International Joint Conference On Theoretical Computer Science – Frontier of Algorithmic Wisdom

August 15-19, 2022, City University of Hong Kong, Hong Kong

 

Invited Speakers

Track B


Insightful Mining Equilibria

Mengqian Zhang

Shanghai Jiao Tong University

Abstract:
The selfish mining attack, arguably the most famous game-theoretic attack in blockchain, indicates that the Bitcoin protocol is not incentive-compatible. Most subsequent works mainly focus on strengthening the selfish mining strategy, thus enabling a single strategic agent more likely to deviate. In sharp contrast, little attention has been paid to the resistant behavior against the selfish mining attack, let alone further equilibrium analysis for miners and mining pools in blockchain as a multi-agent system. In this talk, first, we propose a strategy called insightful mining to counteract selfish mining. By infiltrating an undercover miner into the selfish pool, the insightful pool could acquire the number of its hidden blocks. We prove that, with this extra insight, the utility of the insightful pool could be strictly greater than the selfish pool’s when they have the same mining power. Then we investigate the mining game where all pools can either choose to be honest or take the insightful mining strategy. We characterize the Nash equilibrium of this mining game and derive three corollaries: (a) each mining game has a pure Nash equilibrium; (b) there are at most two insightful pools under equilibrium no matter how the mining power is distributed; (c) honest mining is a Nash equilibrium if the largest mining pool has a fraction of mining power no more than 1/3.
Based on joint work with Yuhao Li, Jichen Li, Chaozhe Kong, and Xiaotie Deng.

Bio:
Mengqian Zhang is a Ph.D. student in the Department of Computer Science and Engineering at Shanghai Jiao Tong University. Before this, she got the B.E. degree in computer science from Ocean University of China in 2018. Since July 2019, she has been a visiting scholar at Center on Frontiers of Computing Studies, Peking University. Her research interests include blockchain and algorithmic game theory.