Uncle Incentive Mechanism Adjustment against Selfish Mining in Ethereum

Abstract

Selfish mining has potential hazards to blockchain systems by hiding mined blocks and broadcasting them strategically. It lets the adversary gain additional rewards in the mining process which was first proposed in Bitcoin recommended by Satoshi Nakamoto. The blockchain-based application Ethereum using GHOST (Greedy Heaviest-Observed Sub-Tree) protocol with regard to Bitcoin to alleviate the loss of honest miners of stale blocks and compensate uncle blocks which will increase if selfish mining occurs. But it only makes things worse since uncle incentive mechanism reduces the cost of the failure of selfish mining and decreases the threshold of selfish mining pool needed to be profitable. There is no research which focuses on the rationale behind uncle incentive mechanism in Ethereum. This paper focuses on the feasible modifications on uncle incentive mechanism against selfish mining in Ethereum. The uncle block reference behaviors of miners are analyzed when selfish mining occurs in Ethereum by building models. Furthermore, a feasible uncle incentive mechanism against selfish mining is proposed. It is not necessary to have a strategy with a monotonous order with regard to generations of uncle blocks. The uncle incentive mechanism suggested in this paper can efficiently raise the threshold for selfish mining to be profitable by around 3.17%, an increase by around 9.76%. It offers an alternative uncle incentive mechanism for cryptocurrencies which are based on GHOST protocol.