Quantum Voting Protocol for Centralized and Distributed Voting Based on Phase-Flip Counting

We introduce a quantum voting protocol that uses superposition and entanglement to enable secure, anonymous voting in both centralized and distributed settings.

Votes are encoded via phase-flip operations on entangled candidate states, controlled by voter identity registers.

Tallying is performed directly by measuring the candidate register, eliminating the need for iterative classical counting.

The protocol is described for a centralized single-machine model and extended to a distributed quantum channel model with entanglement-based verification for enhanced security.

Its efficiency relies on basic quantum gates (Hadamard and controlled-Z) and the ability to extract vote counts from quantum measurements.

Practical validation is provided through analytical examples (4 voters with 2 candidates and 8 voters with 3 candidates) as well as numerical experiments that simulate ideal conditions, depolarizing noise, dishonest voter attacks, and sampling convergence.

The results confirm exact probability preservation, robustness against errors, and statistical behavior consistent with theoretical bounds.

The protocol ensures voter anonymity via superposition, formalized as the indistinguishability of tallying transcripts under vote permutations and reinforced by an identity-dephasing step that renders the identity register exactly maximally mixed, prevents double-voting through entanglement mechanisms, and offers favorable complexity for large-scale elections.