Where are your coins?

Understanding the metaphor of Bitcoin. A brief introduction to bitcoin for developers.

About me

• My name is Jason, but you can call me Jay
• I love open source software, bitcoin, and linux
• Contract Programmer since 2019
• Contact me:
  • Github: @jasonribble

Pre-requisites

• Bitcoin is a peer-to-peer electric cash system
• Let's pretend it's $0 per coin today.
• What is money? Monetary Theory
• Macro economics
• Energy section conversation
• If we have extra time and exhausted technical questions, then we can talk big picture
• Legal disclaimer

Objective

• To see what the underlying technical metaphor of Bitcoin.
• When talking about bitcoin, we use metaphor to make it more human meaningful.
• (Hidden agenda: Confuse you to incite curiosity)

Zooko's triangle

Metaphors in Computer Science

In computer science, we talk in abstractions for simplicity.

This help us by allowing for additional complexity, but with a tradeoff.

What are some examples of this?

Mac now supports Windows

Who has send & receive bitcoin before?

• Can someone describe how I can send them bitcoin step-by-step?
  • Talk in human meaningful ways
• Where are your coins?

Quote from Mastering Bitcoin

"In bitcoin, there are no coins, no senders, no recipients, no balances, no accounts, and no addresses. All those things are constructed at a higher level for the benefit of the user, to make things easier to understand." - Ch 10, Mastering Bitcoin by Andreas Antonopoulos

So, what is cryptocurrency?

• crypto = hidden (Latinized Greek)
• cryptography = writing in secret characters
• cryptocurrency = hidden currency?
• Very little encryption in bitcoin

Core cryptography in bitcoin

• We'll focus on two forms of applied cryptography in bitcoin
• What is a core element of cryptography?

Asymmetry

• Easy to do one way
• Hard to reverse it
• What's an example of this? Non-technical answers are acceptable
• Why is asymmetry important?

Miners = Hashers

• What is a hash?
• What is Proof of Work?
• What is the purpose of mining?
  • Why do we need it?

DigDug Miner

Miners = Hashers (cont.)

“The purpose of mining is not the creation of new bitcoin. That’s the incentive system. Mining is the mechanism by which bitcoin’s security is decentralized.” - Mastering Bitcoin

Wallets = Signers

• What are keys?
  • What is a public key?
  • What is a private key?
  • What is a bitcoin address?
• What are signatures?

Wallets = Signers (cont.)

• Fun fact: since private keys are 256 bits, that means there are 2^256 different possibilities.
• "There are as many possible private keys in Bitcoin s there are atoms in a billion galaxies" - Programming Bitcoin by Jimmy Song

Public key exchange

Some demos

• Overly Simplified Python Mining Demo
• How a (modern) bitcoin address is generated

Where can you learn more?

• AZ Bitcoiners
  • Started in 2020
  • Meets twice a month
    • one non-tech
    • one tech (Phoenix BitDevs)
  • Phoenix Nostr also has a lot of shared groups