COCP: Blockchain Proof-of-Useful-Work Leveraging Real-Life Applications

Abstract

We propose Combinatorial Optimization based Consensus Protocol (COCP) that considers efficient use of energy in Blockchain (BC) consensus protocol based on Proof-of-Useful-Work (PoUW) concept. Instead of classical cryptographic puzle, it involves dealing with hard real-life combinatorial optimization (CO) problems submitted by BC participants called customers. Two sources of rewards are provided for miners, one related to adding a new block and the other for solving an instance of CO problem. The main issues that arise when combining BC and CO, are security and consistency of maintaining the whole system. We discuss how to resolve them and what are the benefits of the proposed COCP for all BC participants. Our proposed doubly-rewarding scheme and efficiency in energy exploration are illustrated on a small example from the Ethereum BC network.