Fair certified e-mail delivery
Aleksandra Nenadić, Ning Zhang, Stephen Barton · 2004
Communication by e-mail has become a vital part of everyday business and has replaced most of the conventional ways of communicating. Important business correspondence may require certified e-mail delivery, analogous to that provided by conventional mail service. This paper presents a novel certified e-mail delivery protocol that provides non-repudiation of origin and non-repudiation of receipt security services to protect communicating parties from each other's false denials that the e-mail has been sent and received. The protocol provides strong fairness to ensure that the recipient receives the e-mail if and only if the sender receives the receipt. The protocol makes use of an off-line and transparent trusted third party only in exceptional circumstances, i.e. when the communicating parties fail to complete the e-mail for receipt exchange due to a network failure or a party's misbehaviour. Considerations have been taken in the protocol design to reduce the use of expensive cryptographic operations for better efficiency and cost-effectiveness.