Identity based email sender authentication for spam mitigation

The elimination of unsolicited bulk emails, also known as spam, is still a largely unsolved problem. Making up for the vast majority of emails transmitted, spam is an annoyance and potential security issue for users, and moreover a superfluous burden to the internet. Despite the maturity of today´s email infrastructure, it is difficult to ensure the authenticity of a sender address for inbound mails. This shortcoming is used by spammers to bypass existing spam protection systems and furthermore poses a security risk to users. Due to this a vast majority of spam emails today are sent from botnets with forged sender addresses. This has attracted researchers over the years to develop email sender authentication mechanism as a promising way to verify identity of the senders. In this paper we introduce iSATS, a new email sender authentication system based on Identity-based public key cryptography. iSATS leverages identity based signature scheme to provide a reliable and easy way to bind the identity of legitimate sender unambiguously to his emails. Unlike the popular existing solutions like SPF and DKIM, it is hard for the spammer to adopt iSATS. Evaluation of the prototype implementation show promising performance with low processing overhead on different computational setups.