Date Added: Sep 2011
Certified email is a value-added service for standard email systems, which guarantees the fairness, i.e., the intended recipient gets the mail content if and only if the mail originator receives a non-repudiation receipt showing that the message has been received by the recipient. Most of certified email protocols schemes have more or less weaknesses and/or security flaws. E-mail communication is insecure it can be read and modified as they are passed through the Internet as clear-text. In the worst case, fairness cannot be achieved since one dishonest party can mount some attacks to cheat the honest party such that the latter cannot get the expected items.