CAPTCHA: Definition, Types, & Functions in Security Systems

What is CAPTCHA? While browsing various websites online, you have undoubtedly been asked to complete a code called CAPTCHA.

Though it may sound quite common, do you really know about “what is CAPTCHA” as well as its types?

CAPTCHA stands for Completely Automated Publi Turing tests to tell Computers and Humans Apart.

Hence, differentiating between human users and computer systems is indeed one of the primary purposes of it.

To understand the definition, types, and functions more comprehensively, learn the following guide until the very end!

What Is CAPTCHA?

As a preliminary step, let's first understand “what is CAPTCHA”. As previously mentioned, it is a vital component in maintaining cyber security.

In this digital era, the interaction between humans and technology is becoming increasingly profound and comprehensive. 

Therefore, it serves as a security solution that plays a role in safeguarding websites or applications from potentially harmful activities that could be carried out by bots.

This security system performs its task by conducting a simple intelligence test to differentiate between humans and machines.

The authentication process typically involves the use of specialized designs in the validation process. Overall it was designed in such a way that only humans can complete it.

This is intended to filter visits to a website and ensure that the visits do not originate from automated systems by robots.

Furthermore, this security system is often implemented to prevent spam caused by irresponsible cybercriminal activities.

CAPTCHA Functions

While the task's completion may occasionally demand time, it remains imperative to underscore the significance of it, particularly for website proprietors.

Several primary roles of this security system are:

1. Preventing Dictionary Attacks on Website Pages

In general, this type of Dictionary Attack is carried out by hackers attempting to break the security code of an authentication system.

In this kind of attack, hackers typically input words or phrases listed in a dictionary within a hundred or thousand trial attempts.

2. Enhancing Security for Online Transactions

CAPTCHA is a security option that is often utilized to secure the website of an online store.

Store owners use it to ensure that transactions are carried out directly by humans and not by robots.

This function can reduce the possibility of fake sales where products appear to be sold, but the transactions do not actually take place.

Furthermore, the presence of this security system can also enhance the level of trust for potential customers and improve the user experience on a web page. 

3. Preventing Fake Account Registrations

Recently, several platforms have enabled users to freely create accounts.

In this scenario, CAPTCHA code serves as a filter, guarding against the misuse of data by unscrupulous entities through automated scripts.

Moreover, the presence of fraudulent accounts can detrimentally affect your digital marketing endeavors.

For example, an overwhelming influx of bogus accounts linked to email addresses could impede the successful execution of your email marketing campaigns, consequently diluting the precision of your strategy. 

4. Preventing Spam

Have you ever encountered CAPTCHA code when attempting to post a comment on an online site?

As one of the most applicable security features, it can also be implemented in the comment section of websites or blogs.

Since some activities in the comment section are often abused, it serves as an additional security layer to restrict repetitive and bothersome comments.

Comment spam is typically aimed at rapidly boosting ratings. Unfortunately, search engines like Google view such activities as a detrimental practice to be avoided. 

5. Adding Protection for Email Addresses

This security system also offers additional protection for email addresses to prevent scraping.

Do you know what scraping is? Generally, scraping is a security threat that can jeopardize your email.

Scrapers typically take the form of bots with the potential to "steal" and export data from a website. In more severe cases, scrapers can even take over ownership of a website.

This is why it is crucial to safeguard emails from falling into the traps of scrapers.

In addition to the above primary functions, this type of security system also plays a significant role, such as:

• Prevent bots from sabotaging the completion of forms or specific votes.
• Prevent mass purchases online to gain excessive profits in the future.
• Prevent hacking attempts through repeated password trials.

Types of CAPTCHA

After understanding what it is, let's get to know its general types. Here are some types of it that can be used as security authentication options. 

1. Picture Recognition 

Picture recognition is actually one of the most commonly applied CAPTCHA types.

Just as the name suggests, in picture recognition, visitors will be asked to scan pieces of images and perform actions according to the displayed instructions.

The displayed images are usually quite diverse, ranging from landscapes, traffic signs, vehicles, and graphical elements. 

2. Text-Based

This text-based is one of the six most commonly encountered types. As a text-oriented option, it encompasses an array of irregular codes. Visitors to websites are often prompted to reenter the code they see.

The code's arrangement is devoid of any discernible pattern, ensuring a high degree of randomness. It may comprise permutations of numbers, symbols, capital letters, and lowercase letters.

Various methods for generating the text type involve:

• Gimpy: Composed of irregular words and often overlaid with a transparent image.
• Gimpy-r: Comprises scrambled letters against a background image, creating a slightly confusing appearance.
• EZ-Gimpy: A variation of Gimpy, consisting of only one word. 
• Simard’s HIP: Comprised of random numbers and letters with additional color patterns. 

3. Math

Have you ever heard about this type before? In this security system, visitors are presented with a simple mathematical problem that needs to be solved. Usually, these math problems involve adding or subtracting two numbers.

4. Audio 

Audio type is commonly used on websites catering to visitors who are visually impaired or have visual impairments.

This type basically employs sound to dictate a code or password for authentication. Have you encountered this type before?

5. jQuery Slider

jQuery Slider is an authentication type that employs a slider. As a result, visitors to websites or blogs are generally asked to move an element using a cursor to complete the authentication.

jQuery types often come in the form of puzzles, requiring you to slide them into the appropriate position. 

6. No CAPTCHA ReCAPTCHA

Now let's learn about the easiest authentication process within this security system. In this type, visitors simply need to check the "I'm not a robot" box, and the authentication process will conclude automatically.

Although very easy for humans, in reality, this type is the most difficult for bots to bypass. Google's ReCAPTCHA typically consists of two dataset options:

• Google ReCaptcha v2: Presents a checkbox "I'm not a robot" for visitors to check.
• Google ReCaptcha V3: Has a simpler process with automatic security verification. This type directly scans the visitor's activity history.

CAPTCHA Limitations

Now that you know the definition, functions, and types. However, does this security protection have any drawbacks?

When assessed for its presence, this security system is also considered to have some limitations, such as:

• It has the potential to consume time, especially when visitors are trying to quickly access a website page.
• The presence of bugs in it can cause correct visitor responses to be marked as incorrect.
• It may potentially consume more internet data than usual, especially when loading problems involving images or audio.
• It could lead to reduced visits to e-commerce platforms.

That concludes the discussion on the definition, types, and general functions of CAPTCHA.

Now that you've learned about it, have you realized the importance of implementing this security system to enhance website performance?

In addition to incorporating security components, website optimization should also be complemented with SEO to ensure a comfortable, secure, and easily navigable user interface.

Therefore, aside from ensuring your website's security, you should also consider various aspects such as domain authority and search intent to create content that secures top rankings on the SERP.

Beyond boosting your website's rankings, an SEO strategy with professional assistance can also enhance the online visibility and customer trust for the products or services you offer.

If you encounter difficulties in devising the right optimization strategy, you can utilize SEO services by cmlabs to receive aid from Professional SEO strategists, who are available at cmlabs to help you achieve your desired business goals through SEO.