Have you ever filled out a form on a web page and before you submit the form had to decode a series of jumbled up letters and numbers? This is known as CAPTCHA. Standing for Completely Automated Public Turning test to tell Computers and Humans Apart (CAPTCHA) the forms have played a big part in cyber security. Here at Superfast IT with over 15 years of IT support we’ve seen CAPTCHA become an essential part of online security.
CAPTCHA was first seen in the early 2000’s with PayPal being one of the first major sites to introduce the forms. The main reason for the introduction of the forms was due to the rise in computer spam in the early 2000’s as people were learning quickly how to exploit websites. Over the years CAPTCHA has become an essential part of online forms to help tell the difference between humans and machines.
Why CAPTCHA is needed
The main reason for the introduction of CAPTCHA was due to the rise of computer spam at the turn of the century. Adding CAPTCHA to a form would stop any automated submissions going through. Not only has it helped with spam it has also become a benchmark for AI problem-solving.
How it works and characteristics
It may look like a mix of random letters and numbers, but there is an algorithm to CAPTCHA. Due to there being things computers cannot tell apart CAPTCHA follows these rules;
The variation of letters and numbers
Each letter or number can be written in an infinite number of ways. Humans can tell the differences between these infinite ways easily, but artificial intelligence isn’t able to do this. While humans have learned how to distinguish between letters and numbers at high speed to teach a computer to do this is complicated.
Separating joined letters
Most CAPTCHA forms will have letters and numbers that are all joined. Humans can distinguish this and can pull apart the text into different sections easily. With the characters, close together and overlapping it makes it difficult for computers to tell them apart.
This is where humans can excel at solving things such as CAPTCHA. Due to the capability of being able to keep different scenarios alive and pick the correct path to follow, humans take on average just 10 seconds to solve a CAPTCHA form. For example a human can quickly distinguish between ‘i’, ‘I’, ‘l’, ‘L’ and ‘1’ where as artificial intelligence cannot.
It’s hard to imagine that a thing that stops online spam can draw any controversy to itself, yet CAPTCHA has done this since its creation. Instead of designing software that could solve or bypass the forms people started to create ‘CAPTCHA farms’ which would pay minimal amounts for people to solve thousands of CAPTCHA forms.
Its biggest criticism has come from people who suffer from poor vision and/or hearing. CAPTCHA offers an audio version of the mixed-up letters and numbers for people who struggle with their sight. Not only is this a less safe method of cyber security it’s also difficult for people with poor vision to find and access. People who struggle with their sight will often use an on screen reader to help them navigate web pages. On screen readers are unable to read CAPTCHA forms are often leaving people without access to some of the world’s biggest sites.
Despite the world becoming connected more and more by technology CAPTCHA has survived the test of time and is still used today. On criticism of it was it takes too long to solve and was taking up too much time in people’s days. To counteract this a more modern version of CAPTCHA has been introduced. Rather than a mix of letters/numbers, there will be either a series of images or a simple maths equation displayed. The image will then ask you an easy question such as ‘click on the dog’ or ‘click every image that contains the colour blue’. This updated version of CAPTCHA has been met with good reviews but have been criticised by cyber security professionals for being too easy to solve.
What do you think of CAPTCHA?
We hope this guide has helped when it comes to understanding CAPTCHA and why it is used. What are your thoughts on the form protection application, should a more modern alternative be used or is it okay how it is? Let us know down in the comments below.