Multiparty Nonrepudiation

Abstract

Nonrepudiation is one of the fundamental security issues existing in paper-based and electronic environments. The transacting parties want to seek a fair settlement of disputes, which brings the need nonrepudiation services in their transactions. Nonrepudiation services help the transacting parties to settle possible disputes over whether a particular event or action has been taken place in a transaction. This seminar focuses on multiparty scenarios (applications like e-voting,e-bidding, etc., usually involve several parties) and provides a comprehensive overview. It discusses fundamental issues on nonrepudiation, including the types of nonrepudiation service in the direct and indirect communication model, cryptographic evidence, the roles of Trusted Third Party (TTP), non repudiation phases and requirements. It also describes the general 1-N and N-N multiparty nonrepudiation problems and their solutions. Finally, it discusses advanced solutions for two typical multiparty nonrepudiation applications, namely, multiparty certified email and multiparty contract signing.