Spam Filtering with Cryptographic Ad-hoc E-mail Addresses

This paper presents an ad-hoc e-mail address service system which employs a cryptographic algorithm for the generation of ad-hoc addresses. The addresses are associated with mail filter rules and subscribers' original address undisclosed to public. The presented algorithm enables mail transfer agents to filter incoming mails by extracting filter rules from ad-hoc addresses, and thus requires no database to store filter rules for the addresses. The practical usability of the presented system has been tested to major Internet services which requires e-mail addresses.