Paper 2019/635 Original: eprint.iacr.org/2019/635 ↗
Homomorphic Time-Lock Puzzles and Applications
Abstract
Time-lock puzzles allow one to encrypt messages for the future, by efficiently generating a puzzle with a solution $s$ that remains hidden until time $T$ has elapsed. The solution is required to be concealed from the eyes of any algorithm running in (parallel) time less than $T$. We put forth the concept of \emph{homomorphic time-lock puzzles}, where one can evaluate functions over puzzles without solving them, i.e., one can manipulate a set of puzzles with solutions $(s_1, \dots, s_n)$ to obtain a puzzle that solves to $f(s_1, \ldots, s_n)$, for any function $f$. We propose candidate constructions under concrete cryptographic assumptions for different classes of functions. Then we show how homomorphic time-lock puzzles overcome the limitations of classical time-lock puzzles by proposing new protocols for applications of interest, such as e-voting, multi-party coin flipping, and fair contract signing.
Metadata
- Available format(s)
PDF- Category
- Public-key cryptography
- Publication info
- Preprint.
- History
- 2019-06-03: last updated
- 2019-06-03: published
- Short URL
- https://ia.cr/2019/635
- License
- https://creativecommons.org/licenses/by/4.0/
BibTeX
@misc{cryptoeprint:2019/635,
author = {Giulio Malavolta and Sri Aravinda Krishnan Thyagarajan},
title = {Homomorphic Time-Lock Puzzles and Applications},
howpublished = {Cryptology {ePrint} Archive, Paper 2019/635},
year = {2019},
url = {https://eprint.iacr.org/2019/635}
}