Paper 2026/2387 Original: eprint.iacr.org/2026/2387 ↗
Quantum Time-Lock Puzzles in the Quantum Random Oracle Model
Abstract
A time-lock puzzle allows a sender to hide a message in a puzzle such that recovering the message requires substantially more sequential computation than the time required to generate the puzzle, even when parallel computation is allowed. Applications of time-lock puzzles include timed-release encryption, sealed-bid auctions, electronic voting, fair contract signing, coin flipping, and Byzantine consensus. However, time-lock puzzles are known to be impossible in the classical random oracle model. To overcome the classical barrier, in this work we consider quantum time-lock puzzles, in which the puzzle itself is a quantum state. Our construction in the quantum random oracle model achieves generation in one oracle round, solving in at most $T$ oracle rounds, and security against polynomial-width quantum adversaries of depth $o(T)$ for every polynomially bounded delay $T$, resolving an open problem posed by Mahmoody, Moran, and Vadhan (2011).
Metadata
- Available format(s)
PDF- Category
- Foundations
- Publication info
- Preprint.
- History
- 2026-10-06: last updated
- 2026-10-06: published
- Short URL
- https://ia.cr/2026/2387
- License
- https://creativecommons.org/licenses/by/4.0/
BibTeX
@misc{cryptoeprint:2026/2387,
author = {Prabhanjan Ananth and Yao-Ting Lin},
title = {Quantum Time-Lock Puzzles in the Quantum Random Oracle Model},
howpublished = {Cryptology {ePrint} Archive, Paper 2026/2387},
year = {2026},
url = {https://eprint.iacr.org/2026/2387}
}