Paper 2026/1773

Enforcing Winner-Only Disclosure: Verifiable Tally Hiding for Weighted DAO Governance

Abstract

In weighted voting, an exact tally can reveal individual choices even when every ballot is encrypted. Publishing only the winner does not solve this problem if a tallying party first decrypts the total. We construct a publicly verifiable protocol that enforces winner-only disclosure within the computation. Voters prove that their encrypted contributions equal zero or their registered weight. Five trustees add and compare these contributions while encrypted, then release a decision bit that anyone can verify against the exact ballots accepted on chain. Under our assumptions, accepted-result correctness holds even with all five trustees malicious, with an explicit failure bound and abort allowed. For honestly cast boards, tally-layer privacy holds against up to two statically and actively corrupted trustees, a malicious network, and a malicious publisher: the computation adds no tally-derived plaintext beyond the decision and abort pattern. Retained executions reach 1,024 voters, including independent replay of a 17,406-gate,2.1 GB transcript. A separate historical eight-voter run completes the Arbitrum Sepolia path. The prototype uses test-only setup and demonstrates execution and public verification, not production security.

Note: Revised version with substantially improved exposition, clarified security scope and proofs, expanded evaluation through 1,024 voters, Arbitrum Sepolia evidence, and a new comparison with prior tally-hiding systems.