View Single Post
Old 07-23-2009, 11:29 PM   #1
joedevon
Enthusiast
joedevon has a complete set of Star Wars action figures.joedevon has a complete set of Star Wars action figures.joedevon has a complete set of Star Wars action figures.
 
Posts: 46
Karma: 274
Join Date: Jun 2009
Device: PRS-505
Oh no, watch out for P word in your e-texts via reCaptcha

Now this is weird (if it doesn't seem relevant, read to the end, and you'll see why I posted it):

http://stackoverflow.com/questions/4...efeated-broken
Quote:
Hacking Recaptcha (aka ‘The Penis Flood’)

The next tactic used was to see if they could find a flaw in the reCAPTCHA implementation. One thing they discovered about reCAPTCHA was that it always presents two words to a user for decoding - one word is a control word known by the reCAPTCHA system, while the other is an unknown word (reCAPTCHA uses the humans to help correct OCR errors). Wikipedia describes the process: “Scanned text is subjected to analysis by two different optical character recognition programs; in cases where the programs disagree, the questionable word is converted into a CAPTCHA. The word is displayed along with a control word already known and is labeled by the human. Those words that are consistently given a single label by human judges are recycled as control words”. 2iasdo4 What Anonymous realized was that if they always labeled the unknown scanned text with the same word - and if they did this thousands and thousands of times eventually a large percentage of the unknown words would be mislabeled with their word. All they had to do was look at the two words in the captcha, enter the proper label for the ‘easy’ one (presumably that would be the one that the two optical scanners would agree upon) and enter the word “penis” for the hard one. If they did this often enough, then soon a significant percentage of the images would be labeled as ‘penis’ and the ability to autovote would be restored (one side effect, that was not lost on Anonymous, was the notion that for years to come there would be a number of digital books with the word ‘penis’ randomly inserted throughout the text. Update: I asked Ben Maurer, chief engineer of reCAPTCHA about this ‘penis flood‘ attack, Ben says that they’ve anticipated this type of attack and they have numerous protections that will keep the penises from penetrating the reCAPTCHA barrier.
I was going to make the title of this post, "Watch out for Penises in your e-books", but then I thought besides getting the post yanked, I would be banned too.

Oh what a world we live in when we can't read our e-books penis-free due to ineffective anti-spam measures that make life difficult for the blind...

(heck I have trouble getting half of those captchas right myself)
joedevon is offline   Reply With Quote