The Completely Automated Public Turing test to tell Computers and Humans Apart or CAPTCHA is a web based tool which is used to separate or define the difference between real users and automated users, such as bots. CAPTCHAs produce challenges that are difficult for computers to perform but relatively easy for human users.
How CAPTCHA Works
CAPTCHAs operate by providing information or a challenge to a user for them to complete. Traditional CAPTCHA tools provide a string of letters or numbers which a user needs to match and submit before they are able to complete or confirm an action on a website or app.
However, since CAPTCHA tools have been introduced and used, machine learning tools have been developed with increasing accuracy to identify characters and patterns which have allowed bots and tools to pass any CAPTCHA challenges. To protect against this, newer and more complex CAPTCHA methods and challenges have been developed.
How Is CAPTCHA Used
CAPTCHA tools are normally used within a website or web based app in order to restrict access or the completion of forms by non-human users, bots and automated tools. Some examples include:
Prevent False Comments
CAPTCHA tools can prevent automated tools or bots from spamming comment areas, contact forms, review or message sites. This can improve the overall quality and level of information within a site and also reduce the amount of resources which a website or web based app is using.
Online Polls
Using CAPTCHA tools within a poll can ensure that any poll's are completed by human users so that the results are not skewed. Where a CAPTCHA tool will be unable to limit the number of entries within a poll, to discourage multiple votes from single users, a time limit can be introduced instead. For example, 1 vote from a user every 5 hours.
Preventing Price & Quantity Manipulation
As well as being able to prevent the false or multiple registrations for free events, CAPTCHA can be used to limit the number of purchases which are made by a single user. This is helpful in the case of event ticket purchases to restrict scalpers from purchasing a large quantity of event tickets for resale.
Registration Limits
Web-based services which allow for the free registration to access products and services within an account can use CAPTCHA tools to prevent automated systems or bots from creating fake accounts.
There are various tools and services provided by companies such as Google which allow you to install and use CAPTCHA tools and services within your website or web-based app. Feel free to take a look at the following links which will provide further information about CAPTCHA and get in touch with the Digital Chimps if you wish to learn more.