Paper 2026/2399

A Note on Extractable Witness Encryption in Generic Groups

Matteo Campanelli, Offchain Labs, University of Tartu
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.
Keywords
witness encryption
Contact author(s)
binarywhalesinternaryseas @ gmail com
History
2026-10-08: approved
2026-10-07: received
See all versions
Short URL
https://ia.cr/2026/2399
License
Creative Commons Attribution
CC BY

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}
}
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