Comments on: Logic based CAPTCHA to beat the blog spam bots

By: Andrew

Andrew — Mon, 14 Feb 2011 15:13:07 +0000

Math captcha (logically) is only one of various types. What is captcha will as some short video clip where will need to answer to some question? Or where will need to solve easy puzzle? It will make your page more interactive and interesting :) You can read related article here

By: Sinvex

Sinvex — Wed, 26 Jan 2011 00:37:12 +0000

Problem with logic based captcha is that you cannot have the computer generate an infinite amount of different ones. This leads to you having to constantly do more work to keep new ones up there as someone could easily just sit around and record a database of them and then sell that to spammers or use themselves. This may sound like some tedious task nobody would want to do but you can easily contract such a thing out to a random person similar to the “Chinese gold farmer” industry in MMO’s (there are tons of people SOMEWHERE in the world who are willing to do all this stuff for next to nothing.)

By: ali

ali — Thu, 28 Jan 2010 01:28:00 +0000

hi,

i have written a script that produces a obscure mathematical equation to be solved by the user for captha. the equaton is obscured by. 1)having words rather than digits. 2) surrounding words by special characters 3) randomly changin these characters. examples.

1) s^{Fourty:Five|^s +Plus+ s^|Two}^s =
2) +Plus+ =
3) *?Fifteen|* +Plus+ *|Seven?* =
4) dd#Twenty~Three#bb +Plus+ dd#Two#bb =
5)+Plus+ =

as a experienced spam victim – could you possibly tell me how easy or difficult would my captha be to break. plz see example above, it changes on attempt/submit including the two words that comprise numbers of 21 and above.

thanks.

By: Jonathan

Jonathan — Wed, 02 Dec 2009 00:05:34 +0000

Where can I get this? I have looked and I am not seeing it anywhere?

By: Breitling replica watches

Breitling replica watches — Tue, 13 Mar 2007 00:54:22 +0000

I have seen techniques to prevent spam even nicer. There is one (I can’t remember where) that besides a captcha it also count how many letters you actually typed, how many copy/paste-s you did, if there are href’s and so on. Very complex and highly effective.

By: toyota

toyota — Thu, 15 Feb 2007 11:27:11 +0000

The Regard! Long ago

By: Jeff Schiller

Jeff Schiller — Thu, 14 Dec 2006 19:57:27 +0000

I did that on my own blog very recently. It simply asks a breezy math question (like 4+3). Spambots doing OCR would either think the answer is “4+3″ or “4t3″. Either way, I win and they lose…