Paper 2017/638
From Single-Key to Collusion-Resistant Secret-Key Functional Encryption by Leveraging Succinctness
Fuyuki Kitagawa, Ryo Nishimaki, and Keisuke Tanaka
Abstract
We show how to construct secret-key functional encryption (SKFE) supporting unbounded polynomially many functional decryption keys, that is, collusion-resistant SKFE solely from SKFE supporting only one functional decryption key. The underlying single-key SKFE needs to be weakly succinct, that is, the size of its encryption circuit is sub-linear in the size of functions. We show we can transform any quasi-polynomially secure single-key weakly-succinct SKFE into quasi-polynomially secure collusion-resistant one. In addition, if the underlying single-key SKFE is sub-exponentially secure, then so does the resulting scheme in our construction. Some recent results show the power and usefulness of collusion-resistant SKFE. From our result, we see that succinct SKFE is also a powerful and useful primitive. In particular, by combining our result and the result by Kitagawa, Nishimaki, and Tanaka (ePrint 2017), we can obtain indistinguishability obfuscation from sub-exponentially secure weakly succinct SKFE that supports only a single functional decryption key.
Metadata
- Available format(s)
-
PDF
- Category
- Foundations
- Publication info
- A major revision of an IACR publication in EUROCRYPT 2018
- Keywords
- Secret-key functional encryptionCollusion-resistanceSuccinctnessObfuscation
- Contact author(s)
-
kitagaw1 @ is titech ac jp
ryo nishimaki @ gmail com - History
- 2018-02-19: last of 5 revisions
- 2017-07-03: received
- See all versions
- Short URL
- https://ia.cr/2017/638
- License
-
CC BY
BibTeX
@misc{cryptoeprint:2017/638,
author = {Fuyuki Kitagawa and Ryo Nishimaki and Keisuke Tanaka},
title = {From Single-Key to Collusion-Resistant Secret-Key Functional Encryption by Leveraging Succinctness},
howpublished = {Cryptology {ePrint} Archive, Paper 2017/638},
year = {2017},
url = {https://eprint.iacr.org/2017/638}
}
