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arXiv · 2402.01363

Bribe & Fork: Cheap Bribing Attacks via Forking Threat

Zeta Avarikioti·Paweł Kędzior·Tomasz Lizurej·Tomasz Michalak
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Abstract

In this work, we reexamine the vulnerability of Payment Channel Networks (PCNs) to bribing attacks, where an adversary incentivizes blockchain miners to deliberately ignore a specific transaction to undermine the punishment mechanism of PCNs. While previous studies have posited a prohibitive cost for such attacks, we show that this cost may be dramatically reduced (to approximately \$125), thereby increasing the likelihood of these attacks. To this end, we introduce Bribe & Fork, a modified bribing attack that leverages the threat of a so-called feather fork which we analyze with a novel formal model for the mining game with forking. We empirically analyze historical data of some real-world blockchain implementations to evaluate the scale of this cost reduction. Our findings shed more light on the potential vulnerability of PCNs and highlight the need for robust solutions.

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Zeta Avarikioti, Paweł Kędzior, Tomasz Lizurej, Tomasz Michalak. 2024-07-17. Bribe & Fork: Cheap Bribing Attacks via Forking Threat. https://arxiv.org/abs/2402.01363

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