Analysis of hybrid attack and defense based on block withholding strategy

Abstract

As the most influential digital cryptocurrency in the world, Bitcoin is widely recognized for its Proof of Work (PoW) consensus mechanism. However, the blockchain system based on PoW has also encountered many attacks and threats. Most of the current research focuses on analyzing the impact of a single attack on revenue while ignoring the effect of hybrid attacks on the blockchain system and attack revenue. We aim to study the impact of hybrid attacks and defensive measures. In this paper, we extend the block withholding attack model based on the existing selfish mining model and add bribery attacks to the attack model. We compare the benefits under different computing capabilities and theoretically analyze the defense model to prevent attacks. Finally, we compare the advantages of attackers under the attack model and the defense model. Our experiments show that different attack combinations can have negative effects, and the defense model with hidden target values can solve block withholding attacks well.