I read the documents for @BabylonLabs_io for the first time, and there was one word that really stumped me.
Finality.
The most counterintuitive thing about Bitcoin in these 17 years is that it actually doesn’t truly have finality. Six confirmations, a hundred confirmations—on paper, all of that can still be replaced by a longer chain. Satoshi Nakamoto wrote for probabilistic security, not absolute finality.
So what exactly is the Finality Provider in Babylon providing?
The more I read, the more I realized the question is backwards.
A Finality Provider isn’t adding finality to Bitcoin. It’s adding finality to the PoS chain that’s attached to Bitcoin. BTC still follows its own probabilistic rules, but once the Finality Provider’s signatures fall, this segment of PoS chain history gets “pinned” to Bitcoin’s timestamp. Want to roll back? The attacker would first have to convince all Finality Providers to abandon the BTC they’ve locked.
I paused here and thought about it for a long time.
Turns out Babylon didn’t add a new function to Bitcoin. It lets Bitcoin lend out its existing attributes. Bitcoin’s timestamp is the most expensive timestamp in the world—guarded by hundreds of EH/s of hashing power. What Babylon does is to let this timestamp be rented by an external PoS chain.
Self-reflection: people with heavy Ethereum background (I count myself) tend to apply Casper’s finality directly and assume finality is an in-chain consensus rule. But here in Babylon, finality is a cross-chain primitive—it's a service that can be rented. If you don’t get around this difference from the start, your understanding will go completely off track later.
In Lamport’s 1978 paper on distributed clocks, there’s a line that I think fits best here: the credibility of event ordering doesn’t depend on clock precision; it depends on whether all participants are willing to accept the same ordering authority.
Bitcoin is that authority. Babylon just rents it out.
The question is left to everyone—how many protocols have you seen the word “finality” in, and then assumed you understood it?
#baby $BABY
Finality.
The most counterintuitive thing about Bitcoin in these 17 years is that it actually doesn’t truly have finality. Six confirmations, a hundred confirmations—on paper, all of that can still be replaced by a longer chain. Satoshi Nakamoto wrote for probabilistic security, not absolute finality.
So what exactly is the Finality Provider in Babylon providing?
The more I read, the more I realized the question is backwards.
A Finality Provider isn’t adding finality to Bitcoin. It’s adding finality to the PoS chain that’s attached to Bitcoin. BTC still follows its own probabilistic rules, but once the Finality Provider’s signatures fall, this segment of PoS chain history gets “pinned” to Bitcoin’s timestamp. Want to roll back? The attacker would first have to convince all Finality Providers to abandon the BTC they’ve locked.
I paused here and thought about it for a long time.
Turns out Babylon didn’t add a new function to Bitcoin. It lets Bitcoin lend out its existing attributes. Bitcoin’s timestamp is the most expensive timestamp in the world—guarded by hundreds of EH/s of hashing power. What Babylon does is to let this timestamp be rented by an external PoS chain.
Self-reflection: people with heavy Ethereum background (I count myself) tend to apply Casper’s finality directly and assume finality is an in-chain consensus rule. But here in Babylon, finality is a cross-chain primitive—it's a service that can be rented. If you don’t get around this difference from the start, your understanding will go completely off track later.
In Lamport’s 1978 paper on distributed clocks, there’s a line that I think fits best here: the credibility of event ordering doesn’t depend on clock precision; it depends on whether all participants are willing to accept the same ordering authority.
Bitcoin is that authority. Babylon just rents it out.
The question is left to everyone—how many protocols have you seen the word “finality” in, and then assumed you understood it?
#baby $BABY