The term EVMs refers to Electronic Voting Machines, which are a type of mechanism used as the standard means of conducting elections in India. The idea for EVMs was first proposed in 1977, and a working model was developed in 1979 by the state-owned Electronics Corporation of India (ECIL) and Bharat Electronics (BEL). The machines were created to solve problems associated with the paper ballot system, such as high cost, time-consuming manual counting, and fraudulent practices like booth capturing and ballot stuffing.
The first limited trial of EVMs took place in May 1982 in the by-election to the Paravur assembly constituency in Kerala. However, their use was initially struck down by the Supreme Court due to the absence of a legal framework. The legal basis for their use was established when the Representation of the People Act, 1951 was amended in December 1988 to include Section 61A, which allows the Election Commission of India (ECI) to use EVMs. EVMs were used nationwide for the first time in all 543 Parliamentary Constituencies during the 2004 General Election.
An EVM is a stand-alone, battery-powered device consisting of two main components: the Ballot Unit (BU) and the Control Unit (CU). The BU, placed in the voting compartment, has buttons for candidates, while the CU, with the presiding officer, records the votes. The CU's program is burned into a microchip on a "one time programmable basis," making it unalterable. The system is designed to prevent fraud by limiting the voting rate to a maximum of five votes per minute.
A significant recent change is the mandatory use of the Voter Verifiable Paper Audit Trail (VVPAT) system, which was introduced following a 2013 Supreme Court directive. The VVPAT is connected to the EVM and prints a paper slip showing the voter's choice, which is visible for seven seconds before dropping into a sealed box. This provides a paper trail for audit. In the N Chandrababu Naidu v Union of India (2019) judgment, the Supreme Court directed the ECI to increase the mandatory VVPAT verification from one to five randomly selected polling booths in each Assembly Segment. The core mechanism of the EVM—the electronic recording of the vote—has stayed the same, but the VVPAT adds a verifiable paper record.