-Involves the scanning of retina and analysis the layer of blood vessels at the back of the eye.
-Requires the user to remove glasses, place their eye close to the device and focus on a certain point. Whether than accuracy can out weight the public discomfort is yet to be seen.
-Voice recognition system compares a person's live speech with their stored voice pattern.
-Requires user to speak into a microphone. What he speaks can be his password or an access phrase.
Signature Verification System
-Signature verification system recognizes the shape of your handwritten signature, as well as measuring the pressure exerted and the motion used to write the signature.
-Uses special pen and tablet. After pre-processing the signature, several features are extracted.
-The authenticity of a writer is determined by comparing an input signature to a stored reference set (template) consisting of three signatures.
2) Callback System
-Callback System refers to the checking system that authentication the user.
-The Callback System is commonly used in the bank operation and business transaction.
-For example, when you book for the taxi service, the operator will ask you to hang up and she will call you back to confirm for the service required.