Biometric E-voting was one of the final year project that was presented for engineering degree.
The concept is simple. One vote for one citizen.
Thus in this digital era it is only fair that the identity of the voter is biometrically verified before he impacts the future of the country. In this project we have designed a device that will first ask the user to scan his/her fingerprint in order to proceed with the voting. If the fingerprint is found in the records then the option to select the contesting party will be activated. Once the vote is registered by pressing the appropriate button which is next to the party name, it is saved and next person can cast the vote.
If the same person tries to vote multiple times, the device does not allow the same as the fingerprint would have been marked voted during the first vote. Since this is unique multiple votes can be prevented.
In practical implementations, fingerprints of all the citizens can be fetched from the  Aadhar details and a database can be formed against which the voter fingerprints can be verified.
This also means that the voter is not restricted to that specific booth and can vote from any voting station near him. This could also help in increasing voters percentage.
The project employs a simple algorithm and is just a proof of concept.
It has 20 stored fingerprints in its database and one master/admin fingerprint that will be used to display the total votes of all contesting parties in the end. The device has 4 buttons each representing a different contestant. The LCD screen will display vital messages such as scan finger, cast vote and so on. The Red and Green LEDs also aid in indication of the processes going on.