Spam Detection Using an Artificial Immune System
rangeva writes "As anti-spam solutions evolve to limit junk email, the senders quickly adapt to make sure their messages are seen. an interesting article describes the application of an artificial immune system model to effectively protect email users from unwanted messages. In particular, it tests a spam immune system against the publicly available SpamAssassin corpus of spam and non-spam. It does so by classifying email messages with the detectors produced by the immune system. The resulting system classifies the messages with accuracy similar to that of other spam filters, but it does so with fewer detectors."
I recently gave up on tweaking filters for myself and a few dozen people whose accounts I administer. I wrote a little script that asks for confirmation from the sender...if the sender confirms, they are added to a whitelist and will go straight through after that. I can also add addresses manually to the whitelist, and will soon be able to have wildcard (domain-wide) approved addresses. I've gotten exactly two spam in 6 weeks...both were confirmed by either a person or an autoresponder. Five years ago I never would have wanted such a blunt system...nowadays it's just the ticket.
Evil is the money of root.
More specifically, it correctly classifies 84% of spam and 98% of non-spam.
The authors used the SpamAssassin corpus. Holden shows that, on the Spamassasin corpus, Bogofilter correctly classifies 90.3% of spam and 99.88% of non-spam. See http://sam.holden.id.au/writings/spam2/
This approach is nowhere near state of the art.
Perhaps a neat way to extend this idea would be to have the filter scan your outgoing mail, too; not to search for spam as such, but to look for changes in behaviour. Then, supposing you emailed sales@igottagetmearolex.com enquiring the price of a Rolex, the filter could modify the spam and ham probabilities of rolex. I suppose it would have to be clever enough to ignore emails sent to abuse@ addresses reporting spam and attaching the spam message, among other things I can't be bothered to think of now, but it's an idea that comes more readily from the immune system metaphor than the pure probability metaphor.
"'I pass the test,' she said. 'I will diminish, and go into the West, and remain Galadriel.'"
- JRR Tolkien.