This paper introduces a layered trust management framework to incorporate accountability support into email.
Considering deterrence as important as prevention and protection in countering misuse and abuse of email, the authors aim to improve the accountability in the email system beyond identification and non-repudiability, proposing to use a layered trust management framework to help email receivers eliminate their unwitting trust and provide them with accountability support. This helps systems to deter misuses and address wrongdoings. By describing and analyzing how this trust management facilitates email accountability, the authors also show that it can be used to improve the trustworthiness of the Internet services as a whole. Email used to be the "number one killer application" of the Internet. However, misuse and abuse such as spam, phishing, and malware attacks have plagued the email systems. Full accountability should be an intrinsic condition for trust, and it constitutes the basis of deterrence against email misuse and abuse. (Published Abstract Provided)