Understanding and Hardening Blockchain Systems Security under DoS Attacks

Ethereum is the largest smart-contract platform and second-largest cryptocurrency only after Bitcoin. Under the hood, Ethereum is a peer-to-peer network where miner nodes come to a consensus and decide what transactions to include in the blockchain. In practice, Ethereum’s P2P network receives transactions sent from millions of web clients and propagates them to the tens of thousands of miner nodes. While the blockchain-to-client communication channel is a part of the system’s critical path, its security is understudied in the existing research literature. This talk presents our recent research examining Ethereum systems security under the denial-of-service attack vectors (CCS'21, NDSS'21, and IMC'21). The security vulnerabilities discovered in these works have been confirmed and then fixed by the Ethereum developer community.