ReCaptcha
In my ongoing fight against spam I have resorted to using captchas. Now, in one way, captchas generally do there job quite well, they are a big barrier to automated spam systems. However, they also act as a barrier to legitimate users, or just end up being fucking annoying.
The best solution in my opinion (since its the one I’m using xD), is reCaptcha. It uses words from books that failed OCR, so is unreadable by even the most sophisticated OCR tochnology (in theory). But, because it is words, it is inherently very readable by humans. Not only is it accurate and bearable, it is also helping to digitize the books the words are from (presumeably it must decide what the right answer is by taking a consensus).
Sooo, generally nice nice nice. I’m not sure why I haven’t tried it before now. Fingers crossed, and be sure to let me know if it breaks.
So, yeah, a little update from the Freedom Dreamer. There might be more posts coming soon, there might not.
Iestyn Pryce:
Although capchas such as reCapcha do seem quite usful in improving OCR and stopping spam, image based capchas are not very good for accessibility – screen readers cannot read images. In my opinion it is preferable to have some kind of maths based capcha such as “Put the answer of 3+45 in the box”, as this can be easier read by screen readers, and isn’t as problematic if you generally have bad eyes.
12 October 2008, 8:35 amBen Webb:
The problem with puzzles is that either 1) they are limited in number and can be cracked by brute force (what colour is snow) or 2) they can be parsed by a clever enough spam bot (3+45 would be easy to solve by computer).
However, reCaptcha offer an audio based captcha, which makes it quite accessible. I presume there is something handy in the alt text to tell screen reader users how to listen to this.
So, the number can do nethir type of captcha (quite blind and deaf) will be relatively small, and I’m not sure how they would be able to use my site anyway… except maybe braille displays. If there are any such users of my site, I guess they will have to ask someone else to fill in the captcha for them
.
So, basically, given the stuff above, Captchas aren’t perfect, will inevitabley alienate some users, but I feel reCaptcha gets the balance right – it is really hard for computers to crack but still has a fair degree of accessibility.
12 October 2008, 2:09 pmAnonymous:
spamspamspam
spams getting through your captcha!!
spam
lol
19 October 2008, 4:18 pmBen Webb:
Oh noes, there is the spams.
20 October 2008, 8:57 amMax:
I have never used ReCapatcha before because I always thought it was un-free by restricting modification in some way. Are you aware of what license it is under? I would really love to use this!
29 November 2008, 12:38 am