Zk-SNARK Marketplace with Proof of Useful Work (2510.09729v1)

Abstract: Proof of Work (PoW) is widely regarded as the most secure permissionless blockchain consensus protocol. However, its reliance on computationally intensive yet externally useless puzzles results in excessive electric energy wasting. To alleviate this, Proof of Useful Work (PoUW) has been explored as an alternative to secure blockchain platforms while also producing real-world value. Despite this promise, existing PoUW proposals often fail to embed the integrity of the chain and identity of the miner into the puzzle solutions, not meeting necessary requirements for PoW and thus rendering them vulnerable. In this work, we propose a PoUW consensus protocol that computes client-outsourced zk-SNARKs proofs as a byproduct, which are at the same time used to secure the consensus protocol. We further leverage this mechanism to design a decentralized marketplace for outsourcing zk-SNARK proof generation, which is, to the best of our knowledge, the first such marketplace operating at the consensus layer, while meeting all necessary properties of PoW.