Paper 2026/2399 Original: eprint.iacr.org/2026/2399 ↗
A Note on Extractable Witness Encryption in Generic Groups
Abstract
Hair and Sahai have recently proposed a construction of witness encryption for NP satisfying semantic security. In this short note we observe that this recent witness-encryption construction is unconditionally extractable in the generic group model. This yields a construction of extractable witness encryption without assuming subexponential soundness of SNARGs, in contrast to the recent work of Jin (eprint:2026/2063), which requires this assumption. The result in this note, moreover, complements the concurrent work of Chen and Vaikuntanathan (eprint:2026/2346), who show the same construction to be public-coin extractable under a knowledge-style assumption; our argument is unconditional, but in the GGM.
Metadata
- Available format(s)
PDF- Category
- Foundations
- Publication info
- Preprint.
- History
- 2026-10-07: last updated
- 2026-10-07: published
- Short URL
- https://ia.cr/2026/2399
- License
- https://creativecommons.org/licenses/by/4.0/
BibTeX
@misc{cryptoeprint:2026/2399,
author = {Matteo Campanelli},
title = {A Note on Extractable Witness Encryption in Generic Groups},
howpublished = {Cryptology {ePrint} Archive, Paper 2026/2399},
year = {2026},
url = {https://eprint.iacr.org/2026/2399}
}