Abstract: Electronic voting systems must guarantee security, transparency, and voter privacy simultaneously. This paper presents a secure and transparent e-voting system that integrates blockchain technology, Ethereum smart contracts, differential privacy mechanisms, and email-based One-Time Password (OTP) voter authentication. The proposed system leverages the immutability and decentralization of blockchain to ensure tamper-proof vote recording, while Ethereum smart contracts automate the electoral process without requiring a trusted central authority. Differential privacy is applied to protect individual voter choices from statistical inference attacks, ensuring that aggregate vote counts cannot be traced back to individual voters. Email-based OTP authentication provides a lightweight yet effective two-factor verification mechanism that prevents unauthorized access and double voting. The system architecture includes a voter registration module, a secure login interface, a real-time vote casting and tallying smart contract, and a transparent audit trail accessible to all stakeholders. Security analysis demonstrates resistance to common threats including Sybil attacks, replay attacks, and ballot stuffing. Experimental evaluation shows the system achieves high throughput, low latency, and strong privacy guarantees. This approach addresses key limitations of existing e-voting platforms and contributes a practical framework for conducting elections that are simultaneously verifiable, anonymous, and resilient to adversarial manipulation.

Keywords: Blockchain, Differential Privacy, E-Voting, Ethereum, Smart Contracts, Voter Authentication

Downloads: | DOI: 10.17148/IARJSET.2026.13381