Publication Type
Conference Proceeding Article
Version
publishedVersion
Publication Date
4-2008
Abstract
Optimistic fair exchange is a kind of protocols to solve the problem of fair exchange between two parties. Almost all the previous work on this topic are provably secure only in the random oracle model. In PKC 2007, Dodis et al. considered optimistic fair exchange in a multi-user setting, and showed that the security of an optimistic fair exchange in a single-user setting may no longer be secure in a multi-user setting. Besides, they also proposed one and reviewed several previous construction paradigms and showed that they are secure in the multi-user setting. However, their proofs are either in the random oracle model, or involving a complex and very inefficient NP-reduction. Furthermore, they only considered schemes in the certified-key model in which each user has to show his knowledge of the private key corresponding to his public key.In this paper, we make the following contributions. First, we consider a relaxed model called chosen-key model in the context of optimistic fair exchange, in which the adversary can arbitrarily choose public keys without showing the knowledge of the private keys. We separate the security of optimistic fair exchange in the chosen-key model from the certified-key model by giving a concrete counterexample. Second, we strengthen the previous static security model in the multi-user setting to a more practical one which allows an adversary to choose a key adaptively. Third, we propose an efficient and generic optimistic fair exchange scheme in the multi-user setting and chosen-key model. The security of our construction is proven without random oracles. We also propose some efficient instantiations.
Keywords
Signature Scheme, Ring Signature, Random Oracle, Random Oracle Model, Cryptology ePrint Archive
Discipline
Information Security
Research Areas
Information Systems and Management
Publication
Proceedings of the Cryptographers’ Track at the RSA Conference 2008, San Francisco, April 8-11
First Page
106
Last Page
120
ISBN
9783540792628
Identifier
10.1007/978-3-540-79263-5_7
Publisher
Springer Verlag
City or Country
San Francisco
Citation
HUANG, Qiong; YANG, Guomin; WONG, Duncan S.; and SUSILO, Willy.
Efficient optimistic fair exchange secure in the multi-user setting and chosen-key model without random oracles. (2008). Proceedings of the Cryptographers’ Track at the RSA Conference 2008, San Francisco, April 8-11. 106-120.
Available at: https://ink.library.smu.edu.sg/sis_research/7382
Creative Commons License
This work is licensed under a Creative Commons Attribution-NonCommercial-No Derivative Works 4.0 International License.
Additional URL
http://doi.org/10.1007/978-3-540-79263-5_7