Websites use a captcha test to prevent bots from entering and disrupting their work. Captchas are tests that are easy for humans to answer, but robots have trouble answering them. In the following, we will define what captcha is and give important points about it.
What is CAPTCHA?
Captcha stands for Completely Automated Public Turing test to tell Computers and Humans Apart. Captcha is a security measure known as an authentication test. Users usually encounter CAPTCHA and reCAPTCHA tests on the Internet, which are one of the ways to manage the activity of robots.
In this method, a simple test is performed, by answering which you prove that you are a human who intends to log into your account, and it prevents any computer from accessing your account. A CAPTCHA test consists of two simple parts: a sequence of randomly generated letters or numbers that appear as a distorted image.
Next to them is a text box. To pass the test and prove your human identity, you simply need to type the characters you see in the image into the text box.
What is rikpcha?
reCAPTCHA is a free service offered by Google as an alternative to traditional captchas. Recaptcha technology was developed by Carnegie Mellon University researchers and then bought by Google in 2009.
Recaptcha is more advanced than regular captcha tests. Like CAPTCHA, this type of test requires users to enter images of text that computers have trouble deciphering. But unlike regular captchas, reCAPTCHA generates text from real-world images. For example, images of street addresses, text from printed books, text from old newspapers, etc.
Over time, Google has expanded the functionality of RecCaptcha tests so that they no longer have to rely on the old style of identifying garbled or garbled text.
What are the uses of captcha?
Now that we are familiar with the definition of captcha, we should see what is the use of captcha? Such tests are very common in login forms, account registration forms, online surveys, and e-commerce checkout pages.
On most sites, there are sections that allow you to register, fill out a contact form, or enter comments. Each of these pages allows users to interact with the site, but there is no guarantee that a bot will not do so.
The most common case where having a CAPTCHA code is useful is when you want to prevent bots from posting spam comments.
By using these tests, it is possible to prevent useless comments from being registered on the site, and only the real opinions of people are registered on the site. Online forms are sometimes placed on websites that use captchas to prevent unnecessary clicks and filling by bots.
How does captcha work?
Classic captchas used on some websites today involve asking users to identify letters. Distorted letters are placed on the site in such a way that they cannot be recognized by robots.
To pass the test, users must decipher the garbled text, type the correct letters into the form field, and submit the form. If the letters do not match, users are prompted to try again.
The idea behind this test is that a computer program such as a robot is unable to interpret distorted letters, whereas a human who is used to seeing and interpreting letters in a variety of contexts—different fonts, different handwritings, etc.—can usually do so easily. and recognizes them.
The best most bots can do is randomly input letters that are statistically unlikely to pass the test. Therefore, bots fail the test and are blocked from interacting with the website or app, while humans can easily use it.
Advanced bots can use machine learning to recognize these distorted letters, so these types of CAPTCHA tests are replaced by more complex ones.
Introducing the weaknesses of CAPTCHA and reCHAPTCHA
Using captcha and reccaptcha brings various benefits to websites. But in addition to all the mentioned things, there are still many weaknesses for them.
Captchas do not work properly in many cases and bots solve them and enter the site. Of course, active people in this field are still looking for ways to strengthen captchas. For this reason, they cannot be used with complete confidence and they will not be useful in some cases.
Some people consider the use of captchas to be discriminatory, because people who are visually or hearing impaired often cannot access the required sites.
Introduction of captcha types
There are different types of captchas and any website can use them to test whether it is a human or a robot. The most common types of captcha used are introduced below.
Mathematical problems
CAPTCHA math problems have elementary level math questions like solving 1+3 or solving 1+9. Based on the accuracy of the user’s answer, access to the site will be allowed or denied. This method is one of the most popular captcha mechanisms because bots cannot solve questions related to human logic. This type of captcha is usually implemented in WordPress or HTML sites.
Type letters and numbers
Another type of captcha that is very common and widely used is typing letters. In this method, a number of letters are displayed and you must enter them correctly in the corresponding box. Sometimes letters are combined with numbers or numbers are displayed alone. For people who have vision problems, voice expression is also used.
Show the pictures and find the answer to the question
In another type of captchas, which are considered much more advanced, an image is displayed and the person is asked to identify a specific element in the image. For example, identify traffic lights, mark crosswalks, and such questions that robots cannot answer.
Tick the checkbox
One of the tests that is very simple from the user’s point of view is asking the user to check the specified box. In this test, the movement of the user’s cursor while approaching the checkbox is considered. Even the most direct human movements contain some randomness at the microscopic level. Small unconscious gestures that robots cannot easily imitate.
last word
All websites use various methods, including captchas, to increase security and prevent spam. But what is captcha and what is its use? Captchas are fully automated tests that humans can easily answer, but robots cannot pass. In this article, a complete explanation of captcha, its types and its most important applications was given.
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