Why there’s a 100 block maturity level

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“People don’t seem to grasp the nature of the block maturity level,” says Dr. Craig S. Wright in this week’s episode of “Bitcoin Class with Satoshi.” In this ongoing weekly series with sCrypt founder Xiaohui Liu, Dr. Wright talk more about miner (transaction processor) incentives and how Bitcoin‘s economic rules help to keep the system honest.

He’s referring to the rule in the Bitcoin protocol that enforces a 100-block maturation before a processor’s 6.25-Bitcoin (currently) block subsidy can be spent. Once 100 blocks have passed after a block is processed, processors usually spend the money by paying for overheads and/or sending it to an exchange. Those “coinbase” coins then begin to circulate among other users, creating multiple transaction streams and solidifying the coinbase transaction’s integrity by adding more data to the blockchain.

Ep11: 100 Block Maturity Level here https://t.co/okTUue9qQrhttps://t.co/t50fWslykM#bitcoinclass

— sCrypt Official | OP_CAT 🐱 (@scryptplatform) July 20, 2021

The 100-block number is to cater to chain reorganizations that occur either naturally, or less frequently, in the event of an attack. Dr. Wright explains that 100 blocks take roughly 16-17 hours to confirm, giving enough time for miners in various timezones to discover and react to a problem.

He then goes into some detail about what would happen if anyone tried to attack the network (that is, perform a dishonest or illegal action) past that point. Any mining operation with enough power to even consider such an attack would be a sizeable operation, ultimately beholden to some authority. Even if it existed physically within a jurisdiction that didn’t cooperate with international norms, that entire jurisdiction could be forked off the network.

Why are we talking about this again? Because in recent times, the concept or a “reorg attack” and the much-discussed Bitcoin thought experiment of “selfish mining” have been prominent in the news. Dr. Wright says he’s explained several times in the past that selfish mining (where a miner secretly mines a long enough block to create a dishonest majority-hashpower chain) isn’t effective. It wouldn’t go unnoticed, and other miners would not simply sit by and allow it to happen without taking action.

A selfish miner would need to continue their action over several thousands of blocks to make a profit, covering more than one difficulty adjustment period—and this is simply impossible on a network with so many other major economic participants. Processors/miners, exchanges, merchants, business users—all have something large at stake and all have the means to seek redress, either legal or via the network’s rules. He promises to elaborate further on how other nodes could detect an attack in future episodes.

Dr. Wright ties this in once again with Lawrence Lessig’s statement “code is law,” that many have erroneously applied to Bitcoin and continue to do so today. “Bitcoin is not designed to represent ‘code is law,'” he says, and anyone who repeats the phrase without understanding other factors external to the code “is a moron.”

“I’m being nice here. I could say far worse things.”

Similarly, claims that machines and their code are capable of anything approaching general intelligence are equally wrong. “The most intelligent algorithm (that exists today) is not as smart as a spider,” he says. In fact, a spider has exponentially more computational complexity than every computer system in the world. And if you think we’re getting closer to creating a general intelligence every day, that’s also wrong. We’re as close to that as a caveman was, millions of years ago. Self-driving cars may get it right 90% of the time, but fail at the other 10%, making them near-useless.

Why is this relevant? It teaches us never to place too much faith in code. “Code is not law. Code is simple, and code is easy to attack.” Additionally, no system exists outside the law, and you can’t create a system (or club) that exempts itself from laws.

Dr. Wright speculates that BTC Core developers have other reasons for deliberately keeping Bitcoin small, limited and niche. It serves other purposes that way, he says. What could they be? You’ll have to watch the full episode to find out.

The original Bitcoin protocol promotes openness and honesty, and the larger it gets, the more connections nodes have to other nodes, the more secure and honest it’s able to be.

To watch previous episodes of the Theory of Bitcoin and Bitcoin Class, check out the Theory of Bitcoin YouTube channel here and the Bitcoin Class with Satoshi YouTube channel here.