Describes the problem of fork choice and finality in Ethereum PoS, the relevance of Single Slot Finality (SSF) as a possible improvement to network finality, and demonstrates a working prototype—SlotZ
1. Introduction
1.1 Context
Since Ethereum's transition to Proof of Stake (Beacon Chain), the underlying fork choice logic (LMD GHOST) and finality mechanism (Casper FFG) have become the foundation of chain security. LMD GHOST (Latest Message Driven — Greediest Heaviest Observed Subtree) determines the chain's head based on the latest messages (votes) from validators. This classic behavior results in finality occurring with a lag (usually in the next slot or later), which creates delays in transaction confirmation, impacts user experience, and complicates reliable cross-chain interactions.
1.2 Problem
Fork attacks and network desynchronizations can create contentious branches.
Delayed finalization reduces speed and UX, and complicates instant settlement (L2, bridges).
There is no simple interactive environment where one can visually see the interaction of LMD GHOST, quorum, and SSF under real network conditions and validator failures.
1.3 Target
To demonstrate and prove whether and how the conceptual SSF—block finalization in the same slot—is feasible given the correct LMD GHOST logic and sufficient network stability. The project provides an interactive tool for exploring scenarios: network delays, forks, validator failures, and attacks.
https://docsend.com/v/f4zp9/slotzero
A fully working prototype has been completed.
In Progress