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Title: Flexible Password-Based Encryption: Securing Cloud Storage and Provably Resisting Partitioning-Oracle Attacks
We introduce flexible password-based encryption (FPBE), an extension of traditional password-based encryption designed to meet the operational and security needs of contemporary applications like end-to-end secure cloud storage. Operationally, FPBE supports nonces, associated data and salt reuse. Security-wise, it strengthens the usual privacy requirement, and, most importantly, adds an authenticity requirement, crucial because end-to-end security must protect against a malicious server. We give an FPBE scheme called DtE that is not only proven secure, but with good bounds. The challenge, with regard to the latter, is in circumventing partitioning-oracle attacks, which is done by leveraging key-robust (also called key-committing) encryption and a notion of authenticity with corruptions. DtE can be instantiated to yield an efficient and practical FPBE scheme for the target applications.  more » « less
Award ID(s):
2154272
PAR ID:
10411590
Author(s) / Creator(s):
;
Editor(s):
Rosulek, Mike
Date Published:
Journal Name:
Topics in Cryptology - CT-RSA 2023 - Cryptographers' Track at the RSA Conference 2023
Volume:
13871 LNCS
Page Range / eLocation ID:
594-621
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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