3. The Challenge – Voting Schemes on the Blockchain
At the protocol layer, blockchain networks and DAOs have also much in common.
What a consensus protocol is for blockchain nodes, a voting protocol is for DAO participants.
In fact, one can call a voting scheme a consensus with the additional property of voter privacy. The additional privacy property is necessary to safeguard that the choices made by each voter are taken independently and anonymously. The latter is a prerequisite of the first property and protects voters against rebounds after the ballot.
There are a handful of voting protocols for permissionless blockchains. Yet some research is required to verify their suitability for DAOs.
3.1. The One-Person-One-Vote (1p1v) protocol
Known as the mother of voting mechanisms, the one-person-one-vote scheme is the preferred method to reach a consensus in matters of governance (eg. presidential elections). The scheme permits each eligible voter to cast a vote. Typically a trusted third party (eg. delegates of the government) manage and orchestrate the election. They safeguard the voting follows a protocol of conduct. Once the voting period ended, they count the votes and announce the result following a majority quorum.
One might be tempted to adapt 1p1v to the blockchain setting. However there are problems with that. In a permissionless network wallet addresses serve as the only means to identify a voter. As long as no identity layer is in place to link the addresses with real-world identities, 1p1v falls prey to Sybil attacks. In a Sybil attack a malicious voter simply creates multiple wallet addresses, each permitting him to cast a vote in a ballot. Due to the permissionless nature of the blockchain network, such attacks are unavoidable and hence make 1p1v schemes unsuitable for voting schemes.
1p1v is an unsuitable voting mechanism in permissionless blockchains (as long as no identity layer is in place).