Paper 2013/638
DFA-Based Functional Encryption: Adaptive Security from Dual System Encryption
Somindu C. Ramanna
Abstract
We present an adaptively secure functional encryption (FE) scheme based on deterministic finite automata (DFA). The construction uses composite-order bilinear pairings and is built upon the selectively secure DFA-based FE scheme of Waters (Crypto 2012). The scheme is proven secure using the dual system methodology under static subgroup decision assumptions. A dual system proof requires generating of semi-functional components from the instance. In addition, these components must be shown to be properly distributed in an attacker's view. This can be ensured by imposing a restriction on the automata and strings over which the scheme is built i.e., every symbol can appear at most once in a string and in the set of transition tuples of an automata. First a basic construction with the restrictions is obtained and proved to be adaptively secure. We then show how to extend this basic scheme to a full scheme where the restrictions can be relaxed by placing a bound on the number of occurrences of any symbol in a string and in the set of transitions. With the relaxed restrictions, our system supports functionality defined by a larger class of regular languages.
Metadata
- Available format(s)
-
PDF
- Publication info
- Preprint. MINOR revision.
- Keywords
- functional encryption (FE)deterministic finite automataFE over regular languagesdual system encryption
- Contact author(s)
- somindu_r @ isical ac in
- History
- 2013-10-05: received
- Short URL
- https://ia.cr/2013/638
- License
-
CC BY
BibTeX
@misc{cryptoeprint:2013/638,
author = {Somindu C. Ramanna},
title = {DFA-Based Functional Encryption: Adaptive Security from Dual System Encryption},
howpublished = {Cryptology ePrint Archive, Paper 2013/638},
year = {2013},
note = {\url{https://eprint.iacr.org/2013/638}},
url = {https://eprint.iacr.org/2013/638}
}
