Channels: Avoiding unwanted electronic mail

Robert J. Hall
AT&T Labs Research
600 Mountain Ave
Murray Hill, NJ 07974

The full paper is available here


Receiving unwanted communications ranges from mere nuisance (junk mail) through annoyance (telemarketing) to actually endangering the usefulness of the medium (junk fax, obscene or harassing telephone calls). The usefulness of electronic mail is seriously threatened by the exploding commercialization of the Internet, because it is easy to collect and maintain address lists and cheap to mass-distribute messages. This paper describes a novel mechanism, electronic mail channels, that enables users to control who can send them messages, allowing preferential levels of access. The key idea is to give each user the capability of having arbitrarily many structured user names, each of which contains encoded within it a cryptographically unguessable pseudorandom security string. This paper also describes the implementation of a personal channel agent that makes channelized email as easy to use as ordinary email and facilitates administration operations, such as secure remote channel switching.