Interesting reading... Thanks, Bill. I did have to go and look up "hapaxes" though:
http://en.wikipedia.org/wiki/Hapax_legomena Andrew 8) > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] On Behalf Of Bill Landry > Sent: Wednesday, April 19, 2006 2:17 PM > To: [email protected] > Subject: Re: [Declude.JunkMail] Madlibs as Bayesian algorithm > frustrators > > We have been seeing these for several weeks now, and SA's > bayes implementation handles it quite well. This from the > Matt Kettler on the SA > list: > ========== > How well bayes poison works depends a lot on your "bayes" > implementation. > Some > "bayes" implementations are fairly susceptible to this. (I > put "bayes" in quotes because not all bayes implementations > are really Bayesian at all. > Actually, most are not, including SA.) > > In particular, the choice of combining algorithm seems to > matter a lot. The use of chi-squared combining, instead of > true Bayesian combining, seems to make SA's bayes rather > resistant to this. > > (note: the use of chi-squared is not exclusive to SA.. many "bayes" > implementations do this, but not all.) > > Another area of influence is the choice of tokens. Words vs > chars, hapaxes, etc all change how a bayes implementation > reacts to poisoning attempts. > > So spammers keep using bayes poison because it works in some > cases. It also doesn't really hurt them much, and sometimes > even helps them, against more resistant implementations. > ========== > > Bill > > ----- Original Message ----- > From: "Colbeck, Andrew" <[EMAIL PROTECTED]> > To: <[email protected]> > Sent: Wednesday, April 19, 2006 1:52 PM > Subject: [Declude.JunkMail] Madlibs as Bayesian algorithm frustrators > > > So... I had reason to dip into my spam folder today and found > a message > that is using some kind of tool to generate madlibs, presumably to pad > the spam so that it seems like a normal message and perhaps to poison > antispam systems that use Bayesian analysis. > > Assuming that your spam filter doesn't catch this message, check out > this paragraph for it's sheer wackiness: > > If the self-loathing rattlesnake has a change of heart about the slyly > frightened fruit cake, then a buzzard returns home. When the > umbrella is > unstable, a briar patch of the canyon accurately sells a pickup truck > for an > inferiority complex to a diskette near a bowling ball. A particle > accelerator about a mastadon earns frequent flier miles, and a fruit > cake > reaches an understanding with the carpet tack. > > Andrew 8) > > > > > --- > This E-mail came from the Declude.JunkMail mailing list. To > unsubscribe, just send an E-mail to [EMAIL PROTECTED], and > type "unsubscribe Declude.JunkMail". The archives can be found > at http://www.mail-archive.com. > > --- > This E-mail came from the Declude.JunkMail mailing list. To > unsubscribe, just send an E-mail to [EMAIL PROTECTED], and > type "unsubscribe Declude.JunkMail". The archives can be found > at http://www.mail-archive.com. > --- This E-mail came from the Declude.JunkMail mailing list. To unsubscribe, just send an E-mail to [EMAIL PROTECTED], and type "unsubscribe Declude.JunkMail". The archives can be found at http://www.mail-archive.com.
