What's New in BotDetect CAPTCHA Version 2.0

Audio CAPTCHA Support

Besides CAPTCHA images, BotDetect 2.0 can now also generate CAPTCHA sound files for increased accessibility, thus making registration easier for the colorblind and people with otherwise impaired vision.

The sound file containing a spoken recording of the random CAPTCHA code can be accessed by clicking the speaker icon to the right of the usual CAPTCHA image.

Sound-enabled BotDetect CAPTCHA screenshot

When a user clicks the speaker icon, a CAPTCHA sound file is generated on the server and sent to the client without refreshing the page. If the client browser supports Javascript, the sound CAPTCHA playback is started immediately in the background. Otherwise, a download dialog is shown to the user.

50 CAPTCHA Rendering Algorithms

No single rendering algorithm is ever 100% unbreakable - but using multiple CAPTCHA algorithms can stop even the most determined attackers.

That's why BotDetect 2.0 comes with all the following CAPTCHA algorithms to choose from:

AncientMosaic

BlackOverlap

Bullets

Bullets2

CaughtInTheNet

CaughtInTheNet2

Chalkboard

Chess

Chess3D

Chipped

Circles

Collage

Corrosion

CrossShadow

CrossShadow2

Cut

BotDetect CAPTCHA Cut algorithm screenshot

Darts

Distortion

FingerPrints

Flash

Ghostly

Graffiti

Graffiti2

Halo

InBandages

Jail

Lego

Mass

MeltingHeat

Negative

Overlap

Overlap2

PaintMess

Rough

SpiderWeb

Split

Snow

Stitch

Strippy

SunAndWarmAir

SunRays

SunRays2

ThickThinLines

ThickThinLines2

ThinWavyLetters

Vertigo

WantedCircular

Wave

WavyChess

WavyColorLetters

Improved Security and Scalability

Since ASP.NET ViewState is no longer used to persist any information at all, BotDetect 2.0 ASP.NET CAPTCHA is now 100% safe from client-side ViewState tampering, resending, etc. This change is related to a previously reported issue.

Furthermore, the workflow used to generate random CAPTCHA codes, images and sound files has been improved for maximum resource conservation, ensuring that even the most traffic-heavy sites can benefit from CAPTCHA protection without notable performance impact.