What is CAPTCHA? A CAPTCHA is an automated form of challenge-response testing used in computer programming to identify whether or not the user agent is human. More formally known as a “CRF-“: Challenge Response Function, a CAPTCHA requires that the user respond to an offer with a challenge number before being given the password.
In practice, there are two types of CAPTCHAS: a human-based and a completely automated public Turing test to tell and computers apart. The first type of CAPTCHA involves answering a set of increasingly difficult questions intended to trick the computer into thinking the answer was a secret, which is not (and should not be) the case. This is not the same thing as “computer-imitating” the behavior of a real person. (Note: we do not use the term “commodity detection” in this article; please consult a software developer for that topic.) In the case of a real person, he would most likely be caught if he tried to answer the same questions; and in the case of a computer, he would simply be unable to figure out the answer.
However, because no real person would ever answer such questions, the computer programs have been given a solution in the form of a captcha image. The problem with this solution is that computers cannot see these images; so even though a computer might solve the CAPTCHA easily enough by guessing, it is useless to any user trying to crack the code. Bots, on the other hand, can see these images and easily figure out the correct answer. So even if a bot is solving a CAPTCHA correctly, the users still don’t have the advantage of using a real person. In fact, if a user cannot solve a CAPTCHA he is given a list of all solved CAPTCHAS, and the level of difficulty of each one of them, which makes human users run the other way in order to answer easy ones!
In contrast, image-based CAPTCHAS make it possible for both humans and bots to solve them without losing any time at all. This makes image-based CAPTCHAS an ideal solution for users who are slow at reading letters or have problems reading text. The problem is, however, that these images lack the aesthetic appeal of a text-based CAPTCHA and are much more difficult to look at. This is why many CAPTCHAS still use text-based methods as opposed to image-based ones, but the problem is that many text-based CAPTCHAS are still way too difficult to be of any real benefit. Bottom line, if you are planning to use a CAPTCHA in your website or blog, it is best to use image-based ones instead.
On the other hand, an image-based CAPTCHA can be seen as a solution for CAPTCHAS designed for humans, since they are able to convey the right meaning with the right amount of simplicity. Also, image-based CAPTCHAS are able to adapt themselves to whatever format the user might be using, such as gifs and pngs. All in all, it can be said that image-based CAPTCHAS are very easy to understand and are much more aesthetically friendly than text-based ones. On the other hand, this does not mean that text-based ones cannot be effective – many text-based CAPTCHAS have been able to deliver accurate CAPTCHAS messages to users.
What is CAPTCHA? Without going into the technological aspects of CAPTCHAS, the crux of the matter is that, before a CAPTCHA can be used on a website, it needs to be prepared in advance. This means that the developer who is designing the website needs to make sure that a ready-made code for a CAPTCHA has been written. On the other hand, while text-based CAPTCHAS do not need to be written by hand, they still need to be prepared in advance and validated by humans before they are made available to the users. Since humans can comprehend blocks of characters better than ever, this ensures that the CAPTCHAS sent to the users are as close to perfect as possible.
What is CAPTCHA even supposed to achieve? In practice, a CAPTCHAS message is meant to ensure that a human being will not click on an image that is displayed on a web page because the user may be tricked into thinking that he or she is reading a text-based online dialog. For instance, this would not happen if the images were loaded as JPEG’s instead of as ‘text files’. For online marketers working with JPEG’s, this is an excellent way to ensure that their clients will not accidentally click on an image when they meant to read a text prompt. In effect, this also ensures that online users are given the extra layer of security that text-based online dialogues could provide without sacrificing the overall visual appeal of the site.
So, we’ve been introduced to the mystery of ‘what is captcha’. It is important that we, as online users, do all we can to avoid being tricked into clicking on image files that do not actually mean anything! Even if the file looks like a common image format, such as JPEG or GIF, it may still be malicious in nature. As long as we remember that a ‘captcha’ is simply a code used to make certain requests in a manner that increases the chances of successful access, we will have minimal trouble safeguarding ourselves from unwanted surprises. In the end, we must be willing to invest a small amount of time every time we visit a site to ensure that we do not get tricked into reading or clicking a link that is malicious in nature.