Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

Journal of Xidian University

A fair exchange protocol based on short signature with the off-line semi-trusted third party

Xiangjun Xin, Fagen Li

Published Jan 1, 2007• 0 citations
OpenAlex

Abstract

Based on a short signature scheme and discrete logarithm problem,a new fair exchange protocol with the off-line semi-Trusted Third Party(TTP) is proposed.The off-line semi-TTP intervenes into the protocol in case of trouble,which makes the fair exchange optimistic.The off-line TTP need not be completely trusted,since it can get neither signature exchanged when disputation is solved.Because this protocol is based on short signature,which needs low storage and little communication,it can be used in low-bandwidth communication and low-storage environments.

Related papers

Fair Contract Signing Protocol Based on Short Signature

Luo Wen-jun, Tong Ling, Zufeng Fu +1 more

Based on Zhang's short signature scheme without random oracles and k+1-square roots assumption, a new fair contract signing protocol with the off-line semi-Trusted Third Party is given because the disadvantages of existed fair contract signing protocol. The off-line semi-TTP intervenes into the protocol in cases where one party attempts to cheat or simply crashes to make the fair exchange optimistic. The off-line TTP need not be completely trusted, since the TTP can get neither exchanged signature when dispute is mediated. Because this protocol is based on short signature, which needs low storage and little communication, it can be used in low-bandwidth communication and low-storage environments.

•Jul 1, 2010•1 citation

A fair multi-party exchange protocol with theoff-line trusted third party

Jianzhong Zhang

The difference between the fair exchange protocols and the non-repudiation protocols is proposed. Based on the publicly verifiable secret sharing scheme and group encryption scheme, a new multi-party fair exchagne protocol with an off-line semi-Trusted Third Party(off-STTP) is presented. The off-STTP who need not be completely trusted intervenes into the exchange in case of trouble. That the off-STTP can only decipher a sub-secret key makes sure the confidentiality of exchange data and the true fairness of the barter. The participants can barter with others at their will and the exchange topology is unknown to others including the off-STTP.

Journal of Xidian University•Jan 1, 2004•0 citations

Efficient and practical fair exchange protocols with off-line TTP

Feng Bao, Robert Huijie Deng, Wenbo Mao

We present protocols for fair exchange of electronic data (digital signatures, payment and confidential data) between two parties A and B. Novel properties of the proposed protocols include: 1) offline trusted third party (TTP), i.e., TTP does not take part in the exchange unless one of the parties behaves improperly; 2) only three message exchanges are required in the normal situation; 3) true fair exchange, i.e., either A and B obtain each other's data or no party receives anything useful; no loss can be incurred to a party no matter how maliciously the other party behaves during the exchange. This last property is in contrast to previously proposed protocols with offline TTP ([1] and [21]), where a misbehaving party may get another party's data while refusing to send his document to the other party, and the TTP can provide affidavits attesting to what happened during the exchange. To our knowledge, the protocols presented here are the first exchange protocols which use offline TTP and at the same time guarantee true fair exchange of digital messages. We introduce a novel cryptographic primitive, called the Certificate of Encrypted Message Being a Signature (CEMBS), as the basic building block of the fair exchange protocols. It is used to prove that an encrypted message is a certain party's signature on a public file, without revealing the signature. We also give two examples to show in detail how the certificate can be constructed.

IEEE Symposium on Security and Privacy (S&P)•Nov 27, 2002•295 citations

New Multi-party Fair Exchange Protocol with Off-line Semi-trusted Third Party

DU Hong-zhen, Jianzhong Zhang

At present,the study of multi-party fair exchange protocol is very weak.Aiming at solving the problem,we present a secure and efficient multi-party fair exchange protocol with off-line semi-trusted third party on the basis of Zheng scheme.

Jisuanji yingyong yanjiu•Jan 1, 2006•0 citations

A multiparty fair-exchange protocol

Zhengquan Li

Based on the secret sharing technique,this paper proposes a multi-party fair exchange protocol.The protocol uses an online trusted third party(TTP) in order to help the participants to realize fair exchange.The advantage of a protocol implemented with an online TTP is that the TTP is semi-trusted.Fairness of the proposed protocol is proved in this paper.

Journal of Yangzhou University•Jan 1, 2008•0 citations

New Optimistic Fair Exchange Protocol Based on Short Signature

Yanbin Sun, Lize Gu, Sihan Qing +3 more

In CIS2008, Gao et al. suggested an abuse-free optimistic fair exchange protocol based on the short signature. Their scheme is very efficient in terms of communication. In this paper, we point out that their scheme has two weaknesses. These weaknesses may lead to an unfair situation that Bob may obtain Alice's signature, but Alice can not obtain Bob's signature. In order to overcome these weaknesses, we propose a new secure abuse-free optimistic fair exchange protocol. In the new protocol, both parties can contact the trusted third party and settle the argument before the deadline. Moreover, we give a formal proof of fairness in the strand space model.

IEEE International Conference on Communication Software and Networks•Jan 1, 2010•7 citations
Based on a short signature scheme and discrete logarithm problem,a new fair exchange protocol with the off-line semi-Trusted Third Party(TTP) is proposed.The off-line semi-TTP intervenes into the protocol in case of trouble,which makes the fair exchange optimistic.The off-line TTP need not be completely trusted,since it can get neither signature exchanged when disputation is solved.Because this protocol is based on short signature,which needs low storage and little communication,it can be used in low-bandwidth communication and low-storage environments.
Based on Zhang's short signature scheme without random oracles and k+1-square roots assumption, a new fair contract signing protocol with the off-line semi-Trusted Third Party is given because the disadvantages of existed fair contract signing protocol. The off-line semi-TTP intervenes into the protocol in cases where one party attempts to cheat or simply crashes to make the fair exchange optimistic. The off-line TTP need not be completely trusted, since the TTP can get neither exchanged signature when dispute is mediated. Because this protocol is based on short signature, which needs low storage and little communication, it can be used in low-bandwidth communication and low-storage environments.
The difference between the fair exchange protocols and the non-repudiation protocols is proposed. Based on the publicly verifiable secret sharing scheme and group encryption scheme, a new multi-party fair exchagne protocol with an off-line semi-Trusted Third Party(off-STTP) is presented. The off-STTP who need not be completely trusted intervenes into the exchange in case of trouble. That the off-STTP can only decipher a sub-secret key makes sure the confidentiality of exchange data and the true fairness of the barter. The participants can barter with others at their will and the exchange topology is unknown to others including the off-STTP.
We present protocols for fair exchange of electronic data (digital signatures, payment and confidential data) between two parties A and B. Novel properties of the proposed protocols include: 1) offline trusted third party (TTP), i.e., TTP does not take part in the exchange unless one of the parties behaves improperly; 2) only three message exchanges are required in the normal situation; 3) true fair exchange, i.e., either A and B obtain each other's data or no party receives anything useful; no loss can be incurred to a party no matter how maliciously the other party behaves during the exchange. This last property is in contrast to previously proposed protocols with offline TTP ([1] and [21]), where a misbehaving party may get another party's data while refusing to send his document to the other party, and the TTP can provide affidavits attesting to what happened during the exchange. To our knowledge, the protocols presented here are the first exchange protocols which use offline TTP and at the same time guarantee true fair exchange of digital messages. We introduce a novel cryptographic primitive, called the Certificate of Encrypted Message Being a Signature (CEMBS), as the basic building block of the fair exchange protocols. It is used to prove that an encrypted message is a certain party's signature on a public file, without revealing the signature. We also give two examples to show in detail how the certificate can be constructed.
In CIS2008, Gao et al. suggested an abuse-free optimistic fair exchange protocol based on the short signature. Their scheme is very efficient in terms of communication. In this paper, we point out that their scheme has two weaknesses. These weaknesses may lead to an unfair situation that Bob may obtain Alice's signature, but Alice can not obtain Bob's signature. In order to overcome these weaknesses, we propose a new secure abuse-free optimistic fair exchange protocol. In the new protocol, both parties can contact the trusted third party and settle the argument before the deadline. Moreover, we give a formal proof of fairness in the strand space model.