We have made modifications to the SnapshotX core repo which you can find here: https://github.com/snapshot-labs/sx-evm

Description

This repo demonstrates how you can enable private voting on Inco using FHE.

We have made modifications to the following contracts:

Space.sol :

• We have modified the 'vote', 'execute', and 'getProposalStatus' functions to work with encrypted types of TFHE library.
• choice enum is converted to uint8 choice which is then encrypted as ciphertext in the bytes format.
• votePower is converted from uint256 to euint32 (votePower mapping is where all the votes of (For, Abstain, Against) are aggregated)

ebool isAgainst = TFHE.eq(TFHE.asEuint8(choice), TFHE.asEuint8(0));
ebool isFor = TFHE.eq(TFHE.asEuint8(choice), TFHE.asEuint8(1));
ebool isAbstain = TFHE.eq(TFHE.asEuint8(choice), TFHE.asEuint8(2));

votePower[proposalId][0] = TFHE.add(votePower[proposalId][0], TFHE.cmux(isAgainst, TFHE.asEuint32(votingPower), TFHE.asEuint32(0)));
votePower[proposalId][1] = TFHE.add(votePower[proposalId][1], TFHE.cmux(isFor, TFHE.asEuint32(votingPower), TFHE.asEuint32(0)));
votePower[proposalId][2] = TFHE.add(votePower[proposalId][2], TFHE.cmux(isAbstain, TFHE.asEuint32(votingPower), TFHE.asEuint32(0)));

Execution Strategy Module :

• Modified execute and getProposalStatus and it's helper functions '_quorumReached' and '_supported':

function _quorumReached(uint256 _quorum, euint32 _votesFor, euint32 _votesAbstain) internal view returns (bool) {      
        euint32 forAndAbstainVotesTotal = _votesFor + _votesAbstain;
        return TFHE.decrypt(TFHE.ge(forAndAbstainVotesTotal,TFHE.asEuint8(_quorum)));
    }

function _supported(euint32 _votesFor, euint32 _votesAgainst) internal view returns (bool) {            
        return TFHE.decrypt(TFHE.gt(_votesFor,_votesAgainst));
    }

Testing

To compile the code:

pnpm install
cp .env.example .env 
npx hardhat compile --network inco 

To test the code:

npx hardhat test --network inco