PoS Consensus Cheatsheet

Cheatsheet about PoS two classes: 51% and 2/3

Alexandr Fadeev

• 1 min read
PoS Consensus Cheatsheet

First and foremost

stake = voting power

It applies to any Proof-of-Stake protocol.

Then, it is how the voting power is utilized and how the network defines consensus on what is right and what is not.

And there are at least 2 classes of PoS.

  1. PoS with PoW-style forking and probabilistic finalization, aka "51%" fork choice rule in Ethereum's consensus.
  2. More often, popular consensus protocols follow the BFT's "2/3" rule: https://fadeevab.com/why-2-3/
Why 2/3?
... is the minimum number of honest voters in PoS + BFT consensus protocols? (With infographics at the bottom).
Alexander Fadeev's BlogAlexandr Fadeev

PoW-style forking is more suitable for the most decentralized networks with thousands of participants, higher latency, and lower censorship – forks appear when delays occur.

BFT stands for Byzantine Fault Tolerance. It's a pretty much universal rule under the hood of many protocols with a small number of malicious nodes. It is used for fast consensus, where the set of validators is well-defined, and everyone votes on a block within a short time slot. It's suitable for the smaller networks for lower latency, but it tends to have a higher participation barrier.

Cheers!