Paper 2025/443
Homomorphic Signature-based Witness Encryption and Applications
Abstract
Practical signature-based witness encryption (SWE) schemes recently emerged as a viable alternative to instantiate timed-release cryptography in the honest majority setting. In particular, assuming threshold trust in a set of parties that release signatures at a specified time, one can ``encrypt to the future'' using an SWE scheme. Applications of SWE schemes include voting, auctions, distributed randomness beacons, and more. However, the lack of homomorphism in existing SWE schemes reduces efficiency and hinders deployment. In this work, we introduce the notion of homomorphic SWE (HSWE) to improve the practicality of timed-release encryption schemes. We show one can build HSWE using a pair of encryption and signature schemes where the uniqueness of the signature is required when the encryption scheme relies on injective one-way functions. We then build three HSWE schemes in various settings using BLS, RSA, and Rabin signatures and show how to achieve a privacy-preserving variant that only allows extracting the homomorphically aggregated result while keeping the individual plaintexts confidential
Metadata
- Available format(s)
-
PDF
- Category
- Cryptographic protocols
- Publication info
- Preprint.
- Keywords
- homomorphic encryptionsignature-based witness encryptiontimed cryptographyidentity-based encryption
- Contact author(s)
-
a kavousi @ cs ucl ac uk
seresistvanandras @ gmail com - History
- 2025-03-10: approved
- 2025-03-07: received
- See all versions
- Short URL
- https://ia.cr/2025/443
- License
-
CC BY
BibTeX
@misc{cryptoeprint:2025/443,
author = {Alireza Kavousi and István András Seres},
title = {Homomorphic Signature-based Witness Encryption and Applications},
howpublished = {Cryptology {ePrint} Archive, Paper 2025/443},
year = {2025},
url = {https://eprint.iacr.org/2025/443}
}
