Paper 2025/1719 Original: eprint.iacr.org/2025/1719 ↗

Bribers, Bribers on The Chain, Is Resisting All in Vain? Trustless Consensus Manipulation Through Bribing Contracts

Bence Soóki-Tóth
István András Seres
Kamilla Kara
Ábel Nagy
Balázs Pejó
Gergely Biczók
Abstract

The long-term success of cryptocurrencies largely depends on the incentive compatibility provided to the validators. Bribery attacks, facilitated trustlessly via smart contracts, threaten this foundation. This work introduces, implements, and evaluates three novel and efficient bribery contracts targeting Ethereum validators. The first bribery contract enables a briber to fork the blockchain by buying votes on their proposed blocks. The second contract incentivizes validators to voluntarily exit the consensus protocol, thus increasing the adversary's relative staking power. The third contract builds a trustless bribery market that enables the briber to auction off their manipulative power over the RANDAO, Ethereum's distributed randomness beacon. Finally, we provide an initial game-theoretical analysis of one of the described bribery markets.

Metadata
Available format(s)
PDF
Category
Cryptographic protocols
Publication info
Preprint.
History
2026-01-12: last updated
2025-09-21: published
Short URL
https://ia.cr/2025/1719
License
https://creativecommons.org/licenses/by/4.0/

BibTeX

@misc{cryptoeprint:2025/1719,
      author = {Bence Soóki-Tóth and István András Seres and Kamilla Kara and Ábel Nagy and Balázs Pejó and Gergely Biczók},
      title = {Bribers, Bribers on The Chain, Is Resisting All in Vain? Trustless Consensus Manipulation Through Bribing Contracts},
      howpublished = {Cryptology {ePrint} Archive, Paper 2025/1719},
      year = {2025},
      url = {https://eprint.iacr.org/2025/1719}
}
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