Advancing E-Voting Security: Biometrics-Enhanced Blockchain for Privacy and VerifiAbility (Bebpv)

Achieving individual verifiability and receipt-freeness in e-voting systems poses a complex challenge. Mechanisms that allow voters to confirm their votes may also inadvertently enable them to show proof of their choices to others, thus jeopardizing vote privacy. This creates a critical tension between two essential objectives: enabling individual verifiability, where voters trust the system to accurately count their votes, and maintaining receipt-freeness, where the system prevents exploitation and coercion. The Biometrics-Enhanced Blockchain for Privacy and Verifiability (BEBPV) system proposed in this study addresses this challenge by employing facial biometric authentication and trusted node centres for post-voting verification; the biometric facial authentication reduces risks associated with the resale of voting credentials and removes the need for voters to recall complex passwords, while the post-voting verification process available at secure, trusted node centers allows voters to confirm their votes without retaining any proof that could be shared with third parties, thus upholding receipt-freeness. These mechanisms collectively ensure that individual votes are verifiable, while simultaneously safeguarding against coercion and vote-buying through receipt freeness. The feasibility of the BEBPV system is demonstrated through smart contract implementation for both the voting phase and post voting phase. Additionally, the system is validated on several essential attributes of an e-voting, including fairness, universal verifiability, eligibility and privacy. A technical evaluation indicates a transaction cost of 166,662 gas per vote cast.