Special thanks to Sacha Yves Saint-Leger Danny Ryan Please see their reviews.
In This article will take a look at the consensus algorithms that are used to power Ethereum 2.0. Ethereum 2.0 uses a unique approach to decide which blocks are the head and which ones are the tail of the blockchain. Is that so? Y They are One part of the process.
By Combining these two mechanisms, Ethereum 2.0 seeks to achieve a consensus that is fast, secure, and reliable in normal network conditions, but also secure when under attack.
The Trilemma
FLP Impossibility Distributed computing has a central finding that distributed computing is impossible. simultaneously The system should not rely on any unreasonable assumptions.
Safety It is the belief that decisions cannot be undone. Vitality This is the idea that new decisions are possible. Protocol is asynchronous Without a message size limit, it will be delivered.
If Nodes could communicate consistently, follow protocol strictly, and never fail to reach consensus, it would be simple. But that’s not the way the world works. When These assumptions are false, FLP Impossibility It is a sign that at least one: safety, vibrancy, and total synchrony must be compromised.
GHOSTs, their opinions, and forks
Uses Ethereum 2.0 Greedy Heavier Observed SubTree (GHOST) As the fork selection rule. GHOST determines which branch has the most votes. It does this by weighing all votes for each block in the tree.
In Other wordsGHOST selects the side on which the most recent messages support the block’s subtree, i.e. the block or one its descendants, for each branch. The algorithm continues this process until it reaches an empty block.
GHOST has the advantages of reducing attacks that occur during high network latency periods, and minimizing the depths of chain reorganizations compared to the longest chain rule. This This is because an attacker can keep the blocks in their chain efficiently, making it the longest. However, GHOST would prefer the other fork since it has more votes.
In Particular, Ethereum 2.0 utilizes a GHOST variation that is adapted to a PoS environment called Latest Message Driven GHOST (LMD–GHOST). The LMD-GHOST’s idea is that one should only take into account the head when calculating the length of the string. The newest Each validator casts the vote, not any votes from the past. This This greatly reduces the amount of computation needed to execute GHOST. The number of validators ($O(v),$) cannot be greater than the number required for branch selection. Big O notation).
Under Under GHOST rules, validators/miners have the right to add a block to the Blockchain (lifetime) and can do so at any stage in the chain’