Selfholding: A combined attack model using selfish mining with block withholding attack

Abstract

Bitcoin is one of the most influential digital cryptocurrencies in the world, of which the security is under serious threat. One of the most serious security problems is facing several attacking strategies on the bitcoin protocol, represented by selfish mining and block withholding attacks. In this paper, we propose SelfHolding as a combined attack model based on the selfish mining and block withholding strategies. We mainly focus on the SelfHolding attacker when (i) attacking one honest mining pool; (ii) attacking two honest mining pools. Based on the proposed model, we compute the expected revenue of the attacker and analyze the factors affecting it. Finally, we compare the revenues of an attacker under some other attacking strategies to those of our proposed strategy. Our experiments show that when the attacker’s computing power is relatively small, SelfHolding attack strategy can obtain higher revenues than the classic selfish mining attack.