From 7ba712ba60a3ced7613eb47e8fcf7418ed2bb13f Mon Sep 17 00:00:00 2001
From: "mia von steinkirch, phd"
 <1130416+miavonsteinkirch@users.noreply.github.com>
Date: Thu, 17 Nov 2022 12:58:12 -0800
Subject: [PATCH] =?UTF-8?q?=F0=9F=AB=91=20Visualising=20the=207-block=20re?=
 =?UTF-8?q?org=20on=20the=20Ethereum=20beacon=20chain?=
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---
 ...per-ffg.md => pos_consensus_mechanisms.md} | 30 ++++++++++++++++++-
 1 file changed, 29 insertions(+), 1 deletion(-)
 rename NODES_on_Ethereum/{casper-ffg.md => pos_consensus_mechanisms.md} (53%)

diff --git a/NODES_on_Ethereum/casper-ffg.md b/NODES_on_Ethereum/pos_consensus_mechanisms.md
similarity index 53%
rename from NODES_on_Ethereum/casper-ffg.md
rename to NODES_on_Ethereum/pos_consensus_mechanisms.md
index afd50ee..b6eb080 100644
--- a/NODES_on_Ethereum/casper-ffg.md
+++ b/NODES_on_Ethereum/pos_consensus_mechanisms.md
@@ -1,7 +1,26 @@
-## 🍺 Casper FFG
+## Consensus mechanisms in PoS in Ethereum
+
+>Proof-of-Stake Ethereum features two consensus mechanisms running in parallel, FFG Casper and LMD GHOST.
 
 <br>
 
+
+### casper FFG
+
+* responsible for providing economic finality to the chain.
+* when a checkpoint block (the start of an epoch) accumulates enough target votes, it becomes justified. When a recently justified source is used to justify a target checkpoint, the target checkpoint is justified and the source becomes finalised. no conflicting checkpoint block can be also finalised without at least 1/3 of the active stake getting slashed. there can be no re-org of the finalised chain without a massive loss of ETH by some party.
+
+<br>
+
+### LMD GHOST
+
+* provide a dynamically available ledger - grow the chain while finalisation runs. headers in this chain accumulate weight by the head vote from attesters. the weight is used to figure out which branch the validator should follows if a fork happens.
+
+
+<br>
+
+### lexicon
+
 * block trees: if ethereum gets out of sync (network latency, deliberate attack, etc.), the blockchain can quickly become a block tree. validators need a method to choose a branch and identigy a single canonical blockchain.
 * checkpoint: a block every N blocks.
 * root: always justified and finalized.
@@ -13,3 +32,12 @@
 * validators must not publish two distinct votes such that 1) are the same height of the block tree, 2) overlapping votes.
 * validators that break the casper voting rules are slashed: a portion of that validator stake is destroyed and the validator is removed from the network.
 * validators have a responsibility to vote, failing to broadcast a vote will result in a small penalty, slowly draining the validators stake.
+
+<br>
+
+
+<br>
+
+### resources 
+
+* [Visualising the 7-block reorg on the Ethereum beacon chain](https://barnabe.substack.com/p/pos-ethereum-reorg?s=w)