Know About Human Interactive Proofs

Whenever we sign up for a new account in Yahoo,Hotmail,Google and so on,at the end of the registration process we'll be asked to enter the characters present in a randomly generated image as shown in the picture.Why so???What exactly they want from us?

The answer to the above questions is.....
They want to prevent their sites from automated registrations.

Let's see what exactly are these automated registrations.Web services are increasingly becoming part of people’s everyday life. For example, we use free email accounts , we use online polls to gather people’s opinion. But all these Web services designed for human use are being abused by automated computer programs.

These automated computer programs register thousands of free email accounts every minute.These real-world issues have recently generated a brandnew research area called "Human Interactive Proofs (HIP)" which are mainly character based.

These HIPs mainly explore the gap between human and malicious attacks in terms of reading poorly printed or manipulated characters.Figure Above shows a character HIP used in MSN Passport,which consists of distorted characters and random arcs. A user needs to recognize the characters and correctly types in the space below the HIP to prove he/she is a human.

Now,what if a person doesn't know english??To overcome this a new technique called "Face HIP" is designed where a user will be asked to click on 4 points(Ex 2 eyes and 2 mouth corners)on a randomly generated distorted face embedded image.If the user can correctly identify these points, the face HIP concludes the user is a human;otherwise, the user is a machine..