Arantor CAPTCHA

[Arantor]

Link to Mod

Description

While the default CAPTCHA used to be capable of warding many automated sign-ups and posts, user experience and reports suggest that it is overly obtrusive in style, making it harder for genuine users to post, which counters the principle behind CAPTCHAs that it should seek to minimise impact on genuine users.

Additionally, the lesser levels of complexity are mostly variations on a theme; randomised angles of letters, random colours and so on - ultimately a modestly advanced bot will be able to defeat it.

This module works by not just providing variations on a theme, but multiple varied distinctive styles of CAPTCHA, which differ compared to the classical styles and as such will likely need bots to become smarter in order to defeat them.

Each style has one or more additions that make it specifically irksome to automate, though no doubt some neural-network based bots will have some headstart on doing so.

It has also recently been noted that audio CAPTCHAs are far from invulnerable from defeat; this module offers the opportunity to disable the audio CAPTCHA for now, pending improvements to SMF's audio CAPTCHA system.


Styles

The styles provided by this version of ArantorCaptcha, in alphabetic order by internal module name:

• 'grid' - draw letters on a grid background
• 'ledicon' - draw letters as if they are lit bulbs on a board full of LED bulbs (like many automated marquee signs)
• 'recomposeanim' - have letters build up out of individual pixels randomly
• 'recomposecycleanim' - have letters build up out of individual pixels, and decompose back to nothing repeatedly
• 'recomposecycleanim2' - as above, but only to 40%-80% visibility, where a human could read the letters but a bot would have more difficulty
• 'shadowanim' - have just the shadows of letters build up out of individual pixels, with noise
• 'silhouette' - letters cut out of 'noise' background, using the effect of negative space to make the CAPTCHA visible
• 'simpleanim' - simple animation, revealing one letter per frame of animation; each letter appears after a slight delay
• 'stripes' - criss-crossed stripes, with letters cut out of one of the sets of stripes for the letter to appear out of negative space

Normal behaviour is for CAPTCHA images to be GIF images.


Changelog

1.0.8 - 22nd January 2014
! Removed 'initial' as it wouldn't work very well on some configurations
! After a long hiatus, updated for SMF 2.0.x including some minor bug fixes
- ArantorMods.com server long since offline
! This mod is now licensed under the CC0 licence

1.0.7 - 23rd August 2010
! Fixed support in German for non German users, thanks to Dismal Shadow

1.0.6 - 20th August 2010
+ Added support for German thanks to chilly

1.0.5 - 17th August 2010
! Removed ability for ArantorCaptcha to return to SMF's own style (previously a 1% chance of doing so)
+ Extra protection by default against spammers (the AC directory was not protected against people using a known list of files and checking to see what files were available, now it is, at least on Apache due to a sane .htaccess file)
+ Added 'stripes' style as suggested by Asgard
+ Added 'recomposecycleanim2' variation on recomposecycleanim; the changes in logic make it easier to keep separate (also suggested by Asgard)
! Non animated CAPTCHAs default to GIF now so that they don't immediately give away the fact they're different to bots
! Now supports ArantorMods.com's package server

1.0.4 - 13th August 2010
+ Added ability to disable some types of CAPTCHA
! Modified admin type override check to be more thorough (it is possible, if you are currently logged in as an admin, to force it to display a type of CAPTCHA; this is mostly for my debugging use)
+ More meaningful admin page
+ Added 'recomposecycleanim' style
! Tweaked 'ledicons' style letter R thanks to a suggestion from SleePy
+ Added 'shadowanim' style

1.0.3 - 8th August 2010
+ Added GIF animation class as a foundation
! Version numbers in XML files now only updated when the relevant files change (which is sort of how it was anyway; this is why only package-info.xml refers to 1.0.3)
+ Added 'simpleanim' style
+ Added 'recomposeanim' style

1.0.2 - 6th August 2010
+ Added 'grid' style
+ Added readme
+ Installer now redirects to the visual verification section of the Security/Anti-spam page in admin
+ Added option to disable the audio CAPTCHA
! 'ledicons' blue has changed in colour, orange added

1.0.1 - 26th June 2010
+ Added 'initials' style
! Internal restructure for efficiency and memory reasons

1.0 - 8th June 2010
+ First public release containing 'ledicons' and 'silhouette' styles


This mod is released under the CC0 licence

[live627]

Hey, nice to see this here.

[Arantor]

Yeah I was poking around in my archives looking for something and found this, so I dusted it off and published it.

[PhuriousGeorge]

Heh, my archives are a scary place. Can only imagine what goodies you have hidden in there.

[von COLLINZO]

This seems like a better replacement of the default smf captcha...I'll check this out.... Good job!

[bacanzito]

Thank you. 

[Biology Forums]

Very interesting. I noticed something like this on someone's forum a long time ago and thought it was cool.

[pierrelogic]

Taking it for a spin, thanks!

[kamili34]

Works great.

[Dzonny]

Got spammers even with this mod installed and with two verification questions. It's hard to stop those spamtards these days... :s

[margarett]

If you get human spammers, there's really not much you can do, other than react...

[Dzonny]

Yeah, that right, but I dunno if there's really tens of human spammers around this specific forum I've been trying this on. It's really not that popular forum, it's quite new so it's a bit weird, just saying

[butchs]

Nice job with the interesting php based CAPTCHA.

[alphacaveman2]

Hi, for some reason the images aren't showing up. Is there an extra step I'm supposed to take?

[Arantor]

Link to site?

[alphacaveman2]

It won't let me post a link, but if you go to GraceCentered dot com and go to the forum and click register you'll see. Thank you for your time.

[Arantor]

One or more of your PHP files is not starting with <?php and ending with ?> - but instead has spaces when it should not.

Take a look at http://wiki.simplemachines.org/smf/File_check.php_-_What_is_it_and_what_does_it_do - this tool will check your files for extra spaces.

[alphacaveman2]

Thanks very much! I'm going through correcting that. Thanks for your time/help.

[420Connect.co.uk]

Hey Pete,
Hope you're well

I'm wondering if I can disable the captcha required for sending PM's and only have it enabled for registrations..

Many thanks in advance

[Arantor]

That's actually an SMF setting, not one of this.

Have a look earlier up in the page for the minimum post counts. All this code does is replace SMF's CAPTCHA - if you were to uninstall this CAPTCHA at this point in time, you'd actually still have CAPTCHAs on PMs...