Paper 2020/1026
Simple and Efficient FE for Quadratic Functions
Junqing Gong and Haifeng Qian
Abstract
This paper presents the first functional encryption schemes for quadratic functions (or degree-2 polynomials) achieving simulation-based security in the semi-adaptive model with constant-size secret key. The unique prior construction with the same security guarantee by Gay [PKC 20] has secret keys of size linear in the message size. They also enjoy shorter ciphertexts: - our first scheme is based on bilateral DLIN (decisional linear) assumption as Gay's scheme and the ciphertext is 15% shorter; - our second scheme based on SXDH assumption and bilateral DLIN assumption is more efficient; it has 67% shorter ciphertext than previous SXDH-based scheme with selective indistinguishability security by Baltico et al. [CRYPTO 17]; the efficiency is comparable to their second scheme in the generic group model. Technically, we roughly combine Wee's ``secret-key-to-public-key'' compiler [TCC 17] with Gay's paradigm [PKC 20]. We avoid (partial) function-hiding inner-product functional encryption used in Gay's work and make our schemes conceptually simpler.
Metadata
- Available format(s)
-
PDF
- Category
- Public-key cryptography
- Publication info
- Preprint. MINOR revision.
- Contact author(s)
-
jqgong @ sei ecnu edu cn
hfqian @ cs ecnu edu cn - History
- 2020-08-27: received
- Short URL
- https://ia.cr/2020/1026
- License
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CC BY
BibTeX
@misc{cryptoeprint:2020/1026,
author = {Junqing Gong and Haifeng Qian},
title = {Simple and Efficient FE for Quadratic Functions},
howpublished = {Cryptology ePrint Archive, Paper 2020/1026},
year = {2020},
note = {\url{https://eprint.iacr.org/2020/1026}},
url = {https://eprint.iacr.org/2020/1026}
}
