How can choosing pictures of certain objects (stop signs, cross walks, cars, etc.) prove that you are not a robot on websites?


It seems weird that to prove that I’m human I have to look for certain objects or check a box. Why is that?

In: Technology

It’s a task that is designed to be difficult for computer programs to solve, but relatively easy for humans to solve.

The goal of Captcha-like challenges is to prevent the use of automated tools from accessing certain web services.

It less proves it so much as makes it highly likely.

Humans have many millions of years of evolution behind highly advanced object recognition. Our brains being able to tell the difference between a tiger and a vaguely tiger-shaped rock is the difference between life and death.

Computers can distinguish between objects too, but in order to do it with a high degree of accuracy (especially when you’re not trying to compare apples to battleships) it requires a fairly high degree of training and computing power.

Can computers choose the 3 images out of 9 that have a fire hydrant in them? Absolutely. Is it a deterrent to people trying to brute force websites when you’re effectively multiplying the amount of time and/or computing power required by 100x or more? Yes.

Because how bots select images on those questions can be detected as automated by the website. People tend to wander with their mouse, and can pretty easily tell the difference between a traffic light and a street light at first glance. Bots tend to be predictably mechanical in the choices they make.

The choosing pictures isn’t really to check if you’re a robot, it instead helps with gathering masses of data for self driving vehicles. Whether you are a human was already decided in the background, depending on a lot of different factors that google doesn’t wanna give out because otherwise botters could use that.

Remember when it was words? Similar thing, one word was the check, the other for Google’s digitalizing of books.

Word and a house number? For google maps.

Edit: some additional bits

Captcha, the system that is used for checking whether you’re human or not, stands for “Completely Automated Public Turing test to tell Computers & Humans Apart”.

And there are several ways to get around these, there are programs out there who are able to solve these tests successfully and seem human, but there have also been instances where humans have been paid to solve Captchas all day long.