Weighted Voting on the Blockchain: Improving Consensus in Proof of Stake Protocols
This addresses security and reliability issues in blockchain consensus for decentralized networks, but it is incremental as it builds on existing PoS frameworks.
The paper tackles the vulnerability of Proof of Stake protocols to faults from validators who abstain, by proposing a weighted voting mechanism that scales votes based on behavior and rewards, resulting in a more robust consensus mechanism as shown numerically and analytically.
Proof of Stake (PoS) protocols rely on voting mechanisms to reach consensus on the current state. If an enhanced majority of staking nodes, also called validators, agree on a proposed block, then this block is appended to the blockchain. Yet, these protocols remain vulnerable to faults caused by validators who abstain either accidentally or maliciously. To protect against such faults while retaining the PoS selection and reward allocation schemes, we study weighted voting in validator committees. We formalize the block creation process and introduce validators' voting profiles which we update by a multiplicative weights algorithm relative to validators' voting behavior and aggregate blockchain rewards. Using this framework, we leverage weighted majority voting rules that optimize collective decision making to show, both numerically and analytically, that the consensus mechanism is more robust if validators' votes are appropriately scaled. We raise potential issues and limitations of weighted voting in trustless, decentralized networks and relate our results to the design of current PoS protocols.