Novel bribery mining attacks in the bitcoin system and the bribery miner's dilemma

TL;DR

This paper introduces two novel bribery mining attacks in Bitcoin, analyzes their impact on miners' strategies, and proposes mitigation measures, highlighting ongoing challenges in preventing such attacks.

Contribution

It presents new bribery-based mining attacks and analyzes the bribery miner's dilemma, offering insights and mitigation strategies for these advanced threats.

Findings

Bribery semi-selfish mining increases adversary rewards.

Bribery stubborn mining causes target miners to suffer losses.

Proposed mitigation measures can reduce attack effectiveness.

Abstract

Mining attacks allow adversaries to obtain a disproportionate share of the mining reward by deviating from the honest mining strategy in the Bitcoin system. Among them, the most well-known are selfish mining (SM), block withholding (BWH), fork after withholding (FAW) and bribery mining. In this paper, we propose two novel mining attacks: bribery semi-selfish mining (BSSM) and bribery stubborn mining (BSM). Both of them can increase the relative extra reward of the adversary and will make the target bribery miners suffer from the bribery miner dilemma. All targets earn less under the Nash equilibrium. For each target, their local optimal strategy is to accept the bribes. However, they will suffer losses, comparing with denying the bribes. Furthermore, for all targets, their global optimal strategy is to deny the bribes. Quantitative analysis and simulation have been verified our theoretical analysis. We propose practical measures to mitigate more advanced mining attack strategies based on bribery mining, and provide new ideas for addressing bribery mining attacks in the future. However, how to completely and effectively prevent these attacks is still needed on further research.