CryptoDB
Lattice-Based Timed Cryptography
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| Conference: | CRYPTO 2023 |
| Abstract: | Timed cryptography studies primitives that retain their security only for a pre-determined amount of time, such as proofs of sequential work and time-lock puzzles. This feature has proven to be useful in a large number of practical applications, e.g., randomness generation, sealed-bid auctions, or fair multi-party computation. However, the current state of affairs in timed cryptography is unsatisfactory: Virtually all efficient constructions rely on a single sequentiality assumption, namely that repeated squaring in unknown order groups cannot be parallelized. This is a single point of failure in the classical setting and is even false against quantum adversaries. In this work we put forward a new sequentiality assumption, which essentially says that a repeated application of the standard lattice-based hash function cannot be parallelized. We provide concrete evidence of the validity of this assumption and, to substantiate its usefulness, we show how it enables a new proof of sequential work, with a stronger sequentiality guarantee than prior hash-based schemes. |
BibTeX
@inproceedings{crypto-2023-33169,
title={Lattice-Based Timed Cryptography},
publisher={Springer-Verlag},
doi={10.1007/978-3-031-38554-4_25},
author={Russell W. F. Lai and Giulio Malavolta},
year=2023
}