Two research teams—one from Sorbonne University in France and another from the University of Geneva in Switzerland—have tested new methods for electronic voting that use principles from quantum physics. Their findings, published in the journal Physical Review Letters, suggest that quantum-based voting systems could protect voter anonymity while allowing votes to be cast electronically, without the need for a central authority to oversee the process. These protocols build on a 2022 proposal from Sorbonne University researchers, which aimed to create an anonymous and publicly checkable method for electronic voting. The Sorbonne team developed a high-performing source that can generate special quantum states known as GHZ (Greenberger-Horne-Zeilinger) states, which involve multiple particles (in this case, photons) being entangled. These entangled states are crucial for implementing the quantum voting protocol. Meanwhile, the Geneva team used similar techniques to create GHZ states and conducted an experimental test of the voting protocol in a simulated election with four voters and two candidates. This was the first time the protocol had been tested in a real-world-like setting. The quantum voting protocol works by encoding votes in a way that prevents observers from learning individual votes, even if they can see the results of the overall election. In the non-quantum version of the protocol, voters are given secret numbers and vote in rounds. The quantum version uses GHZ states to generate a sequence of random bits, ensuring the total number of 1s is even. Only one person can change their bit during each voting round, and quantum entanglement ensures that this process remains anonymous. Each voter receives one qubit—represented by a photon in the experiment—taken from an n-qubit GHZ state. These states are designed so that when everyone measures their qubit in a specific way, the total number of 1s is even, but the individual results remain random and untraceable. One challenge in using quantum states for voting is that measuring a qubit disrupts its quantum state, making it difficult to both verify the state and use it for voting. To address this, the Geneva team ran the protocol in multiple rounds, randomly deciding whether to verify the state or use it for voting, with a strong preference for verification. The Sorbonne team's approach assumes that the quantum source is independent of any devices that might store quantum states, reducing the need for advanced quantum memory technology. These experiments represent the first practical demonstrations of secure quantum voting protocols, which can be implemented with current technology. Researchers are now working to improve the protocol's security and reliability, aiming to scale up the system for use with more voters and over greater distances.