Digital Dollar Bills: Understanding UTXOs and Change

Overview Have you ever looked at a transaction on a Bitcoin block explorer, and were confused by all the different amounts shown? Wondered what these “inputs” and “outputs” listed in the transaction mean? Bitcoin and other cryptocurrency transactions may seem similar in some ways to other digital payment mechanisms like debit cards or PayPal, but

Why Brainwallets are a Bad Idea

Overview Private keys are the most critical aspect of Bitcoin ownership – without them, you don’t truly own your Bitcoin! But in their raw form, private keys are a bit unwieldy. A bunch of random bits (256 to be exact) are not easy to remember or write down without error. Due to this problem, users

The Waiting Game: The Mempool and Transaction Fees

Overview Have you ever sent a Bitcoin transaction, only to panic and realize the money hasn’t shown up in the receiver’s wallet? Maybe you were sending from a mobile phone wallet to a hardware wallet or exchange, and became afraid that your money was lost! Don’t fret, you didn’t lose any money at all. Your

Indestructible Data: How Arbitrary Data is Added to the Blockchain

Overview The blockchain is a very powerful tool – it’s a distributed, immutable database of all the transactions that have ever occurred on a cryptocurrency network. When you transact on Bitcoin, for example, that transfer of value is recorded on the blockchain forever. It cannot be modified or changed after just a few confirmations (blocks

Prototyping the Blockchain Lawnmower (Code Companion #3)

Overview In my recent tutorial on tokenization, I showed a possible future where we might trade assets like homes, cars or even lawnmowers on the blockchain. I built a fun prototype to demonstrate this concept – using a Bitcoin Cash token, a Raspberry Pi, and my trusty lawn tractor! This tutorial is a technical look

Hands Off My Keys! The Basics of Offline Wallets

Overview In the cryptocurrency world, ownership of your money is controlled by cryptographic private keys. These keys are used for deriving your receiving addresses and ultimately for spending funds. For obvious reasons, secure storage of these keys is absolutely critical for any Bitcoin user, as anyone with the keys can control the funds at that