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CAPTCHA's Role in Cybersecurity

Updated: May 23

CAPTCHA's Role in Cybersecurity

CAPTCHA is a cyber security system that often appears when accessing a website. You will be asked to answer questions, or a puzzle on a website. Sometimes this is annoying, especially if you must do it repeatedly.

What exactly is a CAPTCHA?

Is it really necessary and safe? What is the real purpose of a CAPTCHA?

In this article, we will discuss more about CAPTCHAs and their role in Cybersecurity.

What is CAPTCHA?

CAPTCHA stands for “Completely Automated Public Turing Test to Tell Computers and Humans Apart” In short, CAPTCHA is a test to differentiate whether access to online requests on a website is done by humans or machines (robots).

CAPTCHA evolved from a Turing Test created by Alan Turing, a mathematician, computer scientist, and philosopher dubbed "the father of modern computing," in 1950. The Turing Test is a simple test with a few questions given to humans and machines, to test the intelligence of machines and distinguish between genuine human and machine answers.

It can be said that CAPTCHA is a form of modern turing test technology developed to increase the security of sites from cyber attacks. CAPTCHA technology began to be used in 2000 at Carnegie Mellon University and continues to be developed today.

What is Captcha Cybersecurity

The main function of CAPTCHAs is to provide a challenge and response that is easy for humans to do, but difficult for machines or robots to solve.

This is because machines use a special coding language that is different from human language, making it difficult to identify human language without being programmed first. CAPTCHA verification usually uses graphics in the form of letters, numbers, or images.

CAPTCHA's Role in Cybersecurity

CAPTCHAs play an important role in cybersecurity by providing a simple mechanism to distinguish between human users and automated bots or scripts. They are commonly used to prevent various forms of online abuse and exploitation. The following are some of the key roles of CAPTCHAs in cybersecurity:

1. Preventing Comment Spam:

Websites, especially blogs, and forums, use CAPTCHAs to prevent automated spam bots from posting unwanted content or comments. By requiring users to solve the CAPTCHA before posting, they can ensure that only humans can submit comments.

2. Protecting Website Registration:

CAPTCHAs are often used on registration forms to prevent automated scripts from creating fake accounts. This is especially important for online services that may be prone to fraudulent or abusive behaviour.

3. Prevent Ticket Scalping:

Online ticketing platforms often use CAPTCHAs to prevent bots from buying tickets in bulk for resale at high prices. By ensuring that tickets are sold to real humans, CAPTCHAs help keep ticket prices reasonable and accessible.

4. Protecting Email Accounts:

Many email service providers use CAPTCHAs to prevent bots from creating large numbers of email accounts, which can be used to send spam or other malicious activities.

5. Prevent Brute-Force Attacks:

By integrating CAPTCHAs into login forms, websites can add an additional layer of security that prevents bots from performing brute-force attacks, where attackers try to guess a user's password through quick, repetitive attempts.

6. Thwarting Web Scraping:

Websites can use CAPTCHAs to prevent automated scripts from scraping content or data, ensuring that proprietary or sensitive information remains protected.

Types of CAPTCHAs


Captcha Text cybersecurity

Text CAPTCHAs are the simplest. You must have encountered them on the Internet too.

This type of CAPTCHA is an arrangement of random combinations of numbers, letters, and symbols against a background of vague abstract images. The user must enter or retype the combinations in the specified order.

2. Picture recognition CAPTCHA

Picture recognition captcha cybersecurity

Picture recognition CAPTCHA displays pieces of images such as graphic elements, scenes, etc. The user must select the part of the image that matches the given conditions.

For example, the CAPTCHA tells you to select the part of the photo where there is a crosswalk

All you have to do is select the boxes and click "next" to proceed or "skip" if there is none in the photo.

3. Maths CAPTCHA

Maths captcha cybersecurity