An email spam filtering proxy using secure authentication and micro-bonds

Abstract

The Apuma system described in this thesis was designed and implemented as a novel combination of existing technologies in order to give an email user full control over their incoming email. The innate uncertainty of automatic spam detection creates a tension between the desire to filter 100% of spam, and the need to avoid the loss of legitimate mail. Apuma attempts to solve this problem by combining accept-lists with payment systems and content evaluation. Messages from known senders can be exempted from filtering; combined with intelligent automated management of the accept-list this can eliminate the vast majority of false-positives. Remaining mail can thus be subjected to much more rigorous screening. Finally, first time contact and other special cases can be handled with micro-payments or micro-bonds. Apuma includes a plugin interface that allows any financial, proof-of work, or other desired protocol to be integrated into the Apuma filtering framework.