  Strategies related to the blockchain concept of Extractable Value (MEV/BEV),
such as arbitrage, front- or back-running create an economic incentive for
network nodes to reduce latency, including minimizing transaction validation
time -- a core feature to secure blockchain networks. A modified node, that
neglects to filter invalid transactions in the Ethereum P2P network, introduces
novel attack vectors. In this work, we formalize and evaluate a Blockchain
Economic Denial of Sustainability (EDoS) attack, which can cause financial
losses in traffic costs for operators of modified nodes. We 1) mathematically
define the attack model, 2) identify thousands of empirical instances of this
similar attack in the wild, 3) empirically measure the model parameters from
our two monitoring nodes, and 4) conduct attack simulations on the local
network to compare its performance with existing Denial-of-Service attacks. We
show that an attacker can amplify network traffic at modified nodes by a factor
of 3,600, and cause economic damages 13,800 times greater than the amount
needed to carry out the attack. Despite these risks, aggressive latency
reduction may still be profitable enough to justify the existence of modified
nodes. To assess this trade-off, we 1) simulate the transaction validation
process in the local network and 2) empirically measure the latency reduction
by deploying our modified node in the Ethereum testnet. We conclude with a
cost-benefit analysis of skipping validation and provide mitigation strategies
against this attack.
