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Private Functional Encryption: Indistinguishability-Based Definitions and Constructions from Obfuscation
- Source :
- Progress in Cryptology – INDOCRYPT 2016, Progress in Cryptology – INDOCRYPT 2016, Dec 2016, Kolkata, India. pp.227-247, ⟨10.1007/978-3-319-49890-4_13⟩, Progress in Cryptology – INDOCRYPT 2016 ISBN: 9783319498898, INDOCRYPT
- Publication Year :
- 2016
- Publisher :
- HAL CCSD, 2016.
-
Abstract
- International audience; Private functional encryption guarantees that not only the information in ciphertexts is hidden but also the circuits in decryption tokens are protected. A notable use case of this notion is query privacy in searchable encryption. Prior privacy models in the literature were fine-tuned for specific functionalities (namely, identity-based encryption and inner-product encryption), did not model correlations between ciphertexts and decryption tokens, or fell under strong uninstantiability results. We develop a new indistinguishability-based privacy notion that overcomes these limitations and give constructions supporting different circuit classes and meeting varying degrees of security. Obfuscation is a common building block that these constructions share, albeit the obfuscators necessary for each construction are based on different assumptions. Our feasibility results go beyond previous constructions in a number of ways. In particular, a keyword search scheme that we base on point obfuscators tolerates arbitrary and possibly low-entropy correlations between encrypted data and queried keywords, even under (mildly restricted) adaptive token-extraction queries. Our more elaborate keyword search scheme achieves the strongest notion of privacy that we put forth (with no restrictions), but relies on stronger forms of obfuscation. We also develop a composable and distributionally secure hyperplane membership obfuscator and use it to build an inner-product encryption scheme that achieves an unprecedented level of privacy. This, in particular, positively answers a question left open by Boneh, Raghunathan and Segev (ASIACRYPT 2013) concerning the extension and realization of enhanced security for schemes supporting this functionality.
- Subjects :
- Theoretical computer science
Function privacy
0102 computer and information sciences
02 engineering and technology
Encryption
Computer security
computer.software_genre
01 natural sciences
keyword search
obfuscation
inner-product en- cryption
Multiple encryption
[INFO.INFO-CR]Computer Science [cs]/Cryptography and Security [cs.CR]
0202 electrical engineering, electronic engineering, information engineering
Mathematics
Functional encryption
business.industry
functional encryption
Deterministic encryption
010201 computation theory & mathematics
Probabilistic encryption
56-bit encryption
40-bit encryption
020201 artificial intelligence & image processing
Attribute-based encryption
business
computer
Subjects
Details
- Language :
- English
- ISBN :
- 978-3-319-49889-8
- ISBNs :
- 9783319498898
- Database :
- OpenAIRE
- Journal :
- Progress in Cryptology – INDOCRYPT 2016, Progress in Cryptology – INDOCRYPT 2016, Dec 2016, Kolkata, India. pp.227-247, ⟨10.1007/978-3-319-49890-4_13⟩, Progress in Cryptology – INDOCRYPT 2016 ISBN: 9783319498898, INDOCRYPT
- Accession number :
- edsair.doi.dedup.....e174baccf5e566de313a4764601db322