Round Optimal Fully Secure Distributed Key Generation

Jonathan Katz

Paper 2023/1094

Round Optimal Fully Secure Distributed Key Generation

Jonathan Katz

, Dfns

Abstract

Protocols for distributed (threshold) key generation (DKG) in the discrete-logarithm setting have received a tremendous amount of attention in the past few years. Several synchronous DKG protocols have been proposed, but most such protocols are not fully secure: they either allow corrupted parties to bias the key, or are not robust and allow malicious parties to prevent successful generation of a key. We explore the round complexity of fully secure DKG in the honest-majority setting where it is feasible. We show the impossibility of one-round, unbiased DKG protocols (even satisfying weaker notions of security), regardless of any prior setup. On the positive side, we show various round-optimal protocols for fully secure DKG offering tradeoffs in terms of their efficiency, necessary setup, and required assumptions.

Metadata

Available format(s): PDF
Category: Cryptographic protocols
Publication info: A minor revision of an IACR publication in CRYPTO 2024
Keywords: threshold cryptography key generation
Contact author(s): jkatz2 @ gmail com
History: 2025-03-11: last of 5 revisions; 2023-07-13: received; See all versions
Short URL: https://ia.cr/2023/1094
License: CC BY-NC-ND

BibTeX

@misc{cryptoeprint:2023/1094,
      author = {Jonathan Katz},
      title = {Round Optimal Fully Secure Distributed Key Generation},
      howpublished = {Cryptology {ePrint} Archive, Paper 2023/1094},
      year = {2023},
      url = {https://eprint.iacr.org/2023/1094}
}