[nfbcs] Captcha

Tue Feb 28 17:05:55 UTC 2012

Computers are better at arithmetic than people are. The only reason a simple 
arithmetic  problem works to keep out spammers is that its different. If a 
lot of sites did that, it would be ineffective. I haven't been to the 
Southwest Airlines site but assuming all you have to do is type in the 
answer to a simple arithmetic problem in addition to your name and password, 
it would take any good programmer just about 10 extra minutes to add that to 
their screen scraper program. So the spammers haven't taken the time to 
customize their spam bots for Soutwest Airlines yet.

Really, the whole captcha thing is like that. I doubt that writing code to 
break captchas is all that difficult. But spammers have a marked tendency to 
move on when faced with a little trouble. You don't have to make it very 
hard for them because there are lots of other places that don't make it hard 
at all.  There is a concept in email spam prevention called "grey listing". 
All it does is make the sender wait for a short period of time before trying 
again to send its mail.  Most dspam bots just move on w/o waiting. But if 
everybody used greylisting, they'd just adjust their bots.  Nothing could be 
simpler.  The only reasons they don't are that it would take a little longer 
to send each message and there are plenty of other fish in the sea.

I really think the only reason that captchas still work is that spammers 
haven't really turned their attention to breaking them yet.  First of all, 
it would take their bots a few milliseconds longer to break into each site. 
And besides, there are plenty of other fish in the sea.

----- Original Message ----- 
From: "Mike Freeman" <k7uij at panix.com>
To: "NFB in Computer Science Mailing List" <nfbcs at nfbnet.org>
Sent: Tuesday, February 28, 2012 10:22 AM
Subject: Re: [nfbcs] Captcha

> Delta Air's GogoInFlight wifi has you solve a simple math problem. This 
> would work for the deaf-blind though not for the cognitively-impaired. 
> Can't win 'em all!
>
> Mike Freeman
> sent via iPhone
>
>
> On Feb 28, 2012, at 8:03, "Tracy Carcione" <carcione at access.net> wrote:
>
>> In this case, "they" is Microsoft.  They are willing to listen to
>> suggestions, but no one knows how much work they're actually willing to
>> do. On the other hand, if they do listen, it could be great for many more
>> people than just my hospital.
>>
>> The only solution I've heard about that would work for deaf-blind people
>> is some kind of story problem.  I remember someone discussing that
>> here...John?
>>
>> Nancy,
>> You mean they show a picture of a bird, and play a bird sound?  If you
>> said cardinal instead of bird, would it still work? Interesting.
>> Tracy
>>
>>> Hello Tracy and everyone,
>>>
>>> Yup. God help any deaf-blind person who wants to access their medical
>>> records as they'll be locked out. They need to roll up their sleeves and
>>> find a non-captcha solution so all patients can have access to this part
>>> of
>>> their Web site. There are captcha alternatives out there. They need to
>>> find
>>> the one that will work best with their Web site framework and 
>>> development
>>> language. If the site is using ColdFusion they should check out
>>> CFFormProtect. This spam bot blocker takes the end user entirely out of
>>> the
>>> checking process. It does all of its work in the background and will
>>> resolve
>>> any accessibility issues disabled visitors may face when using this Web
>>> site. I'm using it on several of my Web sites and thus far have not had
>>> complaints about sites being spammed or individuals with particular
>>> disabilities such as hearing impairments being shut out.
>>>
>>> Peter Donahue
>>>
>>> ----- Original Message -----
>>> From: "Tracy Carcione" <carcione at access.net>
>>> To: <nfbcs at nfbnet.org>
>>> Sent: Tuesday, February 28, 2012 8:38 AM
>>> Subject: [nfbcs] Captcha
>>>
>>>
>>> The hospital I work for is creating a system where patients can see 
>>> their
>>> medical records online, and I volunteered to advise them on 
>>> accessibility,
>>> so far as I can.  The system is using a captcha during registration.  It
>>> has an audio version, but it's very hard to understand.  It took me 4
>>> tries to solve it, although it might have been easier if I'd had
>>> headphones on.
>>> Is that usual for audio captchas?  Can anyone give a site where captchas
>>> are particularly well-handled?
>>> Thanks.
>>> Tracy
>>>
>>>
>>>
>>>
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>>
>>
>>
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