Adversarial procurement in blockchains

A new arXiv paper by Maryam Bahrani, Michael Neuder, and S. Matthew Weinberg tackles a fundamental challenge in emerging blockchain protocols: how to efficiently purchase expensive computational work, such as generating cryptographic validity proofs (e.g., SNARKs), in a pseudonymous, adversarial environment. The authors formalize this as a mechanism design problem where the protocol must balance the economic cost of a liveness fault (work not completed) against the payments needed to incentivize participants. Their key result: the loss of the optimal protocol scales logarithmically in the cost of a liveness fault, scaled up by the adversarial fraction of the network. This logarithmic scaling is surprisingly efficient compared to naive approaches.

The paper also identifies an intuitive optimal equilibrium structure that offers concrete guidance for practitioners. In many regimes, the optimum designates a single random node as the primary worker, with a committee serving as a fallback—reminiscent of leader-based consensus. Additionally, the authors characterize asymptotic regimes where negative payments (slashing in blockchain parlance) provide significant benefits. This work directly impacts protocols that use zero-knowledge proofs, rollups, or any verification asymmetry, helping developers design more robust and cost-effective incentive mechanisms for decentralized task procurement.