The word captcha is not new to Internet users today. The full meaning of CAPTCHA consisting of English words – Completely Automated Public Turing test to tell Computers and Humans Apart. That is, captcha is the process of automatically verifying the difference between a human and a computer. Bot software has improved a lot with the advancement of technology. Cyber ​​attackers use these bots or scripts to extract information from various sites.

Captcha is linked to almost every site to prevent them and increase Internet security. Let’s take a look at the different types of captchas available on the Internet and the rules for filling them.

Text Captcha

It is possible for any human being to understand and fulfill it fairly easily. See the following example taken from the online portal of Bangladesh National Identity Card.

The box above the arrow in the picture contains a captcha. If you look closely, you will see kwnx4 written in English letters with another box below it. Write kwnx4 in that box. In this way, when the captcha is written in such a picture in front of you, you have to understand what is written in the picture and write it in the right place.

>> How to download National Identity Card online

General mathematical problems

Such Captcha It can be seen everywhere on the internet. In these cases a very common mathematical problem is given and it is asked to find the solution and give the answer. Problems are usually addition or subtraction. For example: “2 – 3 = how much?” Something like that. Anyone can fill out this type of captcha because it is so common. It is considered to be not very effective in maintaining the security of the website as it can be solved very easily.

Problems with words

In this type of capture, some letters or numbers, or both are given. From this, users have to type the mentioned words and numbers in the box next to them. The use of this word-related problem is increasingly noticeable on the Internet. No robot can easily solve such problems. So this method is considered to be much safer.

Social media sign-in

When creating an account on a website, instead of providing your personal information, you also have the option to sign in through social media websites. Many people use this type of sign-in system to save time. In this login system the information of the account created on that site is filled based on the information given in your social media account. However, it is better to stay away from such social media sign-in when creating an account on a relatively new website.

Time-based

Sometimes the form filling time is also used as a captcha. In this case, the completed form is considered to be canceled sooner or later. Usually a robot fills out the form instantly. This type of captcha is very effective in robot controlled sign-in processes.

Honeypot

Honeypot quite advanced captcha system. It provides some visible as well as invisible spaces on the site. When a person enters the site, they just fill in the blanks visible. However, when a bot enters the site, it fills in the visible as well as invisible spaces. This way the site’s captcha system can easily find the robot.

Picture identification

Picture identification can be understood from the name of the capture work. This type of captcha system provides different types of images and asks them to separate images with the same characteristics. Since the bot’s visual acuity is not so sharp, this type of captcha system takes full advantage of it by displaying a lot of low quality images. You do not have to enter any text in this type of captcha. Rather, they are said to distinguish certain objects or features from certain images. Failure to complete this captcha will result in multiple captchas being issued at once, which will take a lot of time to complete.

No captcha recapcha

Google came up with this captcha in 2014. Since its arrival it has been slowly gaining popularity. In this type of captcha system users have to click on a checkbox labeled ‘I’m not a robot’. In this system the movement of the user is generally considered. If a bot completes this captcha, it will click right in the middle of the checkbox, which is never possible with a human eye. However, once users fail to complete this type of captcha, any other type of captcha is provided.

Invisible recapcha

Invisible Recapcha The system is a relatively advanced captcha system. Invisible as its name implies. However, invisible recapture can be seen in one corner of a logo site. Capture does not exist on the website. It monitors how the user is using the site, how they are clicking on certain buttons. This type of captcha system is convenient for both the user and the site owner.

Confident recapcha

This type of captcha system allows you to distinguish an image with a specific theme from some images. About 98% of people pass this type of captcha very easily. However, those who are quick to use the website also fail to complete this simple captcha.

Suite Recapcha

This type of captcha is a lot like the confident recapture mentioned. In this type of captcha system some items are asked to be matched or sorted according to the movement. This type of captcha system is most effective. Bots can’t fill this type of captcha. Even people have to struggle to fill this type of captcha.

Which of the above captcha systems seems to be the safest for you? Let us know in the comments.