Advances in Cryptology – CRYPTO 2008
Volume 5157 of the series Lecture Notes in Computer Science pp 515-535
Efficient Constructions of Composable Commitments and Zero-Knowledge Proofs
- Yevgeniy DodisAffiliated withNew York University
- , Victor ShoupAffiliated withNew York University
- , Shabsi WalfishAffiliated withGoogle
Abstract
Canetti et al. [7] recently proposed a new framework — termed Generalized Universal Composability (GUC) — for properly analyzing concurrent execution of cryptographic protocols in the presence of a global setup, and constructed the first known GUC-secure implementations of commitment (GUCC) and zero-knowledge (GUC ZK), which suffice to implement any two-party or multi-party functionality under several natural and relatively mild setup assumptions. Unfortunately, the feasibility results of [7] used rather inefficient constructions.
In this paper, we dramatically improve the efficiency of (adaptively-secure) GUCC and GUC ZK assuming data erasures are allowed. Namely, using the same minimal setup assumptions as those used by [7], we build
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a direct and efficient constant-round GUC ZK for R from any “dense” Ω-protocol [21] for R. As a corollary, we get a semi-efficient construction from any Σ-protocol for R (without doing the Cook-Levin reduction), and a very efficient GUC ZK for proving knowledge of a discrete log representation.
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the first constant-rate (and constant-round) GUCC scheme.
Additionally, we show how to properly model a random oracle in the GUC framework without losing deniability, which is one of the attractive features of the GUC framework. In particular, by adding the random oracle to the setup assumptions used by [7], we build the first two-round (which we show is optimal), deniable, straight-line extractable and simulatable ZK proof for any NP relation R.
- Title
- Efficient Constructions of Composable Commitments and Zero-Knowledge Proofs
- Book Title
- Advances in Cryptology – CRYPTO 2008
- Book Subtitle
- 28th Annual International Cryptology Conference, Santa Barbara, CA, USA, August 17-21, 2008. Proceedings
- Pages
- pp 515-535
- Copyright
- 2008
- DOI
- 10.1007/978-3-540-85174-5_29
- Print ISBN
- 978-3-540-85173-8
- Online ISBN
- 978-3-540-85174-5
- Series Title
- Lecture Notes in Computer Science
- Series Volume
- 5157
- Series ISSN
- 0302-9743
- Publisher
- Springer Berlin Heidelberg
- Copyright Holder
- Springer-Verlag Berlin Heidelberg
- Additional Links
- Topics
- Industry Sectors
- eBook Packages
- Editors
- Authors
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- Yevgeniy Dodis (1)
- Victor Shoup (1)
- Shabsi Walfish (2)
- Author Affiliations
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- 1. New York University,
- 2. Google,
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