To sum it all up, we started off this tutorial by discussing what\u00a0CAPTCHA<\/strong>s really are and the reasons why they are needed i.e. to tell a human user apart from a bot and in a nutshell, to prevent someone from exploiting a site or application\u2019s weaknesses, etc. We talked about how a\u00a0CAPTCHA\u00a0<\/strong>plays with a human\u2019s strengths and a computer\u2019s weaknesses, we then touched upon the different types of\u00a0CAPTCHA<\/strong>s like text, audio, image, etc. We also learned that besides ensuring a site\u2019s security, the information gathered through\u00a0CAPTCHA<\/strong>s can be an effective way of involving human intellect to create a full-fledged dataset for AI or ML. Lastly, we talked about the different advantages or usefulness of\u00a0CAPTCHA<\/strong>s overall.<\/p>\n<\/div>\n<\/div>\n<\/section>\n<\/div>\n<\/div>\n<\/article>\n [\/vc_column_text] Build smarter AI with us.<\/p>See what we can do for you.<\/h3>
\ud83d\udd11<\/strong> In 6 minutes you will learn:<\/strong><\/span><\/p>\n <\/p>\n [\/vc_column_text]<\/div><\/div>[\/vc_column][\/vc_row][vc_row pix_particles_check=””][vc_column] Many of you may or may not be familiar with the term \u2018CAPTCHA<\/strong>\u2019 itself, but would have definitely come across it at some point while surfing the internet. Let me remind you.<\/p>\n <\/p>\n <\/p>\n You MUST have seen an image similar to this while trying to create an account on a website, posting a comment on a blog, or while purchasing something online. Tests similar to the image above are called\u00a0CAPTCHA<\/strong>s, short for\u00a0Completely Automated Public Turing Tests to Tell Computers and Humans Apart<\/em>. So in this tutorial, we will be discussing what\u00a0CAPTCHA<\/strong>s are, the main concepts behind these tests, and how they work in general. We will talk about the different types of\u00a0CAPTCHA<\/strong>s, as well as some of the applications of\u00a0CAPTCHA<\/strong>s, an immensely important one being data collection for Machine learning or Artificial Intelligence projects. So without further ado, let\u2019s get started!<\/p>\n [\/vc_column_text][\/vc_column][\/vc_row][vc_section full_width=”stretch_row” pix_over_visibility=”” css=”.vc_custom_1650444445523{padding-top: 80px !important;padding-bottom: 80px !important;background-color: #f8f9fa !important;}” el_id=”pix_section_program”][vc_row full_width=”stretch_row” pix_particles_check=””][vc_column content_align=”text-center” offset=”vc_col-lg-offset-0 vc_col-lg-12 vc_col-md-offset-1 vc_col-md-10″] Basically,\u00a0CAPTCHA\u00a0<\/strong>is a test that is supposed to differentiate between human beings and computers based on traits or characteristics that are possessed by only humans but not by machines. While performing an activity such as signing up on a website, you are required to type in a sequence of characters, letters, or digits that are given or select a particular set of images, e.g., that of cats, to prove that you are actually a human and not a machine. This is because machines cannot make out a distorted or puzzled text while humans can. For the visually impaired, there is Audio\u00a0CAPTCHA<\/strong>, which includes garbled spoken letters that cannot be identified or understood by machines. All of this is done to prevent bots or automated computer programs from getting unauthorized access to an application.\u00a0CAPTCHA<\/strong>\u00a0stops from adding spans and malicious URLs to an application\u2019s database, hampering an application\u2019s performance, or endangering its security in any other way. In short, the goal is to stop anyone from trying to exploit any weaknesses or shortcomings of a system.<\/p>\n <\/p>\n There are several different types of CAPTCHAs. We will introduce the six most popular ones here.<\/p>\n [\/vc_column_text][vc_column_text css=”.vc_custom_1655943943946{border-top-width: 1px !important;padding-top: 60px !important;padding-bottom: 30px !important;border-top-color: rgba(0,0,0,0.2) !important;border-top-style: solid !important;}”]<\/p>\n <\/p>\n This is the most common type of\u00a0CAPTCHA\u00a0<\/strong>where you are given a sequence of characters with a slight variation or distortion, and you are supposed to type them in the given input field.<\/p>\n <\/p>\n <\/p>\n Image recognition\u00a0CAPTCHA\u00a0<\/strong>consists of different forms of image tests which can include naming images, distinguishing images from a set of different images, as well as identifying an odd image out of the set. This type of\u00a0CAPTCHA\u00a0<\/strong>makes use of the bots\u2019 weaknesses in solving image recognition related problems which is a human\u2019s forte.<\/p>\n <\/p>\n <\/p>\n As mentioned before, this type of\u00a0CAPTCHA\u00a0<\/strong>is for the visually impaired. It mostly consists of audio of spoken letters or numbers which are slightly distorted in order to puzzle a bot but easy for a human to comprehend.<\/p>\n <\/p>\n <\/p>\n While trying to register or create an account on a website, you are sometimes asked to sign up using your social media accounts e.g., Facebook account, Gmail account, etc. This is done because bots do not have social media accounts, so this method prevents them from registering. It also saves the authentic user\u2019s time as he\/she does not need to create an account from scratch and can instead use an already created social media account. As the accounts are genuine, this method of registering helps to increase a site\u2019s security.<\/p>\n <\/p>\n A form appears with a simple math problem, requiring you to solve for the answer. Most of the questions involve simple arithmetics e.g. 8+2, 11\u20139, etc. These can be quite tricky for robots to solve because it has to perform not only image recognition but also a multiple semantic analysis of numbers and symbols to solve the problem.<\/p>\n <\/p>\n Recording the amount of time taken to solve a form and differentiating between a bot and a human on the basis of that time is another type of\u00a0CAPTCHA<\/strong>. Bots mostly fill out all the fields in a form immediately whereas humans naturally take some time to enter the information.<\/p>\n [\/vc_column_text][\/vc_column][\/vc_row][vc_section full_width=”stretch_row” pix_over_visibility=”” css=”.vc_custom_1650444445523{padding-top: 80px !important;padding-bottom: 80px !important;background-color: #f8f9fa !important;}”][vc_row full_width=”stretch_row” pix_particles_check=””][vc_column content_align=”text-center” offset=”vc_col-lg-offset-0 vc_col-lg-12 vc_col-md-offset-1 vc_col-md-10″]\n
![\"\"](\"https:\/\/blog.datumo.com\/en\/wp-content\/uploads\/2022\/06\/01.png\")
What is a CAPTCHA, and Why is it needed?<\/h2><\/div>[vc_column_text css=”.vc_custom_1655945390911{padding-top: 40px !important;}”]<\/p>\n
![\"\"](\"https:\/\/blog.datumo.com\/en\/wp-content\/uploads\/2022\/06\/Frame-2746-1024x731.png\")
[\/vc_column_text][\/vc_column][\/vc_row][\/vc_section][vc_row pix_particles_check=””][vc_column]Different types of CAPTCHAs<\/h2><\/div><\/div><\/div>[vc_column_text css=”.vc_custom_1655943791425{padding-top: 60px !important;padding-bottom: 30px !important;}”]<\/p>\n
1. Character or Text Recognition<\/strong><\/h5>\n
![\"\"](\"https:\/\/blog.datumo.com\/en\/wp-content\/uploads\/2022\/06\/0_Qb_HRisf8FeOmCdZ.jpeg\")
2. Image Recognition<\/strong><\/h5>\n
![\"\"](\"https:\/\/blog.datumo.com\/en\/wp-content\/uploads\/2022\/06\/capcha.png\")
3. Audio CAPTCHA<\/strong><\/h5>\n
![\"\"](\"https:\/\/blog.datumo.com\/en\/wp-content\/uploads\/2022\/06\/0_Jn9WKLKUHUEuiKnh.png\")
4. Social media login<\/strong><\/h5>\n
![\"\"](\"https:\/\/blog.datumo.com\/en\/wp-content\/uploads\/2022\/06\/0_EgXQo3CVZf5LyjAD.jpeg\")
5. Math problem<\/strong><\/h5>\n
![\"\"](\"https:\/\/blog.datumo.com\/en\/wp-content\/uploads\/2022\/06\/dd-1.png\")
[\/vc_column_text][vc_column_text css=”.vc_custom_1655944839837{border-top-width: 1px !important;padding-top: 60px !important;padding-bottom: 30px !important;border-top-color: rgba(0,0,0,0.2) !important;border-top-style: solid !important;}”]<\/p>\n6. Time-based CAPTCHA<\/strong><\/h5>\n