PoW blockchain denial-of-service attack becomes self-sustaining and profitable
PDoS: A Profitable Denial-of-Service Attack against Proof-of-Work Blockchain Liveness
Cryptography and SecurityComputer Science and Game Theory
Summary
Proof-of-Work blockchains depend on miners acting in their own economic interest to keep the system running smoothly. The authors discovered a new kind of attack called PDoS that not only disrupts the blockchain’s ability to add new blocks but also earns money during the attack, making it cheaper or even profitable for attackers. This is surprising because usually attackers lose money when trying to disrupt blockchain networks. Their work shows that when block rewards or transaction fees are high, these attacks become easier to sustain and more dangerous.
What this means in practice
- •For blockchain developers: Design incentive mechanisms and protocols to prevent economically sustainable denial-of-service attacks on PoW blockchains.
- •For blockchain network operators: Monitor mining pool behaviors and economic signals to detect and mitigate PDoS-style attacks threatening network liveness.
Authors
Junjie Hu, Tianzhu Han, Na Ruan
Abstract
The security and liveness of Proof-of-Work (PoW) blockchains fundamentally depend on the economic rationality of miners. Existing incentive-driven denial-of-service attacks, such as BDoS, can deter rational miners from participating, but require the attacker to continuously absorb substantial economic losses and are therefore difficult to sustain in high-value networks. Meanwhile, prior infiltration-based withholding attacks are designed to extract revenue rather than to directly disrupt chain liveness. We present PDoS, a hybrid attack that combines block header signal deterrence with parasitic revenue extraction. PDoS disrupts blockchain liveness while exploiting the victim pool's share-reward mechanism to subsidize the attack cost, thereby lowering the adversarial hash-power threshold required to induce rational miners to shut down. We further show a counterintuitive result: in high-fee or high-MEV environments, higher block value can make PoW systems less secure by increasing the attacker's parasitic revenue and pushing the attack across the break-even point into a self-sustaining, or even profitable, regime. To the best of our knowledge, PDoS is the first attack to demonstrate that disrupting PoW blockchain liveness can be economically self-sustaining and even profitable.