MACI is focused on building the most secure e-voting solution available. It enables on-chain voting processes with significantly reduced risk of cheating, like bribery or collusion, through the use of Ethereum smart contracts, encryption, and zero-knowledge proofs. Together these technologies provide a set of guarantees including censorship resistance, correct execution, privacy, and a receipt-free voting scheme, which ensures results are transparent but makes it impossible for outsiders to verify how any specific user voted. We believe MACI is most beneficial for governance and funding events, when the stakes are high and anti-collusion mechanisms are critical to help ensure fair and transparent outcomes.