Paper 2018/576
Simpler Constructions of Asymmetric Primitives from Obfuscation
Pooya Farshim, Georg Fuchsbauer, and Alain Passelègue
Abstract
We revisit constructions of asymmetric primitives from obfuscation and give simpler alternatives. We consider public-key encryption, (hierarchical) identity-based encryption ((H)IBE), and predicate encryption. Obfuscation has already been shown to imply PKE by Sahai and Waters (STOC'14) and full-fledged functional encryption by Garg et al. (FOCS'13). We simplify all these constructions and reduce the necessary assumptions on the class of circuits that the obfuscator needs to support. Our PKE scheme relies on just a PRG and does not need any puncturing. Our IBE and bounded HIBE schemes convert natural key-delegation mechanisms from (recursive) applications of puncturable PRFs to IBE and HIBE schemes. Our most technical contribution is an unbounded HIBE, which uses (public-coin) differing-inputs obfuscation for circuits and whose proof relies on a recent pebbling-based hybrid argument by Fuchsbauer et al. (ASIACRYPT'14). All our constructions are anonymous, support arbitrary inputs, and have compact keys and ciphertexts.
Metadata
- Available format(s)
-
PDF
- Category
- Foundations
- Publication info
- Preprint. MINOR revision.
- Keywords
- obfuscationpublic-key encryptionidentity-based encryptionhierarchical IBEpredicate encryptionpuncturable PRFpebbling.
- Contact author(s)
- pooya farshim @ gmail com
- History
- 2018-06-06: revised
- 2018-06-06: received
- See all versions
- Short URL
- https://ia.cr/2018/576
- License
-
CC BY
BibTeX
@misc{cryptoeprint:2018/576,
author = {Pooya Farshim and Georg Fuchsbauer and Alain Passelègue},
title = {Simpler Constructions of Asymmetric Primitives from Obfuscation},
howpublished = {Cryptology {ePrint} Archive, Paper 2018/576},
year = {2018},
url = {https://eprint.iacr.org/2018/576}
}
