
AI Startup Says It Has Defeated Captchas - Larx-3
http://www.technologyreview.com/news/520581/ai-startup-says-it-has-defeated-captchas/
======
ColinWright
From the article:

    
    
        "Captcha" stands for "completely automated
        Turing test to tell computers and humans apart."
    

No it doesn't - where's the word that starts with "P"?

According to Wikipedia "CAPTCHA" is an acronym for "Completely Automated
Public Turing test to tell Computers and Humans Apart" (and is apparently a
trademark of Carnegie Mellon University, which I didn't know.) Even that's a
really bad backronym.

Google's reCAPTCHA page[0] says the same thing, and even attributes it:

    
    
        The term CAPTCHA (for Completely Automated Public Turing Test
        To Tell Computers and Humans Apart) was coined in 2000 by Luis
        von Ahn, Manuel Blum, Nicholas Hopper and John Langford of
        Carnegie Mellon University.
    

That should then be CAPTTTTCAHA. Doesn't quite have the same ring to it.

Given the term CAPTCHA it seems that a "better" (by some definition) backronym
would be:

    
    
        Completely Automated Process to Tell Computers and Humans Apart.
    

At least with that one only the particles "to" and "and" are left out of the
abbreviation.

More on topic though, I long for the day when off-the-shelf systems that even
script-kiddies can use are able to break CAPTCHAs with ease - that's when
they'll finally die. TicketMaster gave up on using the standard CAPTCHAs
earlier this year[1], and I'd love to see something better replace it.

[0]
[http://www.google.com/recaptcha/captcha](http://www.google.com/recaptcha/captcha)

[1]
[http://www.bbc.co.uk/news/technology-21260007](http://www.bbc.co.uk/news/technology-21260007)

~~~
mcherm
> I'd love to see something better replace it.

So long as the "better" solution is something OTHER than "Please log in to
your Facebook account."

------
benhamner
This is cool, but there's no indication from the article that it's novel, or
that it's better than existing methods.

The article linked to 28 other different systems that have claimed to beat /
demonstrated beating captchas at some point:
[http://www.karlgroves.com/2013/02/09/list-of-resources-
break...](http://www.karlgroves.com/2013/02/09/list-of-resources-breaking-
captcha/).

Without a performance comparison to existing methodologies on a benchmark
dataset and precise details on the models, this is a neat marketing demo and
nothing more.

------
gkoberger
They literally have a better hit rate than I do when it comes to captchas.

~~~
girvo
My first thought was that I'd love to run this myself. Not to spam, but to be
able to skip Captchas.

That's a really sad thought.

~~~
cclogg
Yeah totally. I swear there's been captchas that were unsolvable (to my eye)
lol.

------
bjterry
> or let you know how many calories you’re about to eat by looking at your
> lunch.

I have previously told some people that this is the holy grail of dieting
apps. The difference in ease of use between entering all of the items in your
meal, one by one, and just taking a photo, would be a game changer. Of course,
this is just a throwaway example in the article so they probably haven't done
any of the work that would be required to make this a reality (aside from the
vision processing, of course). I think it could be done with thousands of
human raters estimating for you instead of a machine learning system, but I
was skeptical of whether it could be profitable enough to justify it as a
startup on a risk/reward basis. One day, maybe we'll see it though.

~~~
sjtrny
The hard part about this problem is getting the scale and thus volume of the
objects right. How big is that bowl holding your cereal?

~~~
millstone
And is that Coke or Diet Coke?

~~~
vidarh
And have you "hidden" a dash of syrup or 100g of nuts under the milk.

But it'd be useful for rough estimates for things like restaurant meals, with
the aid of a menu.

------
ChrisNorstrom
Computers can simulate everything from visual character recognition to mouse
movements and everything else we do online.

My prediction is that Google will one day enter the "Bot Recognition Market".
They've got so much data on everyone and their browsing habits from Gmail, to
Adsense, to Search results, to Google Analytics. Their cookies, browser,
javascript, and ads follow you around all over the internet. They're the only
company capable of putting all that data together and returning via API: "This
user is a real person, we've analyzed 3 years of data from them, go ahead and
let them sign up"

Or returning: "User is a bot, their IP has no purchases, no google account, no
search requests, no adsense impressions, etc..."

~~~
babby
The part about Google offering a sort of vetting service sounds quite
plausible, in a "Oh, shit" kind of way. For those of us that try to be
anonymous we could have further encumbrance dealing with not being "Google
Verified™".

------
TomGullen
CAPTCHA's did nothing to prevent spam for us.

However simply disabling users < 3 posts being allowed to post hyperlinks got
rid of 99% of spam.

We initially allowed plain text links but spammers seemed happy to just post
them.

Spammers want to post hyperlinks, without that ability they can't do anything.

~~~
borplk
Just an idea:

Make links remain as plain text (so they are plain text as far as google is
concerned)

then use javascript to turn them into clickable links when the user mouse is
over or near the link so the user can still click on them.

~~~
TomGullen
Spammers still relentlessly spammed us when we turned them into plain text
links. Removing the ability to post plain text links was the only thing that
stopped them.

No idea why they seemed happy to post plaintext links but there you go!

------
muglug
Here's a video demonstration:
[https://vimeo.com/77431982](https://vimeo.com/77431982).

Apart from one blip (scepticism vs sccpticism) it outperforms me.

------
ChrisNorstrom
As far as I know bots, even advanced ones, have an extremely hard time with
dotted fonts. Just change the Captchas to use some really dotted or unique
fonts where the letters are made up of smaller elements that don't connect.
You can extend the life of Captchas for a few more years.

[http://fontspace.com/malwin-b%C3%A9la-h%C3%BCrkey/merkur](http://fontspace.com/malwin-b%C3%A9la-h%C3%BCrkey/merkur)

[http://fontspace.com/honey-and-
death/dotline/8617.charmap](http://fontspace.com/honey-and-
death/dotline/8617.charmap)

[http://fontspace.com/bythebutterfly/bubble-
bath](http://fontspace.com/bythebutterfly/bubble-bath)

[http://fontspace.com/jecko-development/jd-lcd-
rounded](http://fontspace.com/jecko-development/jd-lcd-rounded)

Eventually, the spammers will make a bot to analyze the distance between dots,
group them into letters, and the race will be on to use other methods. I see
this as a never ending virus/immunity battle. We're pretty much at the end of
Captchas. Other methods like mouse movement, surfing time, scrolling, etc...
can all be mimiced as well. Computers can or will be able to simulate humans
very well, even our imperfections.

~~~
turing
You might find these examples from LeNet interesting. They are examples of
unusual styles of digits that the system correctly recognized, made of dashed
lines, bubbles, and dots. Granted this system only recognized digits, but it's
not exactly a stretch to jump to the character set typical of Captchas.

[http://yann.lecun.com/exdb/lenet/weirdos.html](http://yann.lecun.com/exdb/lenet/weirdos.html)

------
thrush
This was literally a homework assignment in a security course I took during
undergrad so excuse me if I'm not impressed. Also, from the comments it's
clear that the benefits of Captchas are being overlooked. Google purchased
ReCaptcha some time ago and uses it to solve difficult OCR problems by using
human input. In Recaptcha you'll notice that there are always two words, and
one tends to be easier than the other. The one that is easier has a known
result and is used for security, the other one is unknown and Google will use
people's guesses to find its true result. Even if this startup was to
consistently solve the hardest Captchas on the internet, it would actually be
a good thing because we would have better OCR. Realistically this won't happen
and ReCaptcha will just use harder images all the time if it needs to.

------
lucisferre
Good, Captchas should have stopped being a spam prevention measure years ago.

~~~
olalonde
Do you have an alternative to suggest?

~~~
klearvue
We use honeypot field and timegate trap on our site forms - so far very
successfully.

~~~
bbrizzi
I know what a honeypot (fake field that only bots fill out) but what's a
timegate trap? Googling didn't bring up anything relevant.

Does it check how long it took the user/bot to fill up the form and dismisses
it if it was too fast?

~~~
borplk
yes as far as I know you got it right, you somehow keep track of when the form
was presented to the user and compare that with the current time when a
response comes in

------
sigmike
"It's a textbook example of AI hype of the worst kind

Hype is dangerous to AI. Hype killed AI four times in the last five decades.
AI Hype must be stopped."

Yann LeCun,
[https://plus.google.com/104362980539466846301/posts/Qwj9EEkU...](https://plus.google.com/104362980539466846301/posts/Qwj9EEkUJXY)

------
perfmode
Advances in storage and compute have led to a disturbing fetishization of
machine learning.

While the modern Machine Learning Movement makes sense in a historical context
and is a reasonable reaction to the disappointing returns from symbolic
inference during the early days of AI research, it is terrifying that the
research community is satisfied to rely on big data and statistical methods to
carry us forward.

Few among us recognize the need to prioritize the study of the human brain.
Even fewer are placing their bets on intelligent computer systems seeded with
neurologically-inspired designs.

Vicarious gets it.

How long before others see the writing on the wall?

Now is the time to stop reacting. Now is the time to consider the field in a
broad context and develop a balanced, holistic approach.

Consider this a wake-up call.

[http://blog.perfmode.com/the-noml-movement/](http://blog.perfmode.com/the-
noml-movement/)

~~~
unlikelymordant
I'm not sure I understand. "Few among us recognize the need to prioritize the
study of the human brain", a great deal of the state of the art machine
learning results are based on deep learning, which are algorithms that are
"neurologically inspired" as you would put it. You seem to have a problem with
big data and statistical methods, but one of the main deep learning
algorithms, RBMs, _are_ statistical methods.

Also, could you expand on what a "balanced, holistic approach" to machine
learning is?

~~~
perfmode
"Even though an amplifier and a computer are both made of transistors, they
have almost nothing else in common. In the same way, a real brain and a three-
row neural network are built with neurons, but have almost nothing else in
common." \-- Jeff Hawkins (On Intelligence)

One example is that most NNs neglect the time domain.

A balanced approach recognizes the importance of learning from data, but does
not _rely_ on big data. A holistic approach entails a close examination of
biological learning systems.

~~~
varjag
As a counterpoint, nearly all human technical advances (flight, propulsion,
energy, computation) did not entail examination of biological systems. And
ANNs in particular share a host of problems with statistical techniques:
black-boxish behavior with lack of human-accessible state introspection and
poor tractability.

~~~
chongli
_black-boxish behavior with lack of human-accessible state introspection and
poor tractability._

I have a philosophical question in response to this. Is it even possible to
have _intelligence_ without it being a black box? Are people willing to call
something intelligent if they completely understand how it works?

~~~
varjag
Well my point was rather practical than philosophical: if you take a human at
say classification task, they'd be able to explain why they identify bicycle
as bicycle and not, say, bulldozer. You can't readily have this with ANNs; all
you have is a bunch of weight coefficients and feedback loops.

~~~
chongli
_if you take a human at say classification task, they 'd be able to explain
why they identify bicycle as bicycle and not, say, bulldozer._

I don't think this is such an easy task. In the professional world of
scientific taxonomy there are many problems with classification. The problem
seems to stem from the tension between intensional and extensional
definitions.

~~~
varjag
Yes but you still are able to verbalize these problems, quite unlike when you
stuck with a misfiring ANN. In symbolic approaches, e.g. inference engines,
you have comparable explanatory facilities.

------
ColinWright
Video of the system in action submitted here:

[https://news.ycombinator.com/item?id=6626405](https://news.ycombinator.com/item?id=6626405)

------
bparsons
So they have invented the world's best OCR software?

~~~
vidarh
Not really, unless your corpus consists mainly of hopelessly distorted
characters.

They state a captcha solving rate of around 90%.

For OCR to be cost-competitive, you typically need it to be correct on about
98% of characters or more; below that and it is typically cheaper to have a
human typing in the text than to have a human correct OCR'd text.

Modern OCR engines typically do better than 99% on text that isn't really
badly damaged (my MSc. dissertation was on error correction in OCR, and as
part of that I tested some engines with pages that had been crumpled,
intentionally damaged with sand and liquids, and even then many of the engines
managed more than 99%).

~~~
gondo
hi, would it be possible to see your dissertation somewhere? thx

------
porker
It'd be interesting to know more about this approach. In particular:

> One big difference in Vicarious’s approach, says cofounder Dileep George, is
> that its system can be trained with moving images rather than only static
> ones.

Does this imply they teach it how the shapes of numbers change, for easier
detection?

~~~
waps
It generally means you teach it to recognize 3d shapes (a 2d image that moves
= a 3d image, more or less. Yes there's a good reason why you might want to
call it 2.5d, but the easy way to model a 2.5d object is in 3d). Think of it
as the difference between recognizing 2 points and recognizing a Feynman
diagram.

This is one of the things people don't often realize you can do with
algorithms. You don't need to look at the world the way it actually really
exists, and there may be very good reasons not to. Training algorithms to
actually recognize moving images is incredibly hard, because it requires
things like memory, fade-outs, recurrent networks, all that very advanced
stuff. Obviously time exists as a continuum in the "real" world. But that's
bloody inconvenient. So just look at big "quanta" of time, collecting all data
points during the quantum, analyse it, then shift the quanta/window ahead 0.1s
and do the exercise again. This is so much easier you wouldn't believe it.

Teaching an algorithm to recognize, say, a car collision, given 100 frames. It
doesn't require any change to the algorithm (just a change in training data).
And obviously your backend system needs to be aware that, over time, the
"isColliding" output will look like
......1.....11.....1111...1111.1.1.111.11..11...11.11...11...1.....1...1......
when a collision occurs and this of course doesn't mean you've had 20
collisions.

It does mean a bigger network, slower training, and more resources needed. But
not as much as you'd think. Keep in mind that a "temporal" network will need
more hidden layers. Also please consider building "redundant" networks for
temporal data. When people ask why, I have no better answer than that it's the
same technique our brain uses, so frankly if it's good enough for God, it's
good enough for me.

Doing the temporal thing means you're back to using trivially simple
algorithms, running on more data.

Cracking captcha's is not very impressive. I've done it as a weekend project,
and exceeding "average" human captcha'ing ability is easy. I actually got it
to the point where my algorithm was slightly better at captcha's than me,
where I was allowed to take 2 minutes for difficult captchas. If I wasn't
allowed to take more than 10 seconds, my algorithm easily beat me by over 10%
(my captcha performance, when measured, shockingly is only ~83%). I didn't
cheat : I used an external site's captchas (from dns.be).

The algorithm used was dead simple backpropagation.

~~~
alphydan
> Cracking captcha's is not very impressive. I've done it as a weekend
> project, and exceeding "average" human captcha'ing ability is easy

If it's so easy, could you share it on github?

------
theboss
I've Used a toolkit like 3 years ago that completely beat the captchas.
Recaptchas are harder though. Which did they beat?

~~~
welly
Both Captcha and Recaptcha failed terribly on a forum that I run. I run a
photography forum and what worked great for me was asking the user signing up
to answer a pretty simple question related to this fairly specific (large
format) kind of photography. I get no spammers or spambots at all now.

Turning on recaptcha only briefly to test resulted in a mass of spammers.

~~~
theboss
This is because you can pay to have humans resolve captchas. It is really sad,
but worth it I guess to the spammers....

------
gprasanth
Spam = Problem -> Captcha = Solution -> Captcha Solver = Another Problem.
Sigh.

~~~
svantana
Well if you read the article you'll see that it's only a technology demo,
they're not releasing it as a product and their goal is not this but computer
vision /brain mimicking in general.

Even CAPTCHA inventor Luis von Ahn has talked about CAPTCHAs being a practical
way of generating test data for computer vision systems.

------
acchow
I wonder how it does on reCAPTCHA

~~~
ozh
Probably better than me anyway: I usually refresh the reCaptcha image at least
10 times before I get one that 1) I _might_ decypher and 2) won't take 15
letters to input

------
EGreg
What if we will reach a time when robots have sex better than people... then
what will happen?

~~~
freehunter
The world will keep spinning?

I think the assumption you're making is that humans only have sex because it
feels good, and not for the explicit purpose or the creation of life. If
people want children, they'll procreate regardless, even if it doesn't feel as
good as robot sex.

------
b0z0
Not surprised. Not to be cavalier or anything, but I mean, even I was about to
start a side-project to solve those things.

~~~
GuiA
Awesome! It would be amazing if you open sourced your own solutions for it so
we could learn from you- I find the topic fascinating! :-)

~~~
boyter
Shameless plug [http://www.boyter.org/decoding-
captchas/](http://www.boyter.org/decoding-captchas/) I wrote this a few years
ago. Has full source code too.

