Routing Attacks on Cryptocurrency Mining Pools

Mining pools have been the driving force for ensuring the security of multiple proof-of-work (PoW) cryptocurrencies. Under the de facto protocol Stratum, pools allow miners to collaborate, discover new blocks, and earn rewards collectively. Recently, the blockchain community has been promoting the adoption of a more secure Stratum protocol known as Stratum V2. In this paper, we introduce Erosion, a novel network-level attack that applies to both Stratum and Stratum V2 protocols. The essence of the Erosion attack lies in its ability to disrupt connections between miners and a targeted mining pool, significantly impairing the miners’ contributed PoWs and reducing the victim’s mining power. We also discover a vulnerability in the Stratum V2 protocol that allows the adversary to persistently disrupt a connection by tampering with a single packet, thus enhancing the attack’s stealthiness. Our survey shows that the Erosion adversary can readily execute attacks against a significant majority (e.g., 91%) of mining pools across the top ten cryptocurrencies. We also observe an extreme mining centralization that enables Erosion adversaries to simultaneously target multiple pools and cryptocurrencies. Furthermore, our focused evaluation of pooled mining in Bitcoin reveals that thousands of different adversaries can gain control over the majority of Bitcoin mining power, with one potentially malicious Autonomous System capable of taking down 96% of the total mining power.