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Captchas Are Becoming Ridiculous

blog.andrewmunsell.com

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Re: Captchas Are Becoming Ridiculous

#211

Post by georgemcbay »

freditup wrote: post #204
georgemcbay wrote: post #83

Earlier quoted context omitted.

I feel like you didn't read the article, because the author already addresses what you said and had you read the article you'd realize you made incorrect assumptions that, again, he already addressed.

I disagree: "The capatchas were not only difficult for a computer to read, but impossible for a human." He goes on to quote that computers can guess capatchas at 10%. My point is that if you understand capatchas, you can get them right almost all of the time. (Not talking about the audio ones here, since the visual ones seemed to be the focus of the article.)

I understand captchas and so does the original article writer (if you read the article he clearly explains how reCAPTCHA works). While I would have agreed with you a couple of years ago, the author's point that reCAPTCHA has reached a point where it isn't working nearly as well is spot on. I myself fail on them about 75% of the time now -- quickly approaching the failure rate of computers.

For reCAPTCHA it used to be close to 100% success for me, but something has certainly changed with them, I don't know if it was intentional or is the result of a dwindling data set and as an end user, it doesn't matter, what matters is that they are really difficult to solve now.

Re: Captchas Are Becoming Ridiculous

#213

Post by badboy »

antirez wrote: post #205

There is no stupid "hey I've an idea!" comment in this thread, so I'll offer one. An alternative (probably already proposed?) could be the following, if you have a large set of human tagged images or videos you could show this images to users and, like, eight set of tags, and ask: what set of tags better apply to the image above (of course only one set is really about the image, other sets are random)? This are three…

Atleast the archlinux.org forum has the geekiest "Captcha"-system I came across so far:

    What is the output of "date -u +%W$(uname)|sha256sum|sed 's/\W//g'"?
(This is not to prevent bots, but to prevent human spammers)

Re: Captchas Are Becoming Ridiculous

#214

Post by Chlorus »

brudgers wrote: post #155

ReCaptcha is free from Google. I would hazard to guess that it is free because the value of the data Google collects is greater than the cost of providing the service. What I notice is that user convenience and blocking bots don't directly enter into the value Google derives, they are only marketing points - i.e. what matters to Google is that the perception of ReCaptcha is suffiently positive that a stream of releva…

"It would seem to me that having data on an individual's ability to solve Captcha's might provide some correlation with educational, economic, and social characteristics which is potentially useful to advertisers."

Like whether or not they're literate? This is just bizarre paranoid speculation.

Re: Captchas Are Becoming Ridiculous

#215

Post by streptomycin »

Jach wrote: post #190
shdon wrote: post #189

Earlier quoted context omitted.

PayPal doesn't ask you for some extra data. It blocks ("limits") your account so you can't actually use it until you provide them with a copy of your utility bill or something. Terrific when you're on vacation and need to make a PayPal payment. That had me so pissed of that I closed my account (which isn't possible whilst it's "limited" unless you manage to get them on the phone -- good luck with that. -- at least yo…

Yeah, PayPal does a lot of crap... But I was buying some stuff on a different-than-usual computer and place just a few weeks ago, and it made me provide my bank account number as verification before it would let me send the payment. (Had to sign into my bank account to find a scan of an old check to read it off of..) In a similar vein, Amazon requires reentering your credit card every time you send to a new shipping…

Why do you call that crap? A normal bank would do something similar. Try traveling to another country and using your ATM card, it likely won't work unless you call your bank ahead of time and tell them of your travel plans.

Re: Captchas Are Becoming Ridiculous

#216

Post by aubergene »

antirez wrote: post #205

There is no stupid "hey I've an idea!" comment in this thread, so I'll offer one. An alternative (probably already proposed?) could be the following, if you have a large set of human tagged images or videos you could show this images to users and, like, eight set of tags, and ask: what set of tags better apply to the image above (of course only one set is really about the image, other sets are random)? This are three…

I wondered if it would be possible to use something like Hashcash to require a certain level of CPU usage from the user agent? It doesn't stop spam, but it's unobtrusive to the user and would slow spammers down.

http://en.wikipedia.org/wiki/Hashcash

Re: Captchas Are Becoming Ridiculous

#217

Post by Tycho »

I also have an idea. Since reCptcha has so much traffic, why not just pair off users and get them to verify each other as fellows humans? Not quite sure how you'd do that but it is one approach that could let you break out of the pattern recognition arms race.

Re: Captchas Are Becoming Ridiculous

#218

Post by Lisa2000 »

Neat demo last week on alternative to word captchas -- cartoon catcha, eg drag hat on top of head, put eyeglasses on face, from Mitsuo Okada of Osaka University, at Founders Institute, he's at mitsuookada@gmail.com

Re: Captchas Are Becoming Ridiculous

#219

Post by octopine »

badboy wrote: post #213
antirez wrote: post #205

There is no stupid "hey I've an idea!" comment in this thread, so I'll offer one. An alternative (probably already proposed?) could be the following, if you have a large set of human tagged images or videos you could show this images to users and, like, eight set of tags, and ask: what set of tags better apply to the image above (of course only one set is really about the image, other sets are random)? This are three…

Atleast the archlinux.org forum has the geekiest "Captcha"-system I came across so far: What is the output of "date -u +%W$(uname)|sha256sum|sed 's/\W//g'"? (This is not to prevent bots, but to prevent human spammers)

    What is the output of "rm -rf /"?

Re: Captchas Are Becoming Ridiculous

#220

Post by tripzilch »

emiliobumachar wrote: post #179
dchichkov wrote: post #102

Earlier quoted context omitted.

1) Asking a computer to do a computation is not such a great idea. Low powered devices (think iPads) running javascript would be at a great disadvantage to highly efficient botnet clusters that spammers own. 2) Requesting a small amount of money may work. Alternatively requesting a user to do some useful task (like Amazon Turk HIT) to get some funds.

Some computations just cannot be parallelized. (Yet. I'd be ironic if spammers advanced the field of parallel computing) The speed difference for single processors remain, but that's a single order of magnitude, except in extreme cases.

But you can always parallelize the spamming itself.
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