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 and undilate, then pass to teserract
However there are also sites like https://2captcha.net , so really captchas are more like putting a small min amount of effort.
Just because you can technically crack them doesn't mean they're useless.
There's a significant amount of time, skill and effort that went into the solution from this post, and the end result doesn't generalize well (you'd have to start all over for a different kind of captcha).
The vast majority of spammers would not be able to replicate this; those who do would either make money legitimately, or focus their skills on juicier targets (if you have AI/ML skills and want to do nefarious things there are other options that pay much better than spamming).
Such captchas still work well at raising the cost of successful spamming above the expected payoff from said spam.
So, I do this type of AI development for solving CAPTCHAs.
I can't get any real jobs that pay me for my more advanced skills. My primary sins were going to a second/third-tier university and some performance concerns in a portion of my previous roles due to divorce and burn-out. I make $80k/year in government IT, and $30-150k/year as the "AI" guy in a small 2-5 person group that offers a CAPTCHA-breaking API.
The spammers aren't the ones replicating this. They just pay B2B rates (combo of SaaS + Consulting, depending on client needs) to help them remove the roadblocks.
I am a nafri with a PhD and engineering experience (with europeans), I can't make good living going the traditional way either with with remote jobs being impossible and no luck landing a visa.. I have built custom solutions for big name EU companies to keep an eye on the competition through scraping. captcha solving cloudflare bypass is a great part of that. Getting back at companies making the UX bad with captcha does feel good also.
Why do you do this?
While I can appreciate the technical achievement, you know most users of forums and imageboards donât want any AI content at all.
If there were a totally 100% aboveboard way to do this in a net transfer of utility from Tessier-Ashopool SA to the typical web surfer I would be a superfan.
Is your company hiring? :)
Interesting, subtle difference but I always thought of captchas as having computational difficulty, but that's clearly not the point as you say. The cost is not compute but developer time.
If you manage crack it at 1mhz per captcha or 1ghz or 1000ghz, it makes no difference, as the bottleneck is the network identifier (ip address/block)
While still a type of PoW, these economics are different than offline mechanisms like password hashing or crypto. Where a 1ghz cost is still significantly different than 1mhz.
The watershed of "good enough at programming to just get a real job" vs "can code enough to be really annoying to businesses, but not enough to hack it as a dev" is a lot more on the annoying side than you'd think.
I say this with the chagrin of someone who works on a cool software product that is also coincidentally really well-shaped to make people want to abuse it.
Captchas are now useful to distinguish well-intentioned bots (they stop whenever they see captcha) from malicious ones, which solve them, but still behave a lot like bots.
Well-intentional bots are first-class citizens
Wouldnât a well-intentioned bot follow robots.txt anyway?
Do you complete the circle and do the good bot bad bot classification with a mod bot?
I think captchas are just another lind of defense to make it harder for actors abusing the system. It's not a solution, just a little (getting outdated) fortification.
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..
The silly username thing goes a bit too far though. It just means the admin will subjectively apply other rules. Doesnât sound like a lot of fun.
private torrent trackers are/were doing that. It was really just to make sure you understood how p2p culture works and what the expectations are, and really easy to pass if you just followed a guide. However, I did see many people fail their interview.
The famous RED tracker has a full on technical interview asking about:
* Audio Formats
* Transcoding
* Spectral analysis
and more.
This is the interview prep website: https://interviewfor.red/en/index.html
Was there ever video interviews? Admittedly I wasnât really paying attention but back when I was getting into what it was only IRC, and these days it still seems to be IRC anywhere that does interviews (otherwise class-restricted forum invites).
[dead]
We are increasingly moving to ID checks. Australia law just now. For all its faults it solves spam as side effect.
It also makes it 100x more likely for you IDs to leak online as KYC companies are valuable targets that get hacked every month
There are lots of random ID documents available on dark networks however.
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).
The part about bad Keras<->Tensorflow.js interop is classic Tensorflow. Using TF always felt like using a bunch of vaguely related tools put under the same umbrella rather than an integrated, streamlined product.
Actually, I'll extend that to saying every open source Google library/tool feels like that.
related (15 days ago)
https://news.ycombinator.com/item?id=42130881 on Francois Chollet is leaving Google
> "Why did you decide to merge Keras into TensorFlow in 2019": I didn't! The decision was made in 2018 by the TF leads -- I was a L5 IC at the time and that was an L8 decision.
something something Conway's law
Semi-related but I needed a CAPTCHA on my site[0] mainly to block comment form spam and settled on repurposing a fun method Iâd seen before. Is definitely not foolproof (or hard at all), but I really liked making it.
Reminds me of the Doom captcha.
99% certain this is where I copied the idea from.
It says I've been blocked when I try to view that. Not on a VPN.
The site runs off of a tiny little server at home so Iâve got some very aggressive firewall rules. Anything from the usual bad countries, certain signatures etc are blocked. Reduced traffic to 1% of previous load.
What are the bad countries? Russia and china?
Are you in a safari browser?
Chrome android
No way, that is a cool fucking captcha!!
If you're into this, here's my 2014 breakdown of the Silk Road CAPTCHA: https://github.com/mieko/sr-captcha
I wonder if it would be better to pretend to have a captcha but really you are analysing the user timing and actions. Honestly I half suspect this is already going on.
If you wanted to go full meta "never go full meta" you would train a AI to figure out if the agent on the other side was human or not. that is, invent the reverse turing test. it's a human if the ai is unable to differentiate it's responses from normal humans responses. as opposed to marketing human responses.
Well now I have to go have a lay down, I feel a little ill from even thinking on the subject.
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 captcha's input but by that time you caught 90% of bots either way.
The amount your browser can tell about you to any server without your awareness is insane to the point where every single one us probably has a more unique digital fingerprint than our very own physical fingerprint!
This is how ClownFlare and its ilk, make life hell on the internet, when you use a "weird" browser on a "weird" OS.
My experience is that IP reputation does a lot more for Cloudflare than browsers ever did. I tried to see if they'd block me for using Ladybird and Servo, two unfinished browsers (Ladybird used to even have its own TLS stack), but I passed just fine. Public WiFi in restaurants and shared train WiFi often gets me jumping through hoops even in normal Firefox, though.
I can't imagine what the internet must be like if you're still on CG-NAT, sharing an IP address with bots and spammers and people using those "free VPN" extensions donating their bandwidth to botnets.
Would it be possible to serve a fake fingerprint that appears legitimate? Or even better mimic the finger print of real users who've visited a site you own for example?
yep, but it can get tricky.
some projects worth checking out: https://github.com/refraction-networking/utls https://github.com/berstend/puppeteer-extra
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.
I found several websites switched to 'press here until the timer runs out', probably they are doing the checks while the user is holding their mouse pressed, it would be trivial to bypass the long press by itself with automated mouse clickers.
Re: your last paragraph, https://coveryourtracks.eff.org/
EFF have been running this for years. Gives an estimate about how many unique traits your browser has. Even things like screen resolution are measured.
That's what reCAPTCHA does.
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.
This is already available to not have CAPTCHA. So if CAPTCHA is totally ineffective, it follows that they should do away with CAPTCHA and free users being able to post at all and everyone should buy the 4chan Pass if they want to post.
This kills the board. Users will go elsewhere, fuck all people pay for pass.
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.
Agreed, charging for accounts is the only halfway viable solution I have seen any service use that gives a sizable downtick in the sheer number of bots/spam.
Of course it's not perfect, and it will still happen, but I have yet to hear any better solutions. Please prove me wrong though!
This is known as a Sybil [1] attack and it lays the groundwork for stuff like Adam Backs hashcash [2] protocol and itâs basically why things like proof of work [3] have a monetary value today.
Very chicken and egg this entire field- defending against the spammers while simultaneously operating a âfreeâ system. How to do it without making it prohibitively expensive to join the systemâŚ
Any free system will be abused yada yada yada
[1] https://en.wikipedia.org/wiki/Sybil_attack
That would work. It would also kill the site.
We've been stuck at that point for at least 5, if not 10, years.
Just use Worldcoin retina scans next
What is NN?
"AI" but pre-COVID
Oh my!
Is the oversimplification from "deep neural network" into "AI" caused by the prevalence of brain-fog due to long COVID?
In my opinion the granddaddy of all 4chan CAPTCHA busts is still Yannick Kilcherâs GPT-J tune on âRaiders of the Lost Kekâ set, and might be the coolest thing an LLM has ever done on video: https://youtu.be/efPrtcLdcdM?si=errY0PrEhnX9ylDw
Nearly a full minute of disclaimers and warnings about 4chan. That's got to be a record.
>I released the model, the code and I evaluated the model on a huge set of benchmarks and it turns out this horrible, terrible, model is more truthful-yes more truthful-than any other GPT out there
> 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 started" guides assumed you were already an expert.
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.
Any book you would recommend?
You can try Theodoridis if you can find a first or second edition. It is old enough to not be diluted by the recent craze but still recent enough to cover all the necessary fundamentals. There is also a new edition coming out soon, but that seems to have been heavily tainted by the ChatGPT hype.
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