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1. • CommentRowNumber1.
   • CommentAuthorAndrew Stacey
   • CommentTimeSep 25th 2012
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   Author: Andrew Stacey
   Format: MarkdownItexreCaptcha has been proving problematic of late (*\*grumble Google grumble\**) so I'd like to replace it. We should have *something* in its place. It's used in two places: when someone creates an account, and for "guest" posts in some categories (notably the "Latest Changes" category). The basic idea of a captcha is simple: it's a challenge-response where the challenge is such that an automated system is unlikely to be able to figure it out (this is no defence against a *targetted* attack, of course). As such, they aren't too hard to design. The difficulty is in getting enough entropy. One common version is to produce a degraded image with the text for the person to repeat. Another is to put a question that is easy for a person to comprehend but not for a computer. Some are using maths for this! Anyway, if anyone has any comments or suggestions while I try to figure out the best replacement, please let me know.

   reCaptcha has been proving problematic of late (*grumble Google grumble*) so I’d like to replace it. We should have something in its place. It’s used in two places: when someone creates an account, and for “guest” posts in some categories (notably the “Latest Changes” category).

   The basic idea of a captcha is simple: it’s a challenge-response where the challenge is such that an automated system is unlikely to be able to figure it out (this is no defence against a targetted attack, of course). As such, they aren’t too hard to design. The difficulty is in getting enough entropy. One common version is to produce a degraded image with the text for the person to repeat. Another is to put a question that is easy for a person to comprehend but not for a computer. Some are using maths for this!

   Anyway, if anyone has any comments or suggestions while I try to figure out the best replacement, please let me know.

2. • CommentRowNumber2.
   • CommentAuthorTobyBartels
   • CommentTimeSep 27th 2012
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   Author: TobyBartels
   Format: MarkdownItexSince the weakness in reCaptcha is in the audio version, there's no point in doing anything that isn't accessible to the blind, since otherwise we could just remove the audio from reCaptcha. >Some are using maths for this! That's because the question is easy for the computer to randomly design. But surely these are easy to crack too?

   Since the weakness in reCaptcha is in the audio version, there’s no point in doing anything that isn’t accessible to the blind, since otherwise we could just remove the audio from reCaptcha.

   Some are using maths for this!

   That’s because the question is easy for the computer to randomly design. But surely these are easy to crack too?

3. • CommentRowNumber3.
   • CommentAuthorAndrew Stacey
   • CommentTimeSep 28th 2012
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   Author: Andrew Stacey
   Format: MarkdownItexThe real problem with the reCaptcha is that it depends on an external site and for some reason that I don' t understand we've started having problems establishing a connection to it. So I've switched it off on the registration page. I would like to put something in its place but it's now switched to being actively a hindrance.

   The real problem with the reCaptcha is that it depends on an external site and for some reason that I don’ t understand we’ve started having problems establishing a connection to it.

   So I’ve switched it off on the registration page. I would like to put something in its place but it’s now switched to being actively a hindrance.

4. • CommentRowNumber4.
   • CommentAuthorUrs
   • CommentTimeSep 28th 2012
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   Author: Urs
   Format: MarkdownItexAh, I didn't earlier understand what the problem was (therefore that email which I had sent). I can't help with making suggestions for what might replace the reCaptcha. But maybe we just wait to see if it proves to be necessary to install another mechanism? Maybe it turns out not to be worh the trouble?

   Ah, I didn’t earlier understand what the problem was (therefore that email which I had sent).

   I can’t help with making suggestions for what might replace the reCaptcha. But maybe we just wait to see if it proves to be necessary to install another mechanism? Maybe it turns out not to be worh the trouble?

5. • CommentRowNumber5.
   • CommentAuthorTobyBartels
   • CommentTimeOct 1st 2012
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   Author: TobyBartels
   Format: MarkdownItexAh, I see.

   Ah, I see.