## CryptoDB

### Paper: Universally Composable Commitments

Authors: Ran Canetti Marc Fischlin URL: http://eprint.iacr.org/2001/055 Search ePrint Search Google We propose a new security measure for commitment protocols, called /universally composable/ (UC) Commitment. The measure guarantees that commitment protocols behave like an "ideal commitment service," even when concurrently composed with an arbitrary set of protocols. This is a strong guarantee: it implies that security is maintained even when an unbounded number of copies of the scheme are running concurrently, it implies non-malleability (not only with respect to other copies of the same protocol but even with respect to other protocols), it provides resilience to selective decommitment, and more. Unfortunately two-party UC commitment protocols do not exist in the plain model. However, we construct two-party UC commitment protocols, based on general complexity assumptions, in the /common reference string model/ where all parties have access to a common string taken from a predetermined distribution. The protocols are non-interactive, in the sense that both the commitment and the opening phases consist of a single message from the committer to the receiver.
##### BibTeX
@misc{eprint-2001-11467,
title={Universally Composable Commitments},
booktitle={IACR Eprint archive},
keywords={foundations / commitment schemes, concurrent composition,},
url={http://eprint.iacr.org/2001/055},
note={extended abstract appears in Proceedings of Crypto 2001 marc@mi.informatik.uni-frankfurt.de 11513 received 10 Jul 2001},
author={Ran Canetti and Marc Fischlin},
year=2001
}