EAGER: Communication without Repudiation

University Of Texas At Austin, Austin TX

Investigators

Abstract

A "non-repudiation protocol" between two parties S and R over the Internet defends against party S sending a message to party R then later repudiating that it has sent the message and against party R receiving a message from party S then later repudiating that it has received the message. The main goal of this proposal is to design non-repudiation protocols that do not involve a third party that needs to be blindly trusted by both S and R. Non-repudiation protocols that do not involve trusted parties are essential for realizing secure certified email services over the Internet. This project attempts to answer three fundamental questions concerning the design of non-repudiation protocols. The first question is "Can one design non-repudiation protocols that do not involve a trusted third party?" The second question is "What is a least invasive trusted party that needs to be involved in a non-repudiation protocol?" The third question is "Can one plan a certified email service based on a non-repudiation protocol that involves a least invasive trusted party?" To answer these questions, the PI proposes to design non-repudiation protocols that do not involve trusted parties or that involve the least invasive trusted parties. In addition, the proposed protocol will tolerate the loss and corruption of sent messages and will not require the participating parties to have tightly synchronized clocks. The project is also proceeding towards implementing a certified email service that is based on a non-repudiation protocol that involves a least invasive trusted party.