Slot a la carte: Centralization Issues in Ethereum's Proof-of-Stake Protocol

János Tapolcai; Bence Ladóczki; Ábel Nagy

Paper 2025/219

Slot a la carte: Centralization Issues in Ethereum's Proof-of-Stake Protocol

János Tapolcai

, University of Technology and Economics

Bence Ladóczki, University of Technology and Economics

Ábel Nagy

, Eötvös Lóránt University

Abstract

In this paper, we demonstrate that Ethereum's current proof-of-stake (PoS) consensus mechanism poses a significant threat to decentralisation. Our research focuses on the manipulability of distributed randomness beacons (DRBs) in leader selection. Specifically, we show that RANDAO - Ethereum's DRB - is seriously vulnerable to manipulations in its current form. For example, if a lucrative slot is foreseen, there is a risk that staking entities may temporarily collude to control of the validators, enabling them to execute a series of RANDAO manipulation attacks that secure the target slot with a success rate. The effectiveness of our method stems from the fact that we work with a significantly richer model of the possible attacks compared to previous works. Our manipulative strategies work by missing blocks from the canonical chain - either by withholding blocks in the adversary's own slots or by forking out blocks proposed by others. We argue that while PoS can pave the path in the future for blockchains, Ethereum's current DRB implementation has to be replaced with a more secure mechanism.

Metadata

Available format(s): PDF
Category: Applications
Publication info: Preprint.
Keywords: blockchain cryptocurrency proof-of-stake ethereum strategic mining centralization
Contact author(s): tapolcai @ tmit bme hu
ladoczki bence @ vik bme hu
nagyabi @ gmail com
History: 2025-02-14: revised; 2025-02-13: received; See all versions
Short URL: https://ia.cr/2025/219
License: CC BY

BibTeX

@misc{cryptoeprint:2025/219,
      author = {János Tapolcai and Bence Ladóczki and Ábel Nagy},
      title = {Slot a la carte: Centralization Issues in Ethereum's Proof-of-Stake Protocol},
      howpublished = {Cryptology {ePrint} Archive, Paper 2025/219},
      year = {2025},
      url = {https://eprint.iacr.org/2025/219}
}