Date of Award

Spring 5-15-2022

Degree Type


Degree Name

Doctor of Philosophy (PhD)


Electrical Engineering and Computer Science


Tang, Yuzhe


Blockchains, Denial of Service Attacks, Distributed system security, Ethereum, Peer-to-Peer Networks, RPC service and Mempool

Subject Categories

Computer Engineering | Computer Sciences | Engineering | Physical Sciences and Mathematics


This thesis aims to examine the security of a blockchain's communication network. A blockchain relies on a communication network to deliver transactions. Understanding and hardening the security of the communication network against Denial-of-Service (DoS) attacks are thus critical to the well-being of blockchain participants. Existing research has examined blockchain system security in various system components, including mining incentives, consensus protocols, and applications such as smart contracts. However, the security of a blockchain's communication network remains understudied.

In practice, a blockchain's communication network typically consists of three services: RPC service, P2P network, and mempool. This thesis examines each service's designs and implementations, discovers vulnerabilities that lead to DoS attacks, and uncovers the P2P network topology. Through systematic evaluations and measurements, the thesis confirms that real-world network services in Ethereum are vulnerable to DoS attacks, leading to a potential collapse of the Ethereum ecosystem. Besides, the uncovered P2P network topology in Ethereum mainnet suggests that critical nodes adopt a biased neighbor selection strategy in the mainnet. Finally, to fix the discovered vulnerabilities, practical mitigation solutions are proposed in this thesis to harden the security of Ethereum's communication network.


Open Access