#39688 [Opn->Bgs]: CAPTCHA threshold is way too high
| From: | bjori@php.net | Date: | Sun, 07 Jan 2007 18:45:12 +0000 |
| Subject: | #39688 [Opn->Bgs]: CAPTCHA threshold is way too high | ||
| References: | 1 | Groups: | php.mirrors |
| Request: | Send a blank email to php-mirrors+get-33733@lists.php.net to get a copy of this message | ||
ID: 39688
Updated by: bjori@php.net
Reported By: codeslinger at compsalot dot com
-Status: Open
+Status: Bogus
Bug Type: Website problem
Operating System: Any
PHP Version: Irrelevant
New Comment:
Please do not submit the same bug more than once. An existing
bug report already describes this very problem. Even if you feel
that your issue is somewhat different, the resolution is likely
to be the same.
Thank you for your interest in PHP.
Dupe of bug#37104
Previous Comments:
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[2006-12-01 17:03:50] codeslinger at compsalot dot com
The PHP Manual/User Notes section of this website is using a CAPTCHA
that works very well. It is text based and knowledge based. "What is
min(eight,three)?"
Why don't you just grab that code and stick it in here?
I am guessing that this would require changing exactly one line of
code? "generate_captcha();"
----------------------------------------------
P.S. I figured out what happened to my OXLW
attempt and why my message got thrown away, ouch!
What you don't make clear to people is that if they are the author of
the bug they MUST use "Edit" they MUST NOT use "Add Comment".
The response of the bug reporting program when an author tries to "Add
Comment" is that it allows the comment to be entered and then throws
away the entry and redirects to the password prompt. This is a very
"Hostile" action toward the hapless user. The only way that this would
be acceptable is if the bug program retains the comment that the person
entered and stuffs it into the comment box on the redirected form
entry.
------------------
I entered another bug today and scored 2 successful CAPTCHAs out of 5
attempts plus a 6th CAPTCHA image that I did not attempt because I was
certain of failure.
On a properly designed CAPTCHA, a reasonably skilled human should be
able to score a 98% success rate, NOT a 70% failure rate.
---------------
Security is a good thing, but too much security is a bad thing. A door
which is welded shut provides a very high level of security however it
is not a useful level of security for something that is intended to be
accessible.
------------------------------------------------------------------------
[2006-11-30 01:38:25] judas dot iscariote at gmail dot com
Yes, the captcha on this bugtracker is horrible.. I hope someone has
time to look into this...
------------------------------------------------------------------------
[2006-11-29 22:47:49] codeslinger at compsalot dot com
It took me 5 (3+2) trys to get past that CAPTCHA
And I was giving it my full attention and trying really hard to
decipher it.
Again I ask the question, what is the goal?
Why don't you just shutdown this website altogether?
..............
I am now looking at another CAPTCHA and trying to figure out if it is
an "O" or a "C", due to the way the line intersects, this is uncertain,
there is a gap in the line that you would expect for a "C" but it's not
really wide enough, so is probably a drawing artifact. It is also very
uncertain if it should be in lowercase, the "o/c" is about half the size
of the "X". But I am guessing that all letters to this program are
uppercase.
For what's it worth, I have saved a copy of all of these images, but
see no provision for attachments.
Trying: OXLW
=================================
I entered the above comment and submitted it, and it just totally
disappeared; no error message about a bad CAPTCHA or anything. It's a
good thing that I saved a copy of that comment first or I would be
extremely unhappy right now and having lost what I had typed. I have
no clue what happened to that comment or why it disappeared. But
probably it did not like the guess that I made for the CAPTCHA value.
Seems to me that this is a seriously buggy, bug reporting system.
------------------------------------------------------------------------
[2006-11-29 22:01:09] codeslinger at compsalot dot com
Description:
------------
There are multiple problems of the CAPTCHA system that require a
substantial redesign.
The CAPTCHA image is far too difficult to interpret.
If cookies are not enabled the CAPTCHA image is not visible.
The current implementation is in violation of the
"Americans with Disabilities Act".
etc.
Reproduce code:
---------------
in bug http://bugs.php.net/bug.php?id=33247:
wez@php.net says:
"Look, it was illegible about 45% of the time. There certainly is a
problem; it rejected my entries twice tonight (out of 6 page
loads)--and
the text I entered did match what appeared to be on the captcha."
That comment was from over a year ago, today my experience was much
worse, it took me at least six tries to get one success. That bug
(33247) was closed but the problem is not fixed yet, or perhaps it has
regressed to a previous bad design? (since I don't appear to be able to
reactivate it, I am entering this as new bug).
It was exceedingly frustrating to get past the CAPTCHA earlier today
while entering a bug/Feature Request, and required many many attempts.
I have experienced a lot of these CAPTCHAs on different web sites and
this one is by far the worst I have ever had to deal with. I looked at
it carefully and was sure that I was entering the correct text, and
again and again it was rejected. And I am not an unsophisticated
user.
It's not even clear how many letters are needed, mostly it seems to be
four letters, but then when nothing else worked I ignored the squiggle
that looked very much like the letter "L" and entered only three
letters, which to my surprise was accepted. Now how the heck am I
supposed to tell the difference between an "L" and a squiggle, when the
system is in fact designed to make "L"'s look like squiggle's? And
especially when I am expecting that it wants four letters when in fact
it only wanted three that time, but later it did want four letters.
Yes, the problem with spammers is a very bad one, and I can certainly
appreciate that you are feeling a little bit burned out on the endless
battle against both spammers and poor bug entries. But since when does
that justify changing the website design to be intensely user hostile?
There are quite a few bugs in the database, all saying the same thing,
this CAPTCHA is unusable. And all receiving the same response "Bogus"
or "Irrelevant"; with the exception of this one lone bug which is
claimed to be fixed, but most certainly it is not.
-----------------------
in bug: http://bugs.php.net/bug.php?id=33247 wez
says:
"The lines are too overbearing to the point where I'm unsure if I
should be entering U's or J's."
I agree with this assessment and would would further point out that,
the way that the colors are used is incompatible with people who are
color blind.
With regard to the oft repeated and cavalier advice that a person only
needs to "refresh" their browser in order to get a new CAPTCHA; this
advice ignores the fact that a browser "refresh" will throw away all of
the form data which has been entered. Therefore "refresh" is not a
valid action; at least not if you have any concern at all for the
effort of the people who are trying to use your system.
And then there is the tedious issue that being validated once is not
enough, if you have made a mistake which needs to be corrected such as
trying to specify "Irrelevant" for the build version, then you must
pass the CAPTCHA all over again. I would expect that once I have
successfully proven that I am a human, that I would be allowed to
remain a human :-) for at least 10 minutes before being again
challenged.
----------------------------------
in bug: http://bugs.php.net/bug.php?id=33247
dufuz@php.net says:
"I see no reason to lower the fuzziness when you can get a very
readable captcha [by doing retrys]"
I think there is a fundamental misunderstanding here of what the goal
is for a CAPTCHA program. The goal should be to prevent spammers from
using automated methods to post messages. Nothing more and nothing
less. The program therefore needs to be designed such that it achieves
the goal of preventing spammers, while at the same time placing the
minimal burden necessary upon the legitimate users of the system. This
CAPTCHA design does not meet that need, it does not fulfill that
requirement; this CAPTCHA as currently implemented places a huge burden
upon the legitimate users.
The question which should be asked when considering the design of this
CAPTCHA program is: Has it been demonstrated that any spammers are
using any type of pattern recognition system whatsoever? And if so
(which it hasn't been), what is the *minimum* level of
complexity/fuzziness of the image that is needed to ensure that
automated spammers do not gain access, while at the same time ensuring
ease of access for the legitimate user?
Yes it is true, that bright people at MIT and other places have created
image recognition systems which are truly quite remarkable in their
abilities. But as a practical matter, no spammer that I am aware of,
has deployed any such system and furthermore the compute resources
required to do this on a large-scale are prohibitive.
On the other hand, what I have seen instead, in one specific instance;
is where a spammer had hired a crew of -- undoubtably low-paid, barely
literate workers, to sit there in front of a computer and enter comment
spam into a forum. (see also www.amazon.com's experiment with the
"Mechanical Turk"). So you see, you really cannot win this battle by
CAPTCHA alone no matter how difficult you make it. But you can
certainly generate a lot of ill will and alienation of potential
contributors, in the process of trying to protect your web site.
in bug: http://bugs.php.net/bug.php?id=33449
sniper@php.net says:
"This way we get only reports which are real reports. :)"
There are better ways to achieve this result, ways that do not involve
alienating people. If it is such a huge problem, why not switch to a
fully validated registration system? Currently user notes posted to
the manual pages go through a moderation process before becoming
visible; clearly this takes extra work, but it is what PHP.net has
decided to do. Since the bugs must be reviewed anyway, it does not
involve any extra work at all to subject them to a similar moderation
process.
If the goal is to prequalify the person entering the bug; perhaps a
much more useful approach, would be to ask some knowledge based
questions about the PHP language, this at least would be a relevant
criteria and would probably also succeed in eliminating the
semi-literate "Mechanical Turk". But if you are going to do this, you
ought to do it before you allow people to type in the bug report. It
is very discourteous to allow someone to go to all the work of entering
a bug report and then reject that entry because they did not pass some
test. The test should be given first.
----------------------------------
And then there is the issue of blind people. Standards compliant
CAPTCHAs support audio or use a simple question and answer format such
as "What is two plus 3?".
Making public websites be accessible, isn't just something that is nice
to do, it also happens to be the law! And if you wish to be excused
from compliance then you had better be prepared with solid
justifications for your design decisions (exceptions are made but must
be justifiable). See the "Americans with Disabilities Act" for more
information.
In bug http://bugs.php.net/bug.php?id=37104
David Spector
Has generously offered to assist you with this task. And he appears to
be well-qualified to help you with this. Such offers of help should not
be disregarded casually.
David Spector
Webmaster,
Massachusetts ***Alliance of Visually Impaired*** Students
--------------------------------
And then there is the mystery of various people not being able to view
the CAPTCHA image on their browser, see for instance these bugs: (which
were marked bogus or otherwise ignored)
http://bugs.php.net/bug.php?id=32831
http://bugs.php.net/bug.php?id=36717
http://bugs.php.net/bug.php?id=33101
And then in this bug (which has also been ignored AFAICS) the answer to
the mystery is revealed:
http://bugs.php.net/bug.php?id=37170 sd at
sven-drieling dot de
says:
"CAPTCHAs requires enabled cookies to report bugs but no warning is
shown
if cookies are disabled. Without cookies the CAPTCHA image is empty."
--------------------------------
http://bugs.php.net/bug.php?id=33247
As a separate issue: Other people/bugs have commented on the fact that
you are forced to specify a PHP build number. And they were told that
this was not the case, however when I tried to enter a bug/Feature
Request, this is exactly what I experienced. Although there is a build
option to specify "Irrelevant", when you select this value, it is in
fact rejected and you are then forced to choose a different value and
you must once again fight with the CAPTCHA.
----------------------------------
Expected result:
----------------
All in all, PHP is a fabulous language, and the web site is exceedingly
well done. But this problem with CAPTCHA is pretty big in its potential
to alienate. And it puts up a substantial barrier to people who are
trying to make a contribution.
The excellence of the PHP language and the PHP web site, provide ample
proof that you people know a lot about good design. But this CAPTCHA
program, as currently implemented, is the antithesis of good design.
Actual result:
--------------
Endless battles with CAPTCHA verification
I'm looking at the CAPTCHA for this bug entry right now and I cannot
tell if that letter is supposed to be a mangled "I" or a "T". or
should I be ignoring that line and entering the "J" which is merged
with the "G" ?
I shall make a guess and see what happens, but it is totally ambiguous
and not at all reasonable.
I have saved a copy of this picture, if this bug supports attachments I
will add it.
......................
Well, I guessed HIVG and was rejected: trying again.
Guessing NHN but it probably is NTHN
Trying MABY - this at least looks readable
.....
Oh yipee, it liked that, but now I get to do it again. To confirm my
report.
.....
Trying UVPV -- but that last V could also be a truncated Y or is it a
lower case "v" is this thing case sensitive? with rare exceptions all
of the letters I have seen from it appear to be upper case....
......
Trying YJUD -- but is that a lower case "u"? can't tell, it is
slightly smaller than the "D" but not by much.
------------------------------------------------------------------------
--
Edit this bug report at http://bugs.php.net/?id=39688&edit=1