Decentralized Voting System Using Blockchain and Web3

Conventional electronic voting depends on a central server and database, so voters and observers must trust the organization that operates them. This paper presents a decentralized voting application in which the main election rules are enforced by a Solidity smart contract running on an Ethereum-compatible blockchain. A React and Next.js front end communicates with the contract through Web3 and an Ethereum wallet. The organizer, who deploys the contract, registers candidates and voters and activates or deactivates voting. Before a vote is accepted, the contract checks that voting is active, that the sender is a registered voter, that the voter has not voted before, and that the chosen candidate exists. Accepted votes update the candidate's count and emit events that the interface uses to refresh its data. The system is built with open-source tools (Hardhat, OpenZeppelin, Ethers, Next.js) and is presented as a working prototype. The paper describes the architecture, data structures, modules and test cases, shows the user-interface screens, and discusses limitations such as voter authentication, privacy, scalability and the absence of an automated test suite for the voting contract.