The deadline to freeze Satoshi

For two years the quantum threat to Bitcoin was an attack-side number — how few qubits it would take to forge a signature and drain a wallet. The defense was hand-waving. As of this spring it has dated paperwork. BIP-360, merged into Bitcoin's proposal repository in February, adds a new quantum-resistant address type. Its quieter companion, BIP-361 from April, is the one that matters: it proposes a deadline after which the network stops honoring spends from the old, vulnerable address types altogether.

Making Bitcoin quantum-safe requires breaking its founding promise: that a coin, once yours, is yours irreversibly and forever.

That second proposal is where the upbeat progress narrative goes silent. Around a third of all bitcoin — by Coinbase's own advisory board, some 6.5 to 6.9 million coins — sits in addresses whose public keys are already exposed and would be trivially drained by a working quantum computer. Among them are the roughly one million coins widely believed to be Satoshi Nakamoto's, untouched since 2010 and held by no one who can move them to safety. The only way to stop a future attacker from stealing those coins is to freeze them first: pick a date, and after it, they are gone for everyone, permanently.

This is often framed as an open gap with no clear remediation path. It is neither — it is a published, deliberate proposal, and the reason it is explosive is that it forces a choice Bitcoin was built to never make. Protecting the network from quantum theft means voting to make a third of the supply unspendable, breaking the founding promise that coins are absolute, irreversible property. The migration's real cost isn't engineering. It's deciding whose money stops existing.