Paper 2022/1371
On the Security of KOS
Abstract
We study the security of the random oblivious transfer extension protocol of Keller, Orsini, and Scholl (CRYPTO '15), whose security proof was recently invalidated by Roy (CRYPTO '22). We show that KOS is asymptotically secure. Our proof involves a subtle analysis of the protocol's "correlation check", and introduces several new techniques. We also study the protocol's concrete security. We establish concrete security for security parameter values on the order of 5,000. We present evidence that a stronger result than ours—if possible—is likely to require radically new ideas.
Note: Further refinements and improvements to the proofs and to the theoretical framework.
Metadata
- Available format(s)
-
PDF
- Category
- Cryptographic protocols
- Publication info
- Preprint.
- Contact author(s)
- benediamond @ gmail com
- History
- 2023-09-13: last of 4 revisions
- 2022-10-12: received
- See all versions
- Short URL
- https://ia.cr/2022/1371
- License
-
CC BY
BibTeX
@misc{cryptoeprint:2022/1371,
author = {Benjamin E. Diamond},
title = {On the Security of KOS},
howpublished = {Cryptology ePrint Archive, Paper 2022/1371},
year = {2022},
note = {\url{https://eprint.iacr.org/2022/1371}},
url = {https://eprint.iacr.org/2022/1371}
}
