Paper 2007/376
An Efficient Range-Bounded Commitment Scheme
Zhengjun Cao
Abstract
Checking whether a committed integer lies in a specific interval has many cryptographic applications. In Eurocrypt'98, Chan et al. proposed an instantiation (CFT for short). Based on CFT, Boudot presented an efficient range-bounded commitment scheme in Eurocrypt'2000. Both CFT proof and Boudot proof are based on the encryption $E(x, r)=g^xh^r\ \mbox{mod}\ n$, where $n$ is an RSA modulus whose factorization is \textit{unknown} by the prover. They did not use a single base as usual. Thus an increase in cost occurs. In this paper we show that it suffices to adopt a single base. The cost of the improved Boudot proof is about half of that of the original scheme. Moreover, the key restriction in the original scheme, i.e., both the discrete logarithm of $g$ in base $h$ and the discrete logarithm of $h$ in base $g$ are unknown by the prover, which is a potential menace to the Boudot proof, is definitely removed.
Metadata
- Available format(s)
-
PDF
- Category
- Cryptographic protocols
- Publication info
- Published elsewhere. Unknown where it was published
- Keywords
- range-bounded commitmentknowledge of a discrete logarithmzero-knowledge proof
- Contact author(s)
- caozhj @ shu edu cn
- History
- 2007-09-21: received
- Short URL
- https://ia.cr/2007/376
- License
-
CC BY
BibTeX
@misc{cryptoeprint:2007/376,
author = {Zhengjun Cao},
title = {An Efficient Range-Bounded Commitment Scheme},
howpublished = {Cryptology ePrint Archive, Paper 2007/376},
year = {2007},
note = {\url{https://eprint.iacr.org/2007/376}},
url = {https://eprint.iacr.org/2007/376}
}
