 | A CAPTCHA, "c ompletely utomated to p ublic T Uring test to tell omputers c and h umans in part", is a test that can determine whether the user is actually |
human and not a computer. These methods are used to prevent bots from using services like writing comments or fill out the form. The use of captcha appears to be essential to prevent the proliferation of spam.
How to judge a good captcha
Many of you will think that a good captcha is the most difficult to solve. So to make life difficult for the algorithms. For those of type visual exist in fact algorithms able to convert an image in a text called Optical Character Recognition.
I believe that the characteristics that make a good captcha are others, such as accessibility, ease of understanding by a human, can be generated automatically and at the same time complex enough to not be able to be solved by algorithms also based on artificial intelligence.
The challenge I set myself is to be able to make a single captcha that has these characteristics. Why do I say unique, because more and more sites use more than one authentication method in parallel as a view supported by an audio captcha. After they realized that one or both of them are not effective.
Accessibility
For years the visual captcha have been responsible for serious discrimination against anyone with sight problems. Their existence has made it inaccessible to millions of sites that have adopted them as a defense against spammers, interposing a barrier which most people already considered insurmountable, between the user and the service network.
Nothing gets from the online petitions against this type of captcha, which continue to proliferate undisturbed on the web. Furthermore, new generations of captchas, designed to withstand the most sophisticated software for text recognition, can be very difficult or impossible for many users, even in full possession of his eyesight.
Precisely for this reason the captcha perfect shall be neither visual nor auditory type.
Automatic generation
The solution is to adopt methods textual. But it is not always possible. Questions like: What color was the white horse of Napoleon? What is the result of two or seven? There be good for accessibility, and human understanding of the problems to be solved by programs.
Their only problem is the impossibility of being able to automatically generate these questions making this method practically unusable.
Easy to fix for users
The methods used are not always be easy to fix for users, you can see in the picture a form for recording very difficult.
hard captcha
A good captcha
Reading this you realize how difficult it is to reconcile the effectiveness and ease of use of a good way to protect their resources. For this reason I decided to develop one myself, that it will not be perfect, but the captcha say that its features are very good.
It is a captcha text, simple to automatically generate, and easy to solve for the users. The hardest job was not the implementation but as so often has been researching the idea right.
The idea is to take a word long enough and swap the position of two different letters. The user must correct the misspelled word.
captcha
The use of this method has been employed in site musicians in the section used to request information .
The only deficiency of this method is that with a simple algorithm is possible to solve it. But I also believe that there is no need to use a safe to protect a few dollars. So waiting to get a better idea and to finally put an end to the search of the perfect captcha consiglirvi and continue to use this method.
