Comments on: Captcha cracking in JavaScript with Canvas and neural nets

By: sourceRoot

sourceRoot — Thu, 24 Jun 2010 23:23:35 +0000

The “spam question” is far worse at stopping spam than captcha :)

Most of the effective spammers use low wage labor to post somehting kinda on topic like nice post I agree with so and so… link

Captchas have been dead for a long long time

By: Bigbx

Bigbx — Fri, 14 Aug 2009 19:25:12 +0000

Why complicate when there ready firefox plugin for this? Use google and spend time on smarter things.

By: ilazarte

ilazarte — Mon, 26 Jan 2009 17:10:20 +0000

I guess this marks the end of captchas!

Welp, let me just finish my post here, by answering this Spam Question located at the bottom of this form…

By: ThomasHansen

ThomasHansen — Mon, 26 Jan 2009 14:19:12 +0000

@Snyke and ffreak
You divide the image into a n matrices where n is the number of unique elements you find in it (characters) then you treat every matrix as a vector and check the “direction” according to your precompiled “solution”…
Normally *WAY* faster then NN and doesn’t lock up or any of the other “great problems” that NN comes with…
.
It’s quite common according to my knowledge for OCR and similar things…
.
not sure how good it would work for captchas though since they tend to “mess” with the surface making it more difficult to recognize the pattern…
.
Don’t get me wrong, I think NNs in JavaScript sounds hilariously cool, though I think the Linear Algebra solution would perform *seriously* faster (if possible)
.
Beside it was a *question* not an attack … ;)

By: Snyke

Snyke — Sun, 25 Jan 2009 20:04:23 +0000

Agreed with ffreak, there is currently no better option to NN for pattern recognition.
Still it would be interesting to see how this works with recaptcha which is a project for using distributed users entering captchas to digitalize old scriptures.

By: ffreak

ffreak — Sun, 25 Jan 2009 15:47:29 +0000

@ThomasHansen
Because patterns recognition is what neural networks do great and they are easy to implement. I have no idea how anyone could use “linear algebra” instead – I suppose it would be insanely complex.

By: ThomasHansen

ThomasHansen — Sun, 25 Jan 2009 11:59:18 +0000

Impressive!
Though why not use Linear Algebra instead of Neural Networks…?
I assume NN have way higher processing demands and still less right hits…?
Comments…?

By: Jordan1

Jordan1 — Sun, 25 Jan 2009 01:52:55 +0000

Wow its even better than the best PHP captchas! They should put it in one of those annual best captcha competitions. Its inevitable that neural networks would one day surpass human perception.

By: nunziofiore

nunziofiore — Sat, 24 Jan 2009 17:14:33 +0000

lucky ajaxian login goes again :)

this is a bit complexed but finally i understood it… great…
anybody know something or can suggest some link about MooTools+CANVAS+[IPHONE|ANDROID] ?
Does the browser mounted on that device support it?

By: oopstudios

oopstudios — Sat, 24 Jan 2009 11:44:18 +0000

Excellent read! But it begs the question, are there systems that could crack a form that is *activated* with javascript (thus the source doesn’t represent the true form)? I’m not up-to-date with the modern spiders…