Ethereum 2.0

Why Replicate Data? (copy)

Reliability, Performance, Latency, Recovery

State Machine Replication (Total message Ordering)

• replicate State machine across servers

• execute same inputs

• execute in same order
  → consistent State Updates

Blockchain definition

public database updated and shared across many computers

Distributed Ledger Technology

Decentralized, Synchronized (common ledger)

Cryptographic Linking

• Immutable

• Hash changes → subsequent blocks become invalid

• restoring requires re-mining

Consensus Mechanisms

• Nodes must agree on same data

• must handle faulty or malicious actors

• must prevent double spending

Proof of Work

• computational Puzzle

  • hard to find

  • easy to verify

• requires massive computational power

Proof of Stake

• Validators lock up capital (stake) as collateral

• honest behaviour → rewards

• dishonest/lazy behaviour → slashing (destroying the stake)

Ethereum world computer

Purpose:

• Building apps and organizations

• Decentralized, premissionless, censorship-resistant

Ethereum Virtual Machine

Single, canonical Computer whose state everyone agrees on

• user broadcast request for computation

• every participant verifies, validates and executes the computation

• state changed is commited and propagated
  → Redundancy: not for speed but for trust, every node does everything

E

Ether & Gas

• Fees paid to execute transactions

• prevents infinite loops and spam

• Gas Limit * Fee per Gas

Smart Contracts

Is a program running on a ethereum Blockchain

• Immutable after deployment

• Automated → Runs as programmed, not controlled by user after deployment

• Account: Has a Balance and can receive transactions

• Code + Data: resides at a specific address