How we keep your vote private and the result honest.

The Shutter Governance system secures votes using ElGamal homomorphic encryption. This is a special type of encryption that allows votes to be added together while still encrypted. The election authority never needs to decrypt individual votes to count them. They simply add all the encrypted votes together and decrypt only the final sum.

The logical follow up question: couldn't encrypted votes contain anything, like invalid choices or multiple votes by a single voter? That's where zero-knowledge proofs come in. When you submit your encrypted vote, you also submit a mathematical proof that demonstrates your vote is valid without ever revealing your vote. The proofs are tied to the unique voter identity, ensuring that each eligible voter can only submit one valid proof per election. If someone tries to vote twice, the system will detect that a proof from that voter already exists and reject the duplicate. The system rejects any vote without a valid proof and any duplicate submissions, making both ballot stuffing and double voting impossible.

The decryption process uses threshold cryptography, where the decryption key is split among multiple independent parties like election monitors, civic organizations and international observers. A predetermined number of these parties (for example, three out of five) must cooperate to decrypt the final tally, since no single entity can decrypt votes alone. This distributed approach eliminates the need for a central authority that made previous digital voting systems vulnerable.