INFORMATION-THEORETICALLY SECURE STRONG VERIFIABLE SECRET SHARING

Changlu Lin, Lein Harn, Dingfeng Ye

2009

Abstract

In a (t,n) secret sharing scheme, a mutually trusted dealer divides a secret into n shares in such a way that any t or more than t shares can reconstruct the secret, but fewer than t shares cannot reconstruct the secret. When there is no mutually trusted dealer, a (n, t,n) secret sharing scheme can be used to set up a (t,n) secret sharing because each shareholder also acts as a dealer to decide a master secret jointly and divide each selected secret for others. A verifiable secret sharing (VSS) allows each shareholder to verify that all shares are t-consistent (i.e. every subset of t of the n shares defines the same secret). In this paper, we show that (t,n)-VSS and (n, t,n)-VSS proposed by Pedersen can only ensure that all shares are t-consistent; but shares may not satisfy the security requirements of secret sharing scheme. Then, we introduce a new notion of strong VSS. A strong VSS scheme can ensure that (a) all shares are t-consistent, and (b) all shares satisfy the security requirements of secret sharing scheme. We propose two simple ways to convert Pedersen’s VSS schemes into strong VSS schemes, which are information-theoretically secure. We also prove that our proposed VSS schemes satisfy the strong verifiable property.

Paper Citation

in Harvard Style

Lin C., Harn L. and Ye D. (2009). INFORMATION-THEORETICALLY SECURE STRONG VERIFIABLE SECRET SHARING . In Proceedings of the International Conference on Security and Cryptography - Volume 1: SECRYPT, (ICETE 2009) ISBN 978-989-674-005-4, pages 233-238. DOI: 10.5220/0002222402330238

in Bibtex Style

@conference{secrypt09,
author={Changlu Lin and Lein Harn and Dingfeng Ye},
title={INFORMATION-THEORETICALLY SECURE STRONG VERIFIABLE SECRET SHARING},
booktitle={Proceedings of the International Conference on Security and Cryptography - Volume 1: SECRYPT, (ICETE 2009)},
year={2009},
pages={233-238},
publisher={SciTePress},
organization={INSTICC},
doi={10.5220/0002222402330238},
isbn={978-989-674-005-4},
}

in EndNote Style

TY - CONF
JO - Proceedings of the International Conference on Security and Cryptography - Volume 1: SECRYPT, (ICETE 2009)
TI - INFORMATION-THEORETICALLY SECURE STRONG VERIFIABLE SECRET SHARING
SN - 978-989-674-005-4
AU - Lin C.
AU - Harn L.
AU - Ye D.
PY - 2009
SP - 233
EP - 238
DO - 10.5220/0002222402330238