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Subject: Re: human validation on post comments
Date: Tue, 21 Mar 2006 17:23:05 -0000
Message-ID: 
 <E7F85A1B5FF8D44C8A1AF6885BC9A0E4011C9697@ratbert.vale-housing.co.uk>
Thread-Topic: [pgsql-www] human validation on post comments
thread-index: AcZNCyJgIKLmt4FcR8q7N6fjcnlYKwAAG26w
From: "Dave Page" <dpage@vale-housing.co.uk>
To: "David Fetter" <david@fetter.org>
Cc: "PostgreSQL WWW" <pgsql-www@postgresql.org>

=20

> -----Original Message-----
> From: David Fetter [mailto:david@fetter.org]=20
> Sent: 21 March 2006 17:16
> To: Dave Page
> Cc: PostgreSQL WWW
> Subject: Re: [pgsql-www] human validation on post comments
>=20
> I see I didn't explain it well enough.  Here's the flow:
>=20
> 1.  Spammer generates spam and queues it up for sites.
> 2.  A person arrives at the porn site.
> 3.  The spam system generates a request including the spam to the
>     target site.  Clock starts ticking.
> 4.  The spam system presents the resulting capcha to the porn surfer.
>     Less than a second has elapsed.
> 5.  Porn surfer types in the string as asked.  Time elapsed is
>     probably still under 5 seconds.
> 6.  Spam system sends the string to the target site.  Time elapsed is
>     under 10 seconds for >90% of cases.

Ahh, gotcha.

>=20
> > > But apart from its ineffectiveness on spammers, as others have
> > > mentioned, capcha excludes blind people. :(
> >=20
> > Yes - it's a shame none of us thought about it when Gevik was
> > originally working on it.
> >=20
> > There is the audio option I suggested which Paypal use IIRC -
> > alternatively we could use some sort of puzzle - such as 'enter the
> > third, second from last and 2nd character from this string'.
>=20
> That lends itself to exactly the same attack I sketched out above.

Undoubtedley, but unless they write something specifically to work with
our site which is a lot of effort... And all we do then is fall back to
how things are now until we've broken whatever they were doing by
modifying the regexps in the auto-reject code or re-jigged the puzzles.
Of course, doing any of this we mustn't make it too difficult for the
user to submit things.

Regards, Dave.