Private Coin Verifiable Delay Function

Peter Chvojka

Paper 2023/1047

Private Coin Verifiable Delay Function

Peter Chvojka

Abstract

We construct the first tight verifiable delay function (VDF) where the evaluation algorithm only evaluates sequentially the function and hence outputs and empty proof, verification is independent of time parameter $T$ and setup has constant size parameters. Our VDF is based on repeated squaring in hidden order groups, but it requires that coins used to sample a random instance must be kept secret in order to guarantee sequentiality. We denote such a VDF as a private coin verifiable delay function and show that it can be used to obtain multiplicatively homomorphic non-interactive timed commitment with efficient publicly verifiable force decommitment algorithm.

Metadata

Available format(s): PDF
Category: Cryptographic protocols
Publication info: Preprint.
Keywords: verifiable delay function tight verifiable delay function repeated squaring non-interactive timed commitment
Contact author(s): chvojka p @ gmail com
History: 2023-07-05: approved; 2023-07-04: received; See all versions
Short URL: https://ia.cr/2023/1047
License: CC BY

BibTeX

@misc{cryptoeprint:2023/1047,
      author = {Peter Chvojka},
      title = {Private Coin Verifiable Delay Function},
      howpublished = {Cryptology {ePrint} Archive, Paper 2023/1047},
      year = {2023},
      url = {https://eprint.iacr.org/2023/1047}
}