Voting with Time Commitment for Decentralized Governance: Bond Voting as a Sybil-Resistant Mechanism

In this paper, we examine the usefulness of time commitment as a voting resource for decentralized governance when the identity of voters cannot be verified. In order to do so, we take a closer look at two issues that confront token-based voting systems used by blockchain communities and organizations: voter fraud through the creation of multiple identities (Sybil attack) and concentration of voting power in the hands of the wealthy (plutocracy). Our contribution is threefold: first, we lay analytical foundations for the formal modeling of the necessary and sufficient conditions for a voting system to be resistant to a Sybil attack; second, we show that tokens as the only instrument for weighting votes cannot simultaneously achieve resistance to both Sybil attacks and a plutocracy in the voting process; and third, we design a voting mechanism, bond voting, that is Sybil resistant and offers a second instrument (time commitment) that is effective for countering plutocracy when large token holders also have a relatively high opportunity cost of locking tokens for a vote. Overall, our paper emphasizes the importance of time-based suffrage in decentralized governance. This paper was accepted by Joshua Gans, business strategy. Funding: This work was supported by Gitcoin (Using commitment voting for better DAO governance) and the Australian Research Council [Grant DP200101808].