Publication Type

Conference Proceeding Article

Version

publishedVersion

Publication Date

12-2008

Abstract

Optimistic fair exchange (OFE) is a protocol for solving the problem of exchanging items or services in a fair manner between two parties, a signer and a verifier, with the help of an arbitrator which is called in only when a dispute happens between the two parties. In almost all the previous work on OFE, after obtaining a partial signature from the signer, the verifier can present it to others and show that the signer has indeed committed itself to something corresponding to the partial signature even prior to the completion of the transaction. In some scenarios, this capability given to the verifier may be harmful to the signer. In this paper, we propose the notion of ambiguous optimistic fair exchange (A-OFE), which is an OFE but also requires that the verifier cannot convince anybody about the authorship of a partial signature generated by the signer. We present a formal security model for A-OFE in the multi-user setting and chosen-key model. We also propose an efficient construction with security proven without relying on the random oracle assumption.

Discipline

Information Security

Research Areas

Information Systems and Management

Publication

Proceedings of the 14th International Conference on the Theory and Application of Cryptology and Information Security, Melbourne, Australia, 2008 December 7-11

First Page

74

Last Page

89

ISBN

9783540892540

Identifier

10.1007/978-3-540-89255-7_6

Publisher

Springer Verlag

City or Country

Melbourne, Australia

Additional URL

http://doi.org/10.1007/978-3-540-89255-7_6

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