Explained: How EVMs Record Your Vote, And How VVPAT System Works

Polling for the first phase of Lok Sabha election is being held amid a legal battle in the Supreme Court over Electronic Voting Machines (EVM), first introduced in 2004. The petitioners have sought 100% cross-verification of votes cast on EVMs with paper slips generated through the VVPAT system.

During the arguments, suggestions to revert to the ballot voting system have also come up, with the petitioners pointing to the European nations. The court, however, has told the petitioners not to make such comparisons, observing that the population of West Bengal is more than that of Germany. Yesterday, the Election Commission of India's counsel explained how the EVM system works and why it is foolproof against any form of tampering. The petitioners have raised the issue of the trust of voters in the system and sought tweaks in the current process.

Here is a rundown of what an EVM is and how it is used for voting

EVM: The Machine And Components

An EVM has two units -- the control unit and the balloting unit. These are connected by a cable. The EVM's control unit is with the presiding officer, also known as polling officer. The balloting unit is kept in the voting compartment, where people cast their votes. The balloting unit is usually covered on all sides for the voter's privacy.

At the voting booth, the polling officer verifies your identity and then presses the ballot button that enables you to vote. On the ballot unit are candidates names and symbols with blue buttons next to them. The voter has to press the button next to the name of the candidate of his/her choice.

The Voting Process

The control unit with the polling officer has multiple buttons. One of them is titled 'ballot'. Once the officer presses this button, a red light titled 'busy' comes alive. This indicates that the control unit is ready to record a single vote. A green light on the ballot unit, where the voter is, switches on, signalling that the machine is ready for voting. The voter then presses the button next to the name of the candidate of his/her choice. The ballot unit also has Braille script for visually-impaired voters.

Once the voter casts the vote, the control unit emits a beep sound, indicating that the voting is complete. The control unit also has an LED screen and buttons that can be used to see the total number of votes recorded on it. After all votes are recorded, the polling officer presses a button on the side of the control unit, sealing the machine. On counting day, a button titled 'result' is used to see candidates-wise total votes. There is also a 'clear' button that can be used to erase all data from the control unit.

What Is The VVPAT?

The VVPAT -- Voter Verified Paper Audit Trail -- enables a voter to see if the vote was cast properly and went to the candidate he/she supports. Once a voter presses the button next to the name of the candidate of choice, the VVPAT, which is connected to the control unit and ballot unit, generates a paper slip that is visible to the voter for seven seconds. After that, the paper slip falls into a dropbox in the VVPAT machine.

Currently, votes recorded on 5 VVPAT machines are cross-checked with the EVMs in every Assembly segment. The petitions in Supreme Court want 100% cross-checking of VVPAT slips with votes recorded on EVMs. The petitioners have also sought that the seven-second light on the VVPAT stays on so that the voter can check if his/her vote has been recorded properly. Another suggestion was to issue the paper slip to voters. The Election Commission has contested this, saying it affects voter secrecy and may be misused.

The Case For EVM System

According to the Election Commission, the EVM system is foolproof. The poll body says it saves vote counting time, is tamper-proof and user-friendly. It is also lightweight and robust -- this is critical in a country where polling officials have to trek long distances and even climb hills to reach far-flung polling booths. The EVM is capable of self-diagnosis and is a standalone machine.

The EVMs do not need electricity and come with battery/power packs. This is again a crucial feature that enables voting in areas that do not have a stable power supply. Well before every election, a First Level Checking (FLC) of EVMs and VVPATs is carried out. During this check, the data on the EVMs is erased and the functionality of different components is screened. This check-up is carried out in the presence of representatives of political parties.