Toggle Main Menu Toggle Search

Open Access padlockePrints

A Family of Trusted Third Party based Fair-Exchange Protocols

Lookup NU author(s): Dr Paul EzhilchelvanORCiD, Emeritus Professor Santosh Shrivastava



Fair exchange protocols play an important role in application areas such as e-commerce where protocol participants require mutual guarantees that a transaction involving exchange of items has taken place in a specific manner. A protocol is fair if no protocol participant can gain any advantage over an honest participant by misbehaving. In addition, such a protocol is fault tolerant if the protocol can ensure that an honest participant does not suffer any loss of fairness despite any failures of the participant’s node. This report presents a family of fair exchange protocols for two participants which make use of the presence of a trusted third party, under a variety of assumptions concerning participant misbehaviour, message delays and node reliability. The development is systematic, beginning with the strongest set of the assumptions and gradually weakening the assumptions to the weakest set. The resulting protocol family exposes the impact of a given set of assumptions on solving the problem of fair exchange. Specifically, it highlights the relationships that exist between fairness and assumptions on the nature of participant misbehaviour, communication delays and node crashes. The report also shows that the restrictions assumed on a dishonest participant’s misbehaviour can be realized through the use of smartcards and smartcard-based protocols.

Publication metadata

Author(s): Ezhilchelvan PD, Shrivastava S

Publication type: Report

Publication status: Published

Series Title: School of Computing Science Technical Report Series

Year: 2005

Pages: 39

Print publication date: 01/09/2005

Source Publication Date: September 2005

Report Number: 928

Institution: School of Computing Science, University of Newcastle upon Tyne

Place Published: Newcastle upon Tyne