CryptoDB
Fine-grained Secure Attribute-based Encryption
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| Conference: | CRYPTO 2021 |
| Abstract: | Fine-grained cryptography is constructing cryptosystems in a setting where an adversary’s resource is a-prior bounded and an honest party has less resource than an adversary. Currently, only simple form of encryption schemes, such as secret-key and public-key encryption, are constructed in this setting. In this paper, we enrich the available tools in fine-grained cryptography by proposing the first fine-grained secure attribute-based encryption (ABE) scheme. Our construction is adaptively secure under the widely accepted worst-case assumption, $NC1 \subsetneq \oplus L/poly$, and it is presented in a generic manner using the notion of predicate encodings (Wee, TCC’14). By properly instantiating the underlying encoding, we can obtain different types of ABE schemes, including identity-based encryption. Previously, all of these schemes were unknown in fine-grained cryptography. Our main technical contribution is constructing ABE schemes without using pairing or the Diffie-Hellman assumption. Hence, our results show that, even if one-way functions do not exist, we still have ABE schemes with meaningful security. For more application of our techniques, we construct an efficient (quasi-adaptive) non-interactive zero-knowledge (QA-NIZK) proof system. |
Video from CRYPTO 2021
BibTeX
@inproceedings{crypto-2021-31236,
title={Fine-grained Secure Attribute-based Encryption},
publisher={Springer-Verlag},
doi={10.1007/978-3-030-84259-8_7},
author={Yuyu Wang and Jiaxin Pan and Yu Chen},
year=2021
}