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Breaking the 4Chan CAPTCHA

nullpt.rs

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Re: Breaking the 4Chan CAPTCHA

#181

Post by Pikamander2 »

PUSH_AX wrote: post #168
wraptile wrote: post #135

Earlier quoted context omitted.

That's kinda what every major captcha distributor does already! Even before captcha is being served your TLS is first fingerprinted, then your IP, then your HTTP2, then your request, then your javascript environment (including font and image rendering capabilities) and browser itself. These are used to calculate a trust score which determines whether captcha will be served at all. Only then it makes sense to analyze…

In that case why do I ever receive a captcha?

It adds another layer of analysis. For example:

If the user solves the CAPTCHA in 0.0001 seconds, they're definitely a bot.

If the user keeps solving every CAPTCHA in exactly 2.0000 seconds, each time makes it increasingly likely that they're a bot.

If the user sets the CAPTCHA entry's input.value property directly instead of firing individual key press events with keycodes, they're probably either a bot, copy-pasting the solution, or using some kind of non-standard keyboard (maybe accessibility software?).

Basically, even if the CAPTCHA service already has a decent idea of whether the user is a bot, forcing them to solve a CAPTCHA gives the service more data to work with and increases the barrier of entry for bot makers.

Re: Breaking the 4Chan CAPTCHA

#183

Post by ggu7hgfk8j »

brian-armstrong wrote: post #128
bawolff wrote: post #58

There is a reason why people moved away from distorted text based captcha. We are basically at the point where computers are better at them then humans. https://www.usenix.org/system/files/conference/woot14/woot14... is a paper on the subject i think is really interesting However a surprising amount of text based captchas can be solved in a few line shell script of, using imagemagik to convert to greyscale, dilate an…

Makes me wonder what comes next. Could we create a forum where every member must do a 15 minute video interview with a moderator? I know this "doesn't scale" but I think it could make for a funny gimmick.

We are increasingly moving to ID checks. Australia law just now. For all its faults it solves spam as side effect.

Re: Breaking the 4Chan CAPTCHA

#184

Post by sigmoid10 »

Pikamander2 wrote: post #179

> The official TensorFlow-to-TFJS model converter doesn't work on Python 3.12. This doesn't seem to really be documented. > TensorFlow.js doesn't support Keras 3. I tried getting into some casual machine learning stuff a few years ago and more or less gave up because of stuff like this. It was staggering how many recent tutorials were already outdated, how many random pitfalls there were, and how many "getting starte…

As someone who has been working in ML for years, I can only recommend to stay away from anything recent. Grab an old bayesian statistics textbook and learn the fundamentals, then progress to learning the major frameworks like Pytorch. Try to write every part of a CNN, RNN and Transformer architecture and training pipeline yourself the first time (including data loaders, but maybe leave out CUDA matrix kernels). Stay the hell away from wrappers for other people's wrappers like Langchain. Their documentation is often not just outdated, but flat out wrong regarding the fundamentals. Huggingface is great if you know the basics and thus how to fix things if their standard wrappers break.

Re: Breaking the 4Chan CAPTCHA

#185

Post by matchamatcha »

brian-armstrong wrote: post #128
bawolff wrote: post #58

There is a reason why people moved away from distorted text based captcha. We are basically at the point where computers are better at them then humans. https://www.usenix.org/system/files/conference/woot14/woot14... is a paper on the subject i think is really interesting However a surprising amount of text based captchas can be solved in a few line shell script of, using imagemagik to convert to greyscale, dilate an…

Makes me wonder what comes next. Could we create a forum where every member must do a 15 minute video interview with a moderator? I know this "doesn't scale" but I think it could make for a funny gimmick.

When I was a teenager, I stumbled upon a music forum that required phone interviews for signing up. They had other interesting sign up rules, like you could not have silly user names (judged by the admin). I guess it served as an effective filter for their member base..

Re: Breaking the 4Chan CAPTCHA

#186

Post by poincaredisk »

bawolff wrote: post #58

There is a reason why people moved away from distorted text based captcha. We are basically at the point where computers are better at them then humans. https://www.usenix.org/system/files/conference/woot14/woot14... is a paper on the subject i think is really interesting However a surprising amount of text based captchas can be solved in a few line shell script of, using imagemagik to convert to greyscale, dilate an…

Small? From your own link, recaptcha v3 takes 10-15s and costs $1.3 for 1000 captchas. This is actually huge, and cost prohibitively expensive for many things where you would want to use it (like scrapping a large website).

Re: Breaking the 4Chan CAPTCHA

#187

Post by brodo »

antirez wrote: post #13

Appropriate response by 4Chan to this: simplify the human work given that anyway it's simple to solve via NNs. We are at a point where designing very hard captchas has high probabilities to increase the human annoyance without decreasing the machine solvability.

I am totally in favor of increasing the annoyance of 4chan users.

Re: Breaking the 4Chan CAPTCHA

#188

Post by poincaredisk »

codetrotter wrote: post #55
antirez wrote: post #13

Appropriate response by 4Chan to this: simplify the human work given that anyway it's simple to solve via NNs. We are at a point where designing very hard captchas has high probabilities to increase the human annoyance without decreasing the machine solvability.

> simplify the human work given that anyway it's simple to solve via NNs. We are at a point where designing very hard captchas has high probabilities to increase the human annoyance without decreasing the machine solvability Or disallow free users to post at all, and require everyone to buy the 4chan Pass for $20 USD per year if they want to post. https://4chan.org/pass This is already available to not have CAPTCHA.…

At this point I have to wait 90 seconds before making every post. (maybe because I don't persist cookies). I posted very rarely, but now I just stopped - I get it when someone shows me the door.

Re: Breaking the 4Chan CAPTCHA

#190

Post by poincaredisk »

encom wrote: post #167
antirez wrote: post #13

Appropriate response by 4Chan to this: simplify the human work given that anyway it's simple to solve via NNs. We are at a point where designing very hard captchas has high probabilities to increase the human annoyance without decreasing the machine solvability.

4chan doesn't care about human annoyance. They just started doing a 15 minute post delay, which is infuriating. I had to whitelist 4chan in Cookie AutoDelete.

Hi fellow cookie autodeleter, I experienced the same thing, but I just decided to stop posting. Whitelisting felt too much like giving in to terrorists. I'm considering just not going there in the future. Maybe after all this time I will finally be free.
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