Maharashtra Assembly Elections 2024 | How do EVMs work and are they 'tamper-proof'?

Maharashtra goes to polls in a single phase on November 20, the results of which will be announced on November 23. The massive electoral exercise will see voters stream into 1,86,000 polling stations across the state, as per the Election Commission. Approximately 9.6 crore voters are eligible to vote in Maharashtra.

Electronic Voting Machines (EVMs), despite becoming a staple in recent elections in India, is under scrutiny just before that Maharashtra Vidhan Sabha elections after Haryana voters defied exit polls to vote BJP into power for the third time in a row in the state.

The Election Commission has rejected claims of alleged tampering of EVMs in the Haryana polls. But fears persist about the irregularities in how the EVMs function in real-time.

While announcing the Maharashtra poll dates, Chief Election Commissioner Rajiv Kumar had said the poll body will give detailed responses to complaints of irregularities in Electronic Voting Machines.

How do EVMs work?

The EVM was designed by a team at IIT Bombay.

The machine consists of two units — a control unit, and the ballot unit —connected by a five-meter cable. The ballot unit facilitates the actual voting by a voter and consists of a ballot paper screen with the names of candidates and their symbols alongside labeled buttons, indicator lights and also signage in Braille.

The control unit is responsible for the operational control of the ballot units. It stores the vote counts and displays the results on LED displays. The control unit is pre-programmed at the time of manufacturing and cannot be altered later.

The control unit remains with the Presiding Officer or a Polling Officer and the balloting unit is placed inside the voting compartment. The control unit can store the result in its memory for 10 years and more.

The EVMs do not have any communication components or internet interface that can be 'hacked'.

The Polling Officer in charge of the control unit presses the ‘ballot’ button provided on the unit for releasing the ballot for the voter. It enables the voter to cast his vote by pressing the candidate button (blue button) on the balloting unit against the candidate and party symbol of their choice.

How are the EVMs powered?

The machines are powered by a 7.5 volt battery inserted into the control unit. The design team opted for batteries to charge the machine to prevent the possibility of electricity cuts or power outages in remote areas interfere with the EVMs functioning.

Every EVM can function without a secondary power source.

The two units work only in tandem and cannot work independently. The ballot unit has an internal clock and a pre-programmed protocol by which it records every input-output event with a timestamp provided it is powered.

How many votes can one EVM record?

A single ballot unit can list a maximum of 16 candidates and as a part of an initial design, up to four ballot units could be connected in parallel to a single control unit to cater to a maximum of 64 candidates. After an upgrade in 2013, 24 ballot units can now be connected to a single unit so that it can cater to a maximum of 384 candidates.

A single machine can record a maximum of 2000 votes.

The devices were designed to prevent fraud by limiting the number of new votes can be entered into the machine in a given time frame. In a minute, the EVMs can register a maximum of five votes.

Are EVMs tamper-proof?

"Have you understood this conspiracy? Where there was 99 per cent battery in EVMs, the BJP won. Where there was less than 70 per cent battery, the Congress won. If this is not a conspiracy, then what is it?" Congress party general secretary Jairam Ramesh had said after the Haryana polls results as the party demanded answers from the Election Commission about EVM 'tampering'.

The poll body has however rejected the claim that machines with varying battery strengths give out different results. Referring to the issue over battery strength affecting results, the Chief Election Commissioner Rajiv Kumar said while earlier allegations of hacking had died down, "but this has come up for the first time."

He added that that electronic voting machines (EVM) batteries are "single-use" in nature like the ones used in calculators. "They cannot be recharged like cellphone batteries ... They have a life," he said. Kumar asserted that around six days prior to the poll day, EVMs are commissioned and election symbols of candidates are loaded and a new battery is installed which has signatures of candidates or their authorised agents.

"Leave alone EVM, even batteries (installed) have signatures of candidates. Even we were not aware (of this rule) as it was framed long back. Now it is helping us," he said responding to a series of questions on the reliability of the machines and concerns flagged on battery.

Kumar explained that batteries are used in the control unit of EVMs. New batteries are inserted in the control unit on the day of commissioning in the presence of candidates and are sealed. He explained that initially, the battery provides a voltage between 7.5 and 8 volts. Hence, the battery capacity is displayed as 99 per cent when the voltage is above 7.4.

With the use of the EVM, its battery capacity and consequently the voltage decreases. As the voltage goes below 7.4, the battery capacity is displayed as 98 per cent to 10 per cent, EC officials had earlier explained.

The control unit remains functional when the battery has more than 5.8 volts. It is when it is left with more than 10 per cent capacity and the battery replacement warning appears on the control unit display.

This is similar to the signal displayed in a vehicle when it is running on reserve fuel. The remaining capacity of the battery on the counting day depends upon the mock poll conducted on the control unit, the actual poll and the initial voltage of the battery (8 to 7.5 volts).

An alkaline battery also has the property of regaining its voltage to some extent when kept switched off.