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The construction of ambiguous optimistic fair exchange from designated confirmer signature without random oracles

Conference Paper


Abstract


  • Ambiguous Optimistic Fair Exchange (AOFE), introduced by Huang et al. in ASIACRYPT 2008, is an extension of OFE that enhances the fairness of the two communicating parties in the exchange of signatures. The first scheme was proven secure without random oracles while its partial signature contains dozens of group elements. Recently, interactive AOFE was introduced and the construction is more practical, where one partial signature only contains three group elements. It is based on the existence of Designated Confirmer Signature (DCS) with a special property where one is able to sample a confirmer signature efficiently from a signer’s signature space. Nevertheless, we note that there are only a few DCS schemes that have this special property. Security of the interactive AOFE construction relies on the q-Computational and Decisional Hidden Strong Diffie-Hellman assumptions. In this paper, we propose a new construction of interactive AOFE from DCS, where the underlying DCS is standard and does not require any special property. We also propose a new DCS construction. By applying our transformation from DCS to interactive AOFE, we build a concrete interactive AOFE which is secure under more standard number-theoretic assumptions, namely Strong Diffie-Hellman and Decision Linear assumptions, without random oracles. A partial signature of the interactive AOFE contains six group elements, while a full signature contains two only.

UOW Authors


  •   Huang, Qiong (external author)
  •   Wong, Duncan S. (external author)
  •   Susilo, Willy

Publication Date


  • 2012

Citation


  • Huang, Q., Wong, D. S. & Susilo, W. (2012). The construction of ambiguous optimistic fair exchange from designated confirmer signature without random oracles. In M. Fischlin, J. Buchmann & M. Manulis (Eds.), Public Key Cryptography - PKC 2012 15th International Conference on Practice and Theory in Public Key Cryptography Darmstadt, Germany, May 21-23, 2012 Proceedings (pp. 120-137). Germany: Springer.

Scopus Eid


  • 2-s2.0-84861664277

Start Page


  • 120

End Page


  • 137

Place Of Publication


  • Germany

Abstract


  • Ambiguous Optimistic Fair Exchange (AOFE), introduced by Huang et al. in ASIACRYPT 2008, is an extension of OFE that enhances the fairness of the two communicating parties in the exchange of signatures. The first scheme was proven secure without random oracles while its partial signature contains dozens of group elements. Recently, interactive AOFE was introduced and the construction is more practical, where one partial signature only contains three group elements. It is based on the existence of Designated Confirmer Signature (DCS) with a special property where one is able to sample a confirmer signature efficiently from a signer’s signature space. Nevertheless, we note that there are only a few DCS schemes that have this special property. Security of the interactive AOFE construction relies on the q-Computational and Decisional Hidden Strong Diffie-Hellman assumptions. In this paper, we propose a new construction of interactive AOFE from DCS, where the underlying DCS is standard and does not require any special property. We also propose a new DCS construction. By applying our transformation from DCS to interactive AOFE, we build a concrete interactive AOFE which is secure under more standard number-theoretic assumptions, namely Strong Diffie-Hellman and Decision Linear assumptions, without random oracles. A partial signature of the interactive AOFE contains six group elements, while a full signature contains two only.

UOW Authors


  •   Huang, Qiong (external author)
  •   Wong, Duncan S. (external author)
  •   Susilo, Willy

Publication Date


  • 2012

Citation


  • Huang, Q., Wong, D. S. & Susilo, W. (2012). The construction of ambiguous optimistic fair exchange from designated confirmer signature without random oracles. In M. Fischlin, J. Buchmann & M. Manulis (Eds.), Public Key Cryptography - PKC 2012 15th International Conference on Practice and Theory in Public Key Cryptography Darmstadt, Germany, May 21-23, 2012 Proceedings (pp. 120-137). Germany: Springer.

Scopus Eid


  • 2-s2.0-84861664277

Start Page


  • 120

End Page


  • 137

Place Of Publication


  • Germany