Paper 2023/864
Compact Selective Opening Security From LWE
, ETH Zurich, ETH Zurich, ETH Zurich, ETH ZurichAbstract
Selective opening (SO) security is a security notion for public-key encryption schemes that captures security against adaptive corruptions of senders. SO security comes in chosen-plaintext (SO-CPA) and chosen-ciphertext (SO-CCA) variants, neither of which is implied by standard security notions like IND-CPA or IND-CCA security. In this paper, we present the first SO-CCA secure encryption scheme that combines the following two properties: (1) it has a constant ciphertext expansion (i.e., ciphertexts are only larger than plaintexts by a constant factor), and (2) its security can be proven from a standard assumption. Previously, the only known SO-CCA secure encryption scheme achieving (1) was built from an ad-hoc assumption in the RSA regime. Our construction builds upon LWE, and in particular on a new and surprisingly simple construction of compact lossy trapdoor functions (LTFs). Our LTF can be converted into an “all-but-many LTF” (or ABM-LTF), which is known to be sufficient to obtain SO-CCA security. Along the way, we fix a technical problem in that previous ABM-LTF-based construction of SO-CCA security.
Metadata
- Available format(s)
-
PDF
- Category
- Public-key cryptography
- Publication info
- A minor revision of an IACR publication in PKC 2024
- Keywords
- selective opening securitylossy trapdoor function
- Contact author(s)
-
hofheinz @ inf ethz ch
kristina hostakova @ inf ethz ch
julia kastner @ inf ethz ch
karen klein @ inf ethz ch
akin uenal @ inf ethz ch - History
- 2024-01-19: revised
- 2023-06-07: received
- See all versions
- Short URL
- https://ia.cr/2023/864
- License
-
CC BY
BibTeX
@misc{cryptoeprint:2023/864,
author = {Dennis Hofheinz and Kristina Hostáková and Julia Kastner and Karen Klein and Akin Ünal},
title = {Compact Selective Opening Security From LWE},
howpublished = {Cryptology ePrint Archive, Paper 2023/864},
year = {2023},
note = {\url{https://eprint.iacr.org/2023/864}},
url = {https://eprint.iacr.org/2023/864}
}
