Paper 2020/951
Amplifying the Security of Functional Encryption, Unconditionally
Aayush Jain, Alexis Korb, Nathan Manohar, and Amit Sahai
Abstract
Security amplification is a fundamental problem in cryptography. In this work, we study security amplification for functional encryption (FE). We show two main results: 1) For any constant epsilon in (0,1), we can amplify any FE scheme for P/poly which is epsilon-secure against all polynomial sized adversaries to a fully secure FE scheme for P/poly, unconditionally. 2) For any constant epsilon in (0,1), we can amplify any FE scheme for P/poly which is epsilon-secure against subexponential sized adversaries to a fully subexponentially secure FE scheme for P/poly, unconditionally. Furthermore, both of our amplification results preserve compactness of the underlying FE scheme. Previously, amplification results for FE were only known assuming subexponentially secure LWE. Along the way, we introduce a new form of homomorphic secret sharing called set homomorphic secret sharing that may be of independent interest. Additionally, we introduce a new technique, which allows one to argue security amplification of nested primitives, and prove a general theorem that can be used to analyze the security amplification of parallel repetitions.
Metadata
- Available format(s)
-
PDF
- Category
- Foundations
- Publication info
- A major revision of an IACR publication in CRYPTO 2020
- Keywords
- Functional encryptionsecurity amplification
- Contact author(s)
-
aayushjain @ cs ucla edu
alexiskorb @ cs ucla edu
nmanohar @ cs ucla edu
sahai @ cs ucla edu - History
- 2020-08-11: received
- Short URL
- https://ia.cr/2020/951
- License
-
CC BY
BibTeX
@misc{cryptoeprint:2020/951,
author = {Aayush Jain and Alexis Korb and Nathan Manohar and Amit Sahai},
title = {Amplifying the Security of Functional Encryption, Unconditionally},
howpublished = {Cryptology {ePrint} Archive, Paper 2020/951},
year = {2020},
url = {https://eprint.iacr.org/2020/951}
}