01 - Intro

Overview

Blockchain

it is not the invisible technology that’s changing the world
open ledger that can record transactions between two parties efficiently
- transactions: blocks
a copy of blockchain is distributed to every node
consensus is achieved through dedicated algorithms
executing user-defined scripts (smart contacts)

THE BLOCKCHAIN IS NOT A DATABASE: it is a TRANSACTION LIST

transfer of assets from account A to B
accounts are numbers: we don’t care about people or characteristics!
- but to make sure to verify the person, we could use some methods: the account
  - signature: proof that someone is authorized to do and to do this they have a special private key they only have that identify himself
EOA Accounts: they are external: bots, systems… whatever

EVERY TRANSACTION IS UNIQUE

Totally order: every transaction is up or above another The order matters!

this is done to avoid Double spending problem
- 🔼 Revise the Double spending problem 📅 2023-09-27 ✅ 2023-10-14

Blocks group and collate transactions → they are time units → as far as transactions grow as long as block are produced
the order matters as well!
the blocks are regularly updated: the head contains meta-information about the other blocks
a wallet is a lightweight client that fetches only blocks it’s interested to

Blockchain IS DECENTRALIZED: there is not any “official” server, it is just a protocol.

The time of transactions doesn’t determine the order of the transactions!

We don’t decide if it’s true or false → the network decides! The blockchain saves data in a permanent way.

Before doing any transaction, the network needs to confirm this transaction.
For this reason, transactions are slow.
A transaction has more probability to enter into a block if it promises more fee!
- BTC: also free
- ETH: it’s not

if you want to be a book publisher fair, but prove me you care about books
- crypto-puzzle: if you win, you’re entitled to distribute new blocks
- you will be rewarded!

There is a new amount of BTC circulating on every new block

The minining pool is a cluster of nodes that solves crypto puzzles together. PoW is a protocol that dictates if you win or not.

Smart Contracts are pieces of code.

Smart Contracts are mere pieces of code.

They have no random function, and are turing-complete (deterministic). They can do whatever because they are codes!

They live in the ETH layer.

They execute a function when called!

They are mainly used for GAMBLING!

An account can invoke Smart Contracts. Not the other way!