Last time I wrote about Bitcoin’s quantum problem, the story was about a technical fix. BIP-360, Pay-to-Merkle-Root, SHRINCS, the quiet work of replacing elliptic-curve signatures before a quantum computer makes them obsolete. I framed it as a governance problem dressed as cryptography.

I underestimated the governance part.

Since that article, the debate has moved from mailing lists to public combat. BIP-361, the proposal I mentioned only in passing, has become the lightning rod. Coinbase published a position paper on October 13 that effectively tells developers to stop arguing about the technical details and start planning the migration. Arthur Hayes went on The Rollup on October 17 and called the entire quantum threat “bullshit”. And the question sitting underneath all of it is the one nobody wants to answer on the record: what happens to the coins that never move?

BIP-361 Is Still a Draft. It’s Also Already a War.

BIP-361, titled Post Quantum Migration and Legacy Signature Sunset, is authored by Jameson Lopp and five co-authors. It outlines a phased transition away from ECDSA and Schnorr signatures, with a timetable that could eventually make legacy outputs unspendable through conventional transactions. It’s a draft. No activation date has been set. It depends on a separate post-quantum signature standard that doesn’t exist yet.

None of that has stopped the fight.

The core objection is property rights. Critics have called BIP-361 authoritarian and confiscatory, arguing it renders part of the UTXO set invalid and violates the network’s fundamental promise. Lopp himself has been careful, saying he doesn’t like the proposal and hopes it never needs to be adopted. But the draft exists, and in Bitcoin, a draft with a timetable is a signal.

The numbers explain why. Coinbase’s Quantum Advisory Council estimates roughly 1.7 million BTC sit in legacy pay-to-public-key addresses with fully exposed public keys. Roughly 1.1 million of those are attributed to Satoshi. At current prices, that’s north of $90 billion in coins that have never moved and may never move. BIP-361 doesn’t solve that problem. It just makes the problem visible.

Coinbase Plants a Flag

Coinbase published its technical blog on October 13, and it’s worth reading not for what it says about cryptography but for what it says about power. The company holds roughly 12% of all BTC in existence, according to its own blog. That’s not a stakeholder. That’s a systemic position.

The paper backs BIP-360’s container design, supports a 1-of-2 hybrid wallet that lets users spend with either a classic key or a quantum-safe key, and urges the community to start preparing before a cryptographically relevant quantum computer is confirmed. Coinbase estimates the migration could take up to seven years, and argues that waiting for certainty is a luxury Bitcoin can’t afford.

But the paper also draws a line that matters. Coinbase says debates over lost keys and abandoned wallets should be kept separate from the technical work. In my experience, that’s what a custodian says when it doesn’t want the Satoshi question to slow down the migration it needs for its institutional clients. It’s a reasonable position. It’s also a political one.

Hayes Says the Threat Is Overblown. He Has a Point, Sort Of.

On October 17, Arthur Hayes told The Rollup that the quantum threat is “bullshit,” a known and manageable risk rather than a reason to sell Bitcoin. His actual argument is more nuanced than the headline: he says most of the risk sits with people who reuse addresses and don’t practice basic wallet hygiene.

I think Hayes is half right. Wallet hygiene does matter. Address reuse is a real vulnerability. But “manageable” is doing a lot of work in that sentence. The coins that are most exposed are the ones that have never moved, the P2PK outputs from 2009 and 2010, and those owners aren’t practicing wallet hygiene because they’re gone. Hayes is answering a question about active users. The BIP-361 fight is about inactive ones.

The most capable known quantum machines still have fewer than 1,000 qubits, far short of what breaking elliptic-curve cryptography would require. That’s the strongest argument the skeptics have. But Bitcoin’s upgrade cycles are measured in years, not months. Lopp’s point, made back in December, still holds: a migration of this scale could take 5 to 10 years, so the preparation has to start before the threat is certain.

The Worst and Best Scenario

The Worst Scenario

Nothing gets done. The community spends another two years arguing about BIP-361’s property-rights implications while the actual post-quantum signature standard stays undefined. Coinbase’s seven-year timetable slips. A future quantum breakthrough catches Bitcoin with 30% of supply in exposed outputs and no coordinated migration path. The governance failure becomes the vulnerability.

The Best Scenario

The fight forces clarity. BIP-360 and BIP-361 get separated into what they actually are: one is an upgrade path, the other is a policy decision about abandoned coins. The mailing list traffic, already above 10% of technical communications, produces a concrete proposal that developers can actually review. Institutions like Coinbase and the newly formed Quantum Alliance push the ecosystem toward a standard, and Bitcoin does what it has always done: moves slowly, then all at once.

I don’t know which scenario wins. But I know the fight is no longer theoretical.

Summary

Since my last article, Bitcoin’s quantum debate has shifted from a technical conversation about BIP-360 to a political fight about BIP-361. Coinbase wants a phased migration and has the custody weight to push for one. Arthur Hayes thinks the panic is overblown and wants holders to focus on wallet hygiene. The developers are stuck in the middle, trying to design a cryptographic upgrade while the community argues about whether freezing Satoshi’s coins is a security measure or a betrayal. The quantum computer isn’t here yet. The governance crisis is.