Alex Borisov

Personal Blog

reCaptcha implemented

August9

Quick post. Basically I’m getting tired of all the ‘nice post’, ‘interesting read’ yada yada posts that link back to pharmaceutical companies and people trying to sell placebo medication to people stupid and desperate enough to buy into that shit.

Even though akismet does a fantastic job, I still have to sift through this crap. So I’ve implemented a reCaptcha system on all comments and also all emails (both in posts and in comments) have been hidden via reCaptcha. If you don’t know how this works, it basically transforms exam...@example.com into ex….@example.com and you have to click on the dots and answer a quick reCaptcha in order to reveal the email.

It’s a small inconvenience (mostly because some times it’s hard to read the captcha and you have to keep clicking the little refresh button) but due to 90% of the worlds computer users being pretty stupid about stuff like security (and hence their machines are zombies in some botnet) i cant simply block all traffic from Nigeria, china and Russia (and it wouldn’t be nice for the 0.000001% of this sites viewers that are from those regions and are not spammers or bots). Plus the reCaptcha system actually is useful since it takes your responses and uses them to aid in recognition of unknown words that occur during the digitisation process of books (see http://recaptcha.net/learnmore.html)

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posted under News
7 Comments to

“reCaptcha implemented”

  1. On August 29th, 2009 at 2:09 pm Rob Evans Says:

    I developed a simple post system that makes the user select from 9 images in a block all the kittens (where the block shows kittens and puppies). Because the images are random and only the computer knows which image it served into what box, the code cannot be used to determine the type of image (images names in the HTML have nothing to do with the image being displayed as they simply count from 1.jpg to 9.jpg).

    No computer is even close to smart enough to pick the kittens from the puppies so it works really well, and it’s not annoying for users either, everyone loves kittens and puppies!!

    Also, I used GD to generate the images so that every time I add a new image to the list the system can use, I provide two bounding-box co-ordinates, one of the kitten or puppy location on the image, and the other is a box AROUND the image of the animal that the image producer script uses to move the image around a bit, so that even the image is random, that way even if an automated system “saw” every image generated, it still could not match it to one being displayed on screen because they are not pixel-perfect matches.

    :o )

    Rob

  2. On August 29th, 2009 at 2:13 pm masayume Says:

    That’s pretty smart. I love the idea. I might try coding one of those :D

  3. On August 29th, 2009 at 2:18 pm Rob Evans Says:

    I’m writing a wordpress plugin if you’re interested?

  4. On August 29th, 2009 at 2:24 pm masayume Says:

    Sure :P

  5. On June 1st, 2010 at 11:59 am nirmal m Says:

    I want to test your recaptcha

  6. On June 1st, 2010 at 12:00 pm nirmal m Says:

    am testing your recaptcha….why doesnt it verify the second word? :-(

  7. On June 1st, 2010 at 4:32 pm masayume Says:

    Click the link to the official recaptcha description. Basically only 1 word is used for captcha. The other is an unrecognised word during the OCR process of some book. The concept being that the user validates themselves with the first and helps out a better cause by recognising the second. Compared to humans, machines tend to suck at recognition. And they are cheaper ;)

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