Chrisimos: A useful Proof-of-Work for finding Minimal Dominating Set of a graph

TL;DR

Chrisimos proposes a novel Proof-of-Work scheme that replaces hash computations with solving the minimal dominating set problem on graphs, aiming to reduce energy waste and provide practical utility.

Contribution

It introduces a new PoW protocol based on solving a real-life graph problem, with formal security proof and experimental validation of feasibility.

Findings

Feasible block interval times comparable to traditional hash-based PoW

Provides a decentralized solver for the minimal dominating set problem

Ensures security through a new chain selection rule

Abstract

Hash-based Proof-of-Work (PoW) used in the Bitcoin Blockchain leads to high energy consumption and resource wastage. In this paper, we aim to re-purpose the energy by replacing the hash function with real-life problems having commercial utility. We propose Chrisimos, a useful Proof-of-Work where miners are required to find a minimal dominating set for real-life graph instances. A miner who is able to output the smallest dominating set for the given graph within the block interval time wins the mining game. We also propose a new chain selection rule that ensures the security of the scheme. Thus our protocol also realizes a decentralized minimal dominating set solver for any graph instance. We provide formal proof of correctness and show via experimental results that the block interval time is within feasible bounds of hash-based PoW.