Blockchain 101: More Than Just Bitcoin

Previous: How Fintech Started the Revolution

If you think blockchain is just another word for Bitcoin, this post is for you. In the second chapter of his book, Pierluigi Martino peels back the curtain on what this tech actually is.

At its heart, blockchain is just a digital notebook (a “ledger”) that everyone in a network has a copy of. But it’s a very special notebook.

The Building Blocks

Why is it called a “blockchain”? Simple: transactions are grouped into blocks. These blocks are then linked together in a chain.

But here’s the cool part:

• It’s Distributed: Everyone has a copy. If one person tries to cheat, everyone else’s copy will show they’re wrong.
• It’s Decentralized: There’s no “boss” or central bank in charge. The network runs itself.
• It’s Immutable: Once something is written in the notebook, you can’t erase it or change it. It’s there forever.

How it stays safe

You might wonder how people trust a system with no boss. The answer is Cryptography. Banks use fancy math (like “hash functions”) to seal each block. If even one letter in a transaction changes, the “seal” breaks. It’s like a digital wax seal that’s impossible to fake.

They also use Public and Private keys. Think of your public key like your Venmo handle—anyone can see it to send you money. Your private key is like your password—you never share it, because it’s what lets you spend your money.

The “Agreement” Machine

Since there’s no boss, the network needs a way to agree on which transactions are real. This is called a Consensus Mechanism.

• Proof of Work (PoW): This is what Bitcoin uses. Computers solve super hard puzzles to earn the right to add a block. It’s very secure but uses a ton of electricity.
• Proof of Stake (PoS): A newer, greener way. Instead of solving puzzles, people “stake” their own money to prove they’re trustworthy.

Not All Blockchains are the Same

Martino breaks them down into three types:

1. Public: Anyone can join (like Bitcoin).
2. Private: Only invited people can join (banks love these because they’re faster and more private).
3. Hybrid: A mix of both.

The Big Picture

We’re currently moving through different “versions” of this tech:

• Blockchain 1.0: Just money (Bitcoin).
• Blockchain 2.0: Money + Smart Contracts (Ethereum).
• Blockchain 3.0: Everything else (Health records, voting, etc.).

Blockchain is a powerful tool, but it’s not perfect. It can be slow, and it’s still being figured out by governments. But the potential to cut out the “middlemen” is what has the banking world so nervous—and excited.

Next, we’re looking at how this tech actually gets used in the real world beyond just sending coins back and forth.

Next: Beyond Crypto: The Real Power of Smart Contracts

Book Metadata:

• Title: Blockchain and Banking: How Technological Innovations Are Shaping the Banking Industry
• Author: Pierluigi Martino
• ISBN: 978-3-030-70969-3