for realizing iO from weaker assumptions in the future.

Metadata

Available format(s): PDF
Publication info: Preprint. MINOR revision.
Contact author(s): prabhanjan va @ gmail com
History: 2015-10-28: last of 2 revisions; 2015-07-24: received; See all versions
Short URL: https://ia.cr/2015/730
License: CC BY

BibTeX

@misc{cryptoeprint:2015/730,
      author = {Prabhanjan Ananth and Abhishek Jain and Amit Sahai},
      title = {Indistinguishability Obfuscation from Functional Encryption for Simple Functions},
      howpublished = {Cryptology {ePrint} Archive, Paper 2015/730},
      year = {2015},
      url = {https://eprint.iacr.org/2015/730}
}