Paper 2023/1024

Timed Secret Sharing

Alireza Kavousi, University College London
Aydin Abadi, Newcastle University
Philipp Jovanovic, University College London
Abstract

This paper introduces the notion of timed secret sharing (TSS), which establishes lower and upper time bounds for secret reconstruction in a threshold secret sharing scheme. Such time bounds are particularly useful in scenarios where an early or late reconstruction of a secret matters. We propose several new constructions that offer different security properties and show how they can be instantiated efficiently using novel techniques. We highlight how our ideas can be used to break the public goods game, which is an issue inherent to threshold secret sharing-based systems, without relying on incentive mechanism. We achieve this through an upper time bound that can be implemented either via short-lived proofs, or the gradual release of additional shares, establishing a trade-off between time and fault tolerance. The latter independently provides robustness in the event of dropout by some portion of shareholders.

Metadata
Available format(s)
PDF
Category
Cryptographic protocols
Publication info
Published by the IACR in ASIACRYPT 2024
Keywords
Secret sharingtime-based cryptographyverifiable delay functiontime-lock puzzle
Contact author(s)
a kavousi @ cs ucl ac uk
aydin abadi @ newcastle ac uk
p jovanovic @ ucl ac uk
History
2024-11-06: last of 2 revisions
2023-07-02: received
See all versions
Short URL
https://ia.cr/2023/1024
License
Creative Commons Attribution
CC BY

BibTeX

@misc{cryptoeprint:2023/1024,
      author = {Alireza Kavousi and Aydin Abadi and Philipp Jovanovic},
      title = {Timed Secret Sharing},
      howpublished = {Cryptology {ePrint} Archive, Paper 2023/1024},
      year = {2023},
      url = {https://eprint.iacr.org/2023/1024}
}
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