Overview

Teaching: 10 min
Exercises: 0 min

Questions

• What is a Blockcahin?

• How is that related to a Bitcoin?

• What is a Smart Contract?

Objectives

• Understand the Blockchain ecosystem and history.

The blockchain is the distributed immutable database that drives cryptocurrencies and smart contracts. A series of transaction pools (blocks) connected by a hash pointer (chain).

Blockchain Ecosystem

Some key words that might come up:

• Bitcoin, Ethereum, Cardano, Hyperledger
• Cryptocurrency, (ERC) Token, NFT
• Solidity
• Smart Contracts
• Truffle, Ganace, Metamask, etherum remix, web3.js, infura.
• Wallets, addresses, hashes

Technology behind blockchain

• Public-key (asymmetric) cryptography
• Hash functions
• Merkel Trees
• Zero Knowledge Proofs

There are many blockchains

Bitcoin was the first after Satoshi Nakamoto solved the “Double-Spending” problem.

Hyperledger is a popular framework for developing new blockchain technologies that may be public, private (permissioned), or some hybrid implementation.

Mining is one way to validate all the transactions that have taken place on a network AND to reward participants who have done that computational work. So this is not strictly necessary for all blockchains.

From the original blocks mined: 1,148,800 BTC have never been spent (ref>).

Blockchain Explorer

Visit the blockchain at (https://etherscan.io/) or (https://www.blockchain.com/explorer) and see live transactions. Everything is stored in the ledger.

Uses for Blockchain

• Distributed finance
• Supply chain tracking
• Insurance
• Fraud and counterfeit authentication
• Idenity managment

What are we going to do today

• Write a contract in solidity.
• Deploy the contract to the (a) blockchain.
• Use the contract and watch the transactions be stored in the blocks.

Key Points

• A Blockchain is a decentralised database.

• Bitcoin was first, then many more

• Many tools are availble to interact with the blockchain ecosystem.