Cryptology ePrint Archive: Report 2014/301

How to Avoid Obfuscation Using Witness PRFs

Mark Zhandry

Abstract: Recently, program obfuscation has proven to be an extremely powerful tool and has been used to construct a variety of cryptographic primitives with amazing properties. However, current candidate obfuscators are far from practical and rely on unnatural hardness assumptions about multilinear maps. In this work, we bring several applications of obfuscation closer to practice by showing that a weaker primitive called witness pseudorandom functions (witness PRFs) suces. Applications include multiparty key exchange without trusted setup, polynomially-many hardcore bits for any one-way function, and more. We then show how to instantiate witness PRFs from multilinear maps. Our witness PRFs are simpler and more ecient than current obfuscation candidates, and involve very natural hardness assumptions about the underlying maps.

Category / Keywords: foundations / Multilinear maps, obfuscation

Date: received 29 Apr 2014, last revised 18 May 2014

Contact author: mzhandry at stanford edu

Available format(s): PDF | BibTeX Citation

Note: Mostly typo fixes.

Version: 20140518:201904 (All versions of this report)

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