Paper 2026/1978
Succinct Two-Round Two-Party Signing from PCFs
, Université Paris Cité, CNRS, IRIF, Paris, France, Université Paris Cité, CNRS, IRIF, Paris, France, Université Paris Cité, CNRS, IRIF, Paris, France, DIENS, École normale supérieure, CNRS, Paris, FranceAbstract
We introduce new two-party threshold signature schemes with strong efficiency and security. The application of our methodology to the two most popular signatures, Schnorr and ECDSA, yields two-round, two-party, stateless and deterministic signing with 4-12 ms of computation on one core of a standard laptop, extremely low communication -- 96 B for Schnorr, and 128 B for ECDSA -- and full concurrent simulatable security. At the heart of our approach is a new pseudorandom correlation function (PCF) for vector-OLE that admits an efficient key generation protocol; we design an end-to-end maliciously-secure and highly parallelizable DKG for this PCF and, using this DKG, we obtain an estimated runtime of 44 s for the (one-time) distributed setup of Schnorr and ECDSA on one core of a standard laptop.
Metadata
- Available format(s)
-
PDF
- Category
- Cryptographic protocols
- Publication info
- A major revision of an IACR publication in CRYPTO 2026
- DOI
- 10.1007/978-3-032-35374-0_4
- Keywords
- pseudorandom correlation functiondsitributed key generationtwo-party signingecdsaschnorr
- Contact author(s)
-
lbraun @ irif fr
couteau @ irif fr
Kelsey Melissaris @ irif fr
mahshid riahinia @ ens fr
elahesadeghi @ utexas edu - History
- 2026-09-13: approved
- 2026-09-11: received
- See all versions
- Short URL
- https://ia.cr/2026/1978
- License
-
CC BY
BibTeX
@misc{cryptoeprint:2026/1978,
author = {Lennart Braun and Geoffroy Couteau and Kelsey Melissaris and Mahshid Riahinia and Elahe Sadeghi},
title = {Succinct Two-Round Two-Party Signing from {PCFs}},
howpublished = {Cryptology {ePrint} Archive, Paper 2026/1978},
year = {2026},
doi = {10.1007/978-3-032-35374-0_4},
url = {https://eprint.iacr.org/2026/1978}
}
