Proof of Chance: A Lightweight Consensus Algorithm for the Internet of Things
Mostefa Kara, Abdelkader Laouid, Mohammad Hammoudeh, Muath AlShaikh, Ahcène Bounceur
Abstract
This article is to propose a consensus algorithm, called Proof of Chance (PoCh), which is designed for the industrial Internet of Things (IIoT). The PoCh protocol is designed to be scalable and extensible, with a controllable conformance delay and low hardware and computation requirements. To reach a consensus, PoCh uses chance rather than computing power: “if condition <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$_{1}$</tex-math></inline-formula> , I am a candidate; if condition <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$_{2}$</tex-math></inline-formula> , I am the miner.” During every consensus iteration, the condition <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$_{1}$</tex-math></inline-formula> is updated, and a single miner is chosen using condition <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$_{2}$</tex-math></inline-formula> . Those conditions are randomized without the node generating any value and without assigning any weight to such value. The fault tolerance of PoCh is <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$5f/3 + 1$</tex-math></inline-formula> , meaning that PoCh can successfully achieve consensus as long as more than 40% of nodes are functioning properly, compared to 50% in the Proof of Stake (PoS) protocol.