How Hackers Listened Their Way Around Google's Recaptcha
An anonymous reader writes with this story at Ars Technica: "Three self-taught hackers from the DC949 hacker collective managed to use a combination of techniques to beat ReCaptcha with 99.1% accuracy (better than most humans!)" In short, the hackers skipped the visual part of the Recaptcha system entirely, focusing on the audio alternative, which gave them a few convenient angles of attack. Google responded with changes to the system, but that doesn't minimize their accomplishment.
Oh yeah! Not even a recaptcha to worry about!
They wisely chose the weakest link to attack.
Since they beat the Turing Test, this means we've reached the AI singularity... right?
There's no -1 for "I don't get it."
I realized there's an interesting aspect to this, in that gVoice transcription is actively trying to do basically the same thing these guys did* (albeit in a far more general way). Wonder how gVoice would do transcribing google's own recaptcha audio. Someone go try that. Either way though, it's an interesting dilemma if they ever got automatic transcription good enough to defeat these audio recaptchas.
* Well, after RTFA, I realize that a fair bit of what they did was actually more related to hashing (and the pseudo-random generator) vs actually trying to parse the audio, but still.
Most of the spammers who circumvent captcha's use real people to fill in their captcha's for them. How they do it:
1) A pay-per-filled-in-captcha site (where members solve captcha's, not really getting paid eventhough they think they will be) OR a high traffic site (false/scam sites, hacked sites, etc)
2) Mirror the image from the site you want to spam to your own site
3) A person visits your own site with the mirrored image and solves the captcha
4) Mirror the answer back to the site you want to spam
5) ???
6) Profit! (literally)
Every hacking group is now a hacker 'collective'?
That's it! Make all users do a SERIES of incredibly hard recaptchas. Those who get too many correct are machines! Brilliant!
I had one of these the other day that was beyond absurd. The visual was a complete scrambled mess, with nearly every letter seemingly equally likely too be 2 or 3 different letters. The audio was even worse: loud gibberish in the foreground with what sounded like someone whispering the actual text in the background. It wasn't until 2 reloads later that I was lucky enough to get a recaptcha that was only slightly ambiguous, and I was able to get it on the 2nd guess. I was far more annoyed at this than I ever have been at a spambot. I'm not sure this is a step in the right direction. Time to move away from garbled text.
Sometimes I wonder if the spambots would post better comments, though.
http://www.dc949.org/projects/stiltwalker/
Been waiting for this story to get picked up by Slashdot.
It EXACTLY minimizes their accomplishment. Everyone knew the day that was easily exploited, google would get a little less accessable to the disabled. Everyone knew it was the weakest attack point. (jerks!)
They get harder, and these days I'm four for five at best.
Maybe I'm just a machine dreaming I'm human?
Google's captchas are the worst I've ever seen. They're almost always unreadable and need to be refreshed all the time. I like Recaptcha (which isn't what Google uses on their sites despite owning it), they're generally pretty clear and in addition provide a free service to anyone that wants to use it. I have no clue why Google sticks with their awful in-house captchas for Gmail, Youtube, etc.
Google updated a few hours before these guys revealed their accomplishment. TFA mentions that other groups had found less effective ways of circumventing the audio portion. Is there any indication that this was about to be a problem? How likely is it that anyone wanting to actually abuse it was about to figure this out themselves? Seems to me like there are so many suckers out there, that spammers don't need to spend too much time with things like this.
Someone recently brought "AreYouAHuman" and its "PlayThru" security test to my attention.
http://areyouahuman.com/
I've been using Recaptcha on a niche website I operate for a couple years now, and people have been increasingly complaining about how hard it's getting. While it's English-only right now, PlayThru is very easy to complete, sorta fun, and best of all it tells you whether you got it right before you submit the form, so there's no hoping or guessing. So after a few quick tests, and users raving about how much better they like it, I switched today. The failure rate on security checks instantly dropped by 3/4 or better.
I wonder how long it will be before someone breaks PlayThru also. But until then, sorry Google but Recaptcha had to go.
I bet Siri could solve it.
All the voice tools out there could be harnessed to this sad end.
Truth is stranger than fiction, but it is because Fiction is obliged to stick to possibilities; Truth isn't. Mark Twain.
...to use the audio version instead of the text version for those damn things. I bet the audio version doesn't have words that show up with weird non-alphanumeric characters or completely inked-out text in them, like a nontrivial percentage of the recaptchas I see seem to have.
Providing the option of an audio captcha was a bad idea. Blind people are wasted on the internets anyway,
Rather a neat way to make an employment application.
The hackers toolkit must have had a much better voice recognition system than google's!!!
Anyone tried to use voice on google to do a websearch ?? It is the most inaccurate thing since we believed the moon was made out of cheese!!!
The results are most laughable..
Now *that's* impressive. The closest approximation I've heard to the audio captchas I've encountered would be the few recordings I've heard that John Lennon used to give out as gifts: he'd record multiple radios playing different stations.
I did once get an audio captcha that was almost solvable -- AFAICT, it was a conversation between C'thullu in his native tongue and Tom Waits responding in Aramaic, recorded in a crowded airport terminal that had lots of loudspeaker announcements.
reCAPTCHA was also undermined by its use of just 58 unique words
I'm really surprised the corpus was so small. Would have expected to be on the order of thousands.
Hey, Windows users, there is no such thing as "forward" slash, there is only slash and backslash.
That would work for an opening move but the whole point of chess is that there are many opening moves and with each additional move the possible moves explode until you need a very special sort of mind or a big computer (IBM big, not your pitiful 6 core big) to sort it all out.
How would your guy make sure the moves of the opposite player have any bearing on the moves on the other board? It would be like playing blackjack by copying what the guy next to you does. SMART, if by some miracle you had the same cards.
MMO Quests are like orgasms:
You may solo them, I prefer them in a group.
100% of press believes them 110%.
If you were blocking sigs, you wouldn't have to read this.
I've got a great new idea. If you can solve the Captcha, you're obviously not a human and are denied access.
I haven't seen an analogue to this idea outside the ColdFusion world, but CFFormProtect is an awesome tool for protecting ColdFusion-based sites from spam.
The basic idea behind CFFormProtect is that spam protection shouldn't involve annoying hurdles that users have to jump over, and should be as invisible as possible to the user. It takes what I would say is a similar approach to SpamAssassin, in that it uses multiple heuristic methods to rank form postings for potential spamminess. I've used it extensively and I've been really impressed with it. I'm not saying that it can't be defeated by a machine, but at least it doesn't annoy and flummox the site's users in the process.
www.clarke.ca
Yes, they should be awarded. Not for the whole "made in computer to beat computers" thing, but they actually helped in an unintended way - speech recognition. I see this kind of stuff easily joining Praat and software like that, helping linguists to mess with experimental data.
Well done, sirs.
Nerdy news for your nerdy needs? http://www.soylentnews.org Soylent News is people!