Slashdot Mirror
ReCAPTCHA.net Now Vulnerable to Algorithmic Attack
n3ond4x writes "reCAPTCHA.net algorithms have been developed to solve the current CAPTCHA at an efficacy of 30%. The algorithms were disclosed at DEFCON 18 over the weekend and have since been made available online. Also available is a video demonstration of random reCAPTCHA.net CAPTCHAs being subjected to the algorithms." There's probably an excellent Firefox plugin to render this page's color scheme more bearable. Note: the PowerPoint presentation linked opens fine in OpenOffice, and the video speaks for itself.
So what is the average human success rate? I think mine is only about 50%
Can these attack algorithms actually increase the accuracy of normal OCR programs?
I recently went to their homepage and looked _really_ hard for any statistics about which books are transcriped. I read their Science paper. Tried all sections.
Its all about the captcha part, and _nothing_ about the RE.
The way they state how it works ("We are using 100.000 unique words") sounds like they have given up on that part long ago and just recycle their old database again and again...
HI O WISE PRINCE. WHT TOOK U SO DAM LONG?
I'm watching the video, and the end result is "b:1/78 1.28% s:27/78 34.62%" indicating that out of 78 tests of two words per test it got a single word right 35% of the time, and both words right only once or 1% of the time.
Since both words need to be correct "solve the current CAPTCHA at an efficacy of 1%" would be closer to the truth.
No plugin needed:
View->Use Style->None
That is what it looks like in Seamonkey, Firefox will be similar. This more or less always works.
--frank[at]unternet.org
Should I run the DEFCON presenter's giant SWF or not?
o_O
Maw! Fire up the karma burner!
Why would anyone want to do this? It's like attacking the UN peace keeping troops or the Red Cross. reCAPTCHA is doing good work, digitizing scanned printed books so that the the text can be made available for online searching. Breaking reCAPTCHA is like defecating in the village well, ensuring that everyone suffers. No one benefits from reCAPTCHA being broken. No one.
Put my fist through my alarm clock with its ding-dong death inside my ear. - The Blackjacks.
"...an excellent Firefox plugin to render this page's color scheme more bearable."
Yep. Color Toggle
https://addons.mozilla.org/en-US/firefox/addon/9408/
I have it set so Ctl-Shift-Z set light yellow background, black text, and blue links.
No, Firefox addons used to be called extensions, plugins are still plugins.
Did you not learn when I explained this yesterday? The quote is: "My eyes! The goggles do nothing!". There is no "they", nor is there any bad pronunciation. Indeed, it is correctly articulated and enunciated, with an accent.
Easy there champ, nobody appreciates a Family Guy nerd correcting everyone's quotes.
<Complete your profile by adding a signature!>
Anybody that pays attention to 4chan recently knows they had to implement captcha due to a massive spamflood of infected morons. recaptcha got busted thanks to someone in /g/ who leaked the vulnerability in the sound system for reCAPTCHA, and the whole site was again inundated with spam, though not to the degree as the original spam attack.
Still waiting on Serviscope_minor to wake up to fucking reality and realize that Jessica Price isn't going to fuck him.
There is ZERO reason to use worthless tests like these as opposed to using real identification. That is instead of using computer generated difficult test, use actual pictures of actual 'difficult text' that an OCR agent failed to identify. Each person is given one alread tested sample and one unknown sample. If you get the already tested sample, then your answer is accepted as 'probable' correct for the unknown sample.
Congratulations, you've just described ReCAPTCHA! This is exactly how the current system works.
"The state is that great fiction by which everyone tries to live at the expense of everyone else." - Bastiat
Wrong. Plugins have been around since Netscape and are still called plugins. They have a different function than an extension (and an extension is what we would want in this case to fix the site's colours).
Both plugins and extensions, along with themes, are collectively referred to as "addons." "Plugin" is the wrong word in the summary. "Extension" or "addon" would have been acceptable.
When it is claimed to be 30% accurate, I'd expect some 30% of all captchas being correcly guessed. Watching the video, I noticed the algorithm gives itself 30-40% scores for getting just one of the two words right or sometimes even for getting the right length and a few correct letters. Didn't watch it to the end, but in the few minutes I watched, ZERO entire captcha's were solved. So that's ZERO% acurate in my book. For instance, actual captcha text "ware readiness", guessed captcha "votarry rehabbed", reported accuracy 38.24%... how the hell is that over 38% accurate? If you had that level of accuracy when trying to get past a captcha (which is pretty much the definition of it being vulnerable, right?), you wouldn't get past a single captcha. it's 30% accurate if it correcly guessed about 3 out of every 10 captcha's, not if it fails every single captcha.
Slashdot social media options: AIM, ICQ, Yahoo, Jabber and Mobile Text. Why no MySpace?
Judging from the other replies, meta-humor is a little hard for you guys...
It works wonders though. For instance, the next time someone is talking about "the force" or jedis and such, tell them "Get a life, Star Trek sucks!". You'll find the reaction much more interesting than if you correctly identify the franchise.
<Complete your profile by adding a signature!>
Seeing this article gave me an idea to come up with a new human verification process. I created a C# program in about an hour that loads images from Google images based on searching for 3 of 2000+ nouns. It shows 3 examples of each noun and asks the user to pick the correct noun from a list of 6. This program is just a proof of concept of course. Could this become useful? (Binary and source code included.)
http://enigmadream.com/misc/HumanVerification.zip
You know a hacker is hard core when his site is monochrome in a monospace font, and he saves his files as straight up docx.
You young ones and your complaining. "Ohhh the colors suck" SO WHAT! You don't remember when the Internet was invaded by those dual demons from hell, Geocities and Comet Cursors! Now THAT was torture buddy! YOU try dealing with a page that looks like it was designed by Unicorns on a crack binge, while having a fricking pocketwatch suddenly appear and hang from your cursor like a ball of snot on a string, all while having your shotgunned modems drug down to 300 baud land thanks to a bazillion puke inspiring GIFs spinning all out of time!
Now THAT is real suffering kid! /wanders off muttering/
ACs don't waste your time replying, your posts are never seen by me.