Weighted voting on the blockchain: Improving consensus in proof of stake protocols. Issue 5 (18th February 2020)

• Record Type: Journal Article
• Authors: Leonardos, Stefanos; Reijsbergen, Daniël; Piliouras, Georgios
• Other Names: Ju Hongtaek guestEditor.; Boutaba Raouf guestEditor.; Kim Myungsup guestEditor.; Stiller Burkhard guestEditor.
• Is Part Of: International journal of network management. Volume 30:Issue 5(2020)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2020-02-18
• Subjects: Computer networks -- Management -- Periodicals; 004.6
• DOI: 10.1002/nem.2093
• Languages: English
• ISSNs: 1055-7148

Abstract

Summary: 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. Abstract : To protect against faults caused by accidental or malicious abstention of validators in proof of stake protocols, we design an optimal weighted voting scheme based on validators' voting profiles. The profiles are updated 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 that the consensus mechanism is more robust if validators' votes are appropriately scaled.