What's up, bot? Google tries new Captcha method • Hacker News Board

Re: What's up, bot? Google tries new Captcha method

#11

Post by henning » Sat, Apr 18, 2009, 7:32 PM UTC

amix wrote: post #7

I have implemented something similar called "Visual captcha", where the user has to pick the cat out from 6 randomized Flickr pictures. The code is freely available and should not be hard to integrate into your own projects. Read more on: http://amix.dk/blog/viewEntry/19338

Is that really effective? Just take some face detection code and have it learn what cat fur looks like instead.

Re: What's up, bot? Google tries new Captcha method

#12

Post by jonknee » Sat, Apr 18, 2009, 7:35 PM UTC

vaksel wrote: post #10

can't someone figure out an anti-spam method that doesn't require a captcha? I mean its not like captchas even work, I'm yet to see one that works 100%

Craigslist's phone verification works well. The downside is it's expensive to run and hard if not impossible to scale globally.

Re: What's up, bot? Google tries new Captcha method

#13

Post by DavidSJ » Sat, Apr 18, 2009, 7:35 PM UTC

markbao wrote: post #3

qeorge wrote: post #2

That's a cool idea, but they'll still have to provide an audio CAPTCHA for blind users, which is easy to solve.

Really? https://www.google.com/accounts/NewAccount

Actually, I think the noise proves his point. The fact that adding so much noise was necessary means computers are pretty good at solving that problem, and it has to be made next to impossible for humans before computers can no longer solve it either.

Re: What's up, bot? Google tries new Captcha method

#14

Post by liuliu » Sat, Apr 18, 2009, 8:08 PM UTC

amix wrote: post #7

I have implemented something similar called "Visual captcha", where the user has to pick the cat out from 6 randomized Flickr pictures. The code is freely available and should not be hard to integrate into your own projects. Read more on: http://amix.dk/blog/viewEntry/19338

the real challenge is to collect enough pictures so that your database could not be broken by brute-force. Of course you can use Flickr's tag to identify it, but there are many mis-matches. Google's method solved this problem because image orientation is a heavily studied problem in computer vision which could take advantage of computer to help creating large visual database and then prune out the easy case for computer.

Re: What's up, bot? Google tries new Captcha method

#15

Post by pavel_lishin » Sat, Apr 18, 2009, 8:14 PM UTC

I think one fascinating aspect of this whole thing is that by creating tougher and tougher captchas, Google and the like are actually helping make great strides in the field of image recognition by forcing spammers to adapt.

Re: What's up, bot? Google tries new Captcha method

#16

Post by pavel_lishin » Sat, Apr 18, 2009, 8:14 PM UTC

ctingom wrote: post #4

markbao wrote: post #3

Earlier quoted context omitted.

Really? https://www.google.com/accounts/NewAccount

Wow, I could barely make out the audio captcha!

But you could still make it out, right?

Re: What's up, bot? Google tries new Captcha method

#17

Post by antiismist » Sat, Apr 18, 2009, 8:29 PM UTC

pavel_lishin wrote: post #16

ctingom wrote: post #4

Earlier quoted context omitted.

Wow, I could barely make out the audio captcha!

But you could still make it out, right?

I couldn't figure out the audio captcha. People who are blind probably have better hearing, so maybe it's easier for them.

Re: What's up, bot? Google tries new Captcha method

#18

Post by snprbob86 » Sat, Apr 18, 2009, 8:33 PM UTC

pavel_lishin wrote: post #15

I think one fascinating aspect of this whole thing is that by creating tougher and tougher captchas, Google and the like are actually helping make great strides in the field of image recognition by forcing spammers to adapt.

The truth of the whole thing is that Google primarily relies on _behavior_ to detect bots. Captures are just an added layer of defense and serve as a pretty good way of seeding the behavior database. If some user appears to be a bot, serve them a captcha. If they fail, then that behavior was bot-like. Google is using captchas as a way to learn image recognition as well as bot behavior patterns. They know full well that they won't be able to rely on captchas for ever, but they will sure as hell collect as much data out of them as possible.

Re: What's up, bot? Google tries new Captcha method

#19

Post by thorax » Sat, Apr 18, 2009, 8:48 PM UTC

amix wrote: post #7

I have implemented something similar called "Visual captcha", where the user has to pick the cat out from 6 randomized Flickr pictures. The code is freely available and should not be hard to integrate into your own projects. Read more on: http://amix.dk/blog/viewEntry/19338

Flickr is harder, I'd use a different database.Doing image searches using existing online images is becoming easier (e.g. TinEye). An evil bot would just do image searches against flickr for each of those images and read/scan the tags there to be sure.

Re: What's up, bot? Google tries new Captcha method

#20

Post by harpastum » Sat, Apr 18, 2009, 9:29 PM UTC

antiismist wrote: post #17

pavel_lishin wrote: post #16

Earlier quoted context omitted.

But you could still make it out, right?

I couldn't figure out the audio captcha. People who are blind probably have better hearing, so maybe it's easier for them.

I've heard a lot of anecdotal evidence that young blind people have better-than-average hearing, but what about the elderly?

I'm not sure anyone I know over 70 years old could pass either of those captchas. I guess the only consolation is that most people that age often have younger people sign up for them.