@inproceedings{6528,
abstract = {We construct a verifiable delay function (VDF) by showing how the Rivest-Shamir-Wagner time-lock puzzle can be made publicly verifiable. Concretely, we give a statistically sound public-coin protocol to prove that a tuple (N,x,T,y) satisfies y=x2T (mod N) where the prover doesn’t know the factorization of N and its running time is dominated by solving the puzzle, that is, compute x2T, which is conjectured to require T sequential squarings. To get a VDF we make this protocol non-interactive using the Fiat-Shamir heuristic.The motivation for this work comes from the Chia blockchain design, which uses a VDF as akey ingredient. For typical parameters (T≤2 40, N= 2048), our proofs are of size around 10K B, verification cost around three RSA exponentiations and computing the proof is 8000 times faster than solving the puzzle even without any parallelism.},
author = {Pietrzak, Krzysztof Z},
booktitle = {10th Innovations in Theoretical Computer Science Conference},
isbn = {978-3-95977-095-8},
issn = {1868-8969},
location = {San Diego, CA, United States},
publisher = {Schloss Dagstuhl - Leibniz-Zentrum für Informatik},
title = {{Simple verifiable delay functions}},
doi = {10.4230/LIPICS.ITCS.2019.60},
volume = {124},
year = {2019},
}