Technically Interesting Bitcoin Facts
When most people talk about Bitcoin, the conversation quickly shifts to price charts, trading strategies, or wild speculations about the next bull run. It’s all about profit, hype, and whether or not we’re in a “crypto winter.”
But what’s often overlooked is just how technically fascinating Bitcoin really is.
Behind the scenes, Bitcoin isn’t just a financial asset. It’s a beautifully engineered piece of software — and its architecture is packed with clever decisions, intentional limitations, and future-proofing strategies that deserve more attention than they get.
Here are a few of my favorite (simplified) technical facts about Bitcoin:
1. The Bitcoin Supply Limit Is Hardcoded
One of the most iconic features of Bitcoin is its 21 million coin cap — a hard limit on the total number of bitcoins that can ever be created.
But did you know this isn’t just a whitepaper idea or some vague protocol agreement? It’s literally hardcoded into the Bitcoin source code:
static const int64_t MAX_MONEY = 21000000 * COIN;
This value is baked into the core validation logic, and changing it would require a hard fork, which in Bitcoin’s conservative development ecosystem is an enormous and unlikely undertaking.
In other words, unless the majority of miners, developers, node operators, and exchanges all agreed to change this number — which they won’t — the cap is effectively immutable.
2. Millions of BTC Are Likely Lost — By Accident or Design
Bitcoin's fixed supply makes it scarce, but in reality, the available supply is even lower than most people think.
It’s estimated that between 3 and 4 million BTC are permanently lost due to human error: people throwing away hard drives, losing wallet passwords, or sending coins to unspendable “burn addresses.”
On top of that, there are over 11 million BTC that have been untouched since the very beginning — many of which are believed to have been mined by Satoshi Nakamoto during Bitcoin's early days.
Why mine and never move them?
One theory is that this wasn’t just hoarding — it was a deliberate security strategy. Back when the network was small and vulnerable, mining those coins may have helped establish computational dominance and prevent attacks — essentially, using economic weight to bootstrap trust in the system.
Whether lost by mistake or locked away intentionally, these missing coins reduce the effective supply, which has important implications for Bitcoin’s intrinsic value and long-term scarcity.
3. Bitcoin Is Intentionally Not Turing Complete
Most people assume that blockchains should be as powerful and flexible as possible. Ethereum embraced this by supporting a Turing-complete language, enabling it to run any kind of program, smart contract, or decentralized app.
Bitcoin, on the other hand, took a very different approach.
Its scripting language — Bitcoin Script — is intentionally Turing incomplete. This means:
- No loops
- No recursion
- No arbitrary execution
Why limit the power of the language? For security.
Turing-complete languages can be unpredictable. They allow for infinite loops, complex dependencies, and unpredictable gas consumption — all potential vectors for bugs and exploits. Ethereum has already seen multi-million dollar bugs due to the complexity of smart contract interactions (remember the DAO?).
By contrast, Bitcoin’s scripting is deliberately minimal. It’s closer to a stateless, stack-based execution environment — just enough to allow simple conditions like multi-signature wallets, timelocks, or hash-based constraints.
It can't run your DeFi protocol. But that's the point.
This minimalism drastically reduces the attack surface and makes Bitcoin easier to audit and reason about. And in the world of money, predictability is more valuable than flexibility.
4. Bitcoin Has an Exceptionally Strong Security Record
In the 15+ years since Bitcoin’s launch, its core protocol has maintained a remarkably strong security record — especially when compared to other major blockchains. Only a handful of serious bugs have ever been discovered, and none were exploited on the main network.
The two most notable incidents were:
2010 – Value Overflow Bug: A flaw in Bitcoin’s code allowed a single transaction to generate over 184 billion BTC — far above the 21 million cap. Developers patched the bug within hours, and the network was "rolled back" to erase the invalid coins.
Wait, didn't you just said the total supply is hardcoded at 21 million? Yes, that's true! This blog post explains it :)
2018 – Inflation Bug (CVE-2018-17144): A vulnerability in Bitcoin Core could have allowed attackers to create new coins by double-spending inputs within a block. The issue was reported responsibly, fixed quickly, and never exploited on mainnet.
These incidents stand out precisely because they are so rare. Overall, Bitcoin’s protocol has proven to be one of the most secure and resilient in the industry.
The development process is ultra-conservative. Every code change goes through rigorous peer review. Backward compatibility is treated as sacred. And perhaps most importantly: less complexity means fewer bugs.
5. A 51% Attack Is (Practically) Impossible
One of the theoretical attacks on proof-of-work blockchains is the so-called 51% attack, where a single actor (or colluding group) controls a majority of the mining power and can rewrite transactions.
But in Bitcoin's case, this is mathematically and economically unfeasible.
Bitcoin is, by far, the most powerful computing network on Earth, with a hashrate measured in hundreds of exahashes per second. To gain majority control, an attacker would need:
- Billions of dollars in mining hardware
- Access to cheap electricity at massive scale
- Enough time and resources to deploy and outpace the honest network
Even then, the economic cost would likely outweigh the potential gains — and the attack would destroy the value of the very asset they’re attacking.
In practice, Bitcoin’s decentralization and sheer size make it near-impossible to hijack.
6. The Genesis Block Has a Hidden Message
The very first Bitcoin block — the Genesis Block — was mined by Satoshi Nakamoto on January 3, 2009.
It contains a message that’s not part of the protocol, but embedded directly in the scriptSig of the coinbase transaction — a field miners can freely use for arbitrary data, and typically reserved for extra nonce values.
The message reads:
“The Times 03/Jan/2009 Chancellor on brink of second bailout for banks”
Technically, this text is encoded in hex and stored in the input of the transaction that generated the first 50 BTC reward — a reward that, by design, can never be spent.
This isn’t just a timestamp. It’s a powerful political statement — a reference to the global financial crisis and a subtle signal of why Bitcoin was created in the first place: as a decentralized alternative to bailout-driven banking systems.
In just one line, Satoshi immortalized Bitcoin’s origin story — both in purpose and in code.
7. “Not Your Keys, Not Your Coins”
This phrase has become almost cliché in crypto circles, but it’s technically — and philosophically — essential.
In Bitcoin, ownership equals control of the private key. If you don’t have the private key, you don’t actually own the coins — you’re relying on a middleman (exchange, custodian, wallet service).
That can be a risk or a convenience, depending on your perspective:
- If you're holding BTC on a centralized exchange, you're trusting that platform to remain solvent, secure, and ethical.
- If you're holding your own keys, you have full sovereignty — but you’re also 100% responsible.
This is the beauty and burden of true decentralization: ultimate freedom comes with ultimate responsibility.
But in a certain sense, Bitcoin fell victim to the very same ecosystem it was meant to challenge.
8. Quantum Computing Is a Threat — But Only If You’ve Spent Your Coins
Quantum computing is often cited as a potential existential threat to Bitcoin, because quantum algorithms (like Shor’s algorithm) could break the elliptic curve cryptography (ECC) used to secure wallets.
That’s not just a theory — it’s mathematically plausible.
But there’s a nuance here that most people miss: Bitcoin addresses don’t directly expose your public key.
Instead, the blockchain stores a hash of your public key, and the actual public key is only revealed when you spend the coins.
So here’s the key insight:
If your Bitcoin has never been spent, the public key has never been published — and quantum computers have nothing to attack.
This means that coins in cold storage, on never-used addresses, are quantum-safe for now. But once a transaction is made, that address becomes vulnerable — in a post-quantum world, that could matter.
That’s why Bitcoin developers are already researching quantum-resistant cryptographic schemes. It’s not an immediate danger — but the ecosystem is thinking ahead.
Conclusion
While headlines chase the price of Bitcoin, the real beauty lies in the protocol itself. Bitcoin isn’t just “digital gold.” It’s a masterpiece of software minimalism and security-first design.
Whether you’re a developer, a hacker, or just someone who appreciates elegant engineering — there’s a lot to admire beyond the price tag.
Until the next one,
Francesco