Paper 2000/019
Threshold Cryptography Secure Against the Adaptive Adversary, Concurrently
Anna Lysyanskaya
Abstract
A threshold cryptosystem or signature scheme is a system with $n$ participants where an honest majority can successfully decrypt a message or issue a signature, but where the security and functionality properties of the system are retained even as the adversary corrupts up to $t$ players. We present the novel technique of a committed proof, which is a new general tool that enables security of threshold cryptosystems in the presence of the adaptive adversary. We also put forward a new measure of security for threshold schemes secure in the adaptive adversary model: security under concurrent composition. Using committed proofs, we construct concurrently and adaptively secure threshold protocols for a variety of cryptographic applications. In particular, based on the recent scheme by Cramer-Shoup, we construct adaptively secure threshold cryptosystems secure against adaptive chosen ciphertext attack under the DDH intractability assumption.
Metadata
- Available format(s)
- PS
- Category
- Cryptographic protocols
- Publication info
- Published elsewhere. Part of this paper will appear in Eurocrypt2000
- Keywords
- threshold cryptographyadaptive adversary
- Contact author(s)
- anna @ theory lcs mit edu
- History
- 2000-05-13: received
- Short URL
- https://ia.cr/2000/019
- License
-
CC BY
BibTeX
@misc{cryptoeprint:2000/019,
author = {Anna Lysyanskaya},
title = {Threshold Cryptography Secure Against the Adaptive Adversary, Concurrently},
howpublished = {Cryptology {ePrint} Archive, Paper 2000/019},
year = {2000},
url = {https://eprint.iacr.org/2000/019}
}
