Captcha Cracking Javascript

Spammers trick others into doing the CAPTCHA for them. Basically, spammers set up a warez site or a porn site that appears to have a CAPTCHA on it, but it's not a real CAPTCHA. A bot pulls the CAPTCHA from the site they want to spam (or otherwise exploit), and then displays it on the warez site or a porn site where someone completes it for them. 21 Free CAPTCHA Sources Here is a collection of free CAPTCHA scripts and services than you can easily integrate into your website using PHP or JavaScript: 1. Personally, if I was a spammer, I’d be comforted by the knowledge that my CAPTCHA crackers were adorned in jacket and tie and overseen by an attractive supervisor in a pants suit. But I digress. I thought it would be interesting to actually take up this service and see just how efficient outsourced CAPTCHA cracking can be.

Captcha Cracking Javascript Code

8 Oct 2009CPOL

Captcha Cracking Javascript Code

Introduction

This Particular article helps you in implementing Captcha in you webpage / website or in an application. Helps you in understanding and logical implentation of captcha on entirely client side.

Most of the websites use the technique of captcha for validation / verification purpose whenever someone tries accomplish membership or want to submit a piece of information. The generation of captcha can be done in various ways. We can use server side scripting or even we can use client side scripting.

Background

In most of the cases some times it happens that we need to have some additional resources / dlls to be registered on the hosting server in order to implement the captcha basically this happens in case of server side scripting.Here I have implemented the Captcha functionality purely on the client side using javascript.

Using the code

Generating Captcha using client side scripting is quite a simple but make sure that the javascript is enabled. Ya now a days almost all of the browsers supports the javascript. Anyways lets move towards the code details. the source code is quite simple and straight forwad. Just copy and paste the below mentioned code in blank html page and save it as whatever you like. download / copy an image and put in under same folder or at same location where the HTML file is created. The black angels phosphene dream free download.

Source Code

How does it works..

<input type='button' value='Check'/>

Onclick Event of button we are invoking the ValidCaptcha() method. Which in turns returns an boolean value i.e. True/False.

ValidCaptcha() Method compare's the entered code in the text box aganist the drawn or displayed code in the captcha box. RemoveSpaces(string) Method repoves the occurance of any blank spaces within the created as well as entered code. After all the both the strings are compared by removing any blank spaces.

Based on the return value fron ValidCaptcha the result is displayed as either 'True' or 'False'. you can customize the return value to any user friendly message instead of true or false.

<input type='button' value='Refresh' />

DrawCaptcha() Method is invoked to draw an captcha on the screen. On Click of refresh button we can generate/draw the new captcha images.

<body onload='DrawCaptcha();'>

On body load I am calling DrawCaptcha() method so that whenever the page is loaded the default captcha should be drawn.

Here we go, Save the HTML page and open in the web browser (IE/FF etc). Happy Coding....:)