Paper 2024/355
Adaptively Secure Streaming Functional Encryption
, NTT Research, Zellic, University of California, Los Angeles, University of California, Los AngelesAbstract
This paper presents the first adaptively secure streaming functional encryption (sFE) scheme for P/Poly. sFE extends traditional FE to vast and/or dynamically evolving data sets, enabling incremental encryption of streaming inputs and iterative partial decryption over encrypted prefixes. The proposed sFE scheme is built from indistinguishability obfuscation for P/Poly and injective PRGs. We achieve this result via two core technical contributions which may be of independent interest. First, we introduce a novel "gluing" mechanism to achieve adaptive security by intertwining two schemes, each possessing one aspect of adaptive security. Second, we enhance the powerful Koppula-Lewko-Waters [STOC 2015] framework with a "sliding window" technique, enabling authenticated iterative computation with fresh inputs at each iteration. Prior work by Guan, Korb, and Sahai [CRYPTO 2023] constructed sFE but only under a (semi-adaptive) function-selective security model, requiring all functional keys to be queried before observing any ciphertext. This severe limitation precludes practical scenarios and leaves adaptive security as a crucial open challenge — explicitly highlighted by their work — which we address in this paper.
Metadata
- Available format(s)
-
PDF
- Category
- Public-key cryptography
- Publication info
- A major revision of an IACR publication in TCC 2025
- DOI
- 10.1007/978-3-032-12293-3_11
- Keywords
- Functional EncryptionObfuscationAdaptive Security
- Contact author(s)
-
pratish datta @ ntt-research com
jiaxin @ guan io
alexiskorb @ cs ucla edu
sahai @ cs ucla edu - History
- 2025-12-06: last of 2 revisions
- 2024-02-27: received
- See all versions
- Short URL
- https://ia.cr/2024/355
- License
-
CC BY
BibTeX
@misc{cryptoeprint:2024/355,
author = {Pratish Datta and Jiaxin Guan and Alexis Korb and Amit Sahai},
title = {Adaptively Secure Streaming Functional Encryption},
howpublished = {Cryptology {ePrint} Archive, Paper 2024/355},
year = {2024},
doi = {10.1007/978-3-032-12293-3_11},
url = {https://eprint.iacr.org/2024/355}
}
