MACI

MACI, short for Minimal Anti-Censorship Infrastructure, is a protocol and software project aimed at enabling private, verifiable, and censorship-resistant on-chain voting and governance for blockchain networks. Its core goal is to let participants influence decentralized decisions while protecting voter privacy and reducing opportunities for manipulation by intermediaries.

Overview

MACI proposes a system where ballots are collected off-chain and kept confidential, while a final tally is produced and verifiable on the blockchain. Voters submit encrypted ballots to a MACI interface; an aggregator sequences ballots and generates proofs that the tally is correct without revealing individual votes. A smart contract on-chain verifies the proofs and enforces the outcome, allowing governance to proceed without exposing how each participant voted.

Key features

Privacy: individual votes are not revealed on-chain; verification relies on cryptographic proofs to ensure correctness without disclosures.

Censorship resistance: the architecture prioritizes preventing suppression or alteration of votes by intermediary actors.

Verifiability: the tally and process integrity can be publicly audited through cryptographic proofs.

Off-chain processing: much of the ballot handling and proof-generation occurs off-chain to improve scalability.

Architecture and components

MACI typically includes a client library for voters to prepare and submit ballots, an aggregator or bridge that collects ballots and produces proofs, and an on-chain smart contract that stores commitments, enforces rules, and verifies proofs.

Use cases and status

MACI is designed for decentralized organizations and communities seeking private, auditable governance processes. Development has featured prototypes and ongoing discussions within the blockchain governance space, with implementations varying across networks and versions. See also: zero-knowledge proofs, on-chain governance, privacy-preserving voting.