BIP-361: Post Quantum Migration and Legacy Signature Sunset. The proposal: five years after activation, any bitcoin not migrated to quantum-resistant addresses gets frozen.
The numbers behind the proposal. As of March 1, 2026, more than 34% of all existing bitcoin had public keys exposed on-chain. According to @Jameson Lopp, one of the six signatories, the technically vulnerable bitcoin total 5.6 million. Roughly 28% of the circulating supply. That figure includes 1.1 million bitcoin untouched since 2010, probabilistically attributed to Satoshi Nakamoto.
The proponents’ thesis: if an attacker with a sufficiently powerful quantum computer unlocked those UTXOs and dumped them on the market, the sell-off would hurt every other holder. From the BIP text: “Lost coins make everyone else’s worth slightly more. Coins recovered by an attacker make everyone else’s worth less. Consider it theft from everyone.”
Lopp himself, however, in the hours after the debate blew up on X, stated: “At the moment, I don’t think any of this is necessary.”
The objections come from several directions. @MartyBent raised what he calls “the man in the coma” case: anyone who fails to execute the migration for five years loses all their money, frozen by consensus rules. @Adam Back at Paris Blockchain Week called today’s quantum computers “lab experiments” with “incremental” progress, and argued that Bitcoin can prepare itself through optional upgrades without imposing freezes.
The real point is something else. If consensus rules can freeze addresses based on type, a precedent exists. Governments will have it on the table: freezing sanctioned UTXOs, freezing addresses on OFAC lists, freezing the wallets of politically inconvenient people.
The proposal calls for freezing legitimately held bitcoin in the name of the collective good. Bitcoin exists because no one can block anyone else’s funds. BIP-361 asks the protocol to do exactly that, by design.
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The numbers behind the proposal. As of March 1, 2026, more than 34% of all existing bitcoin had public keys exposed on-chain. According to @Jameson Lopp, one of the six signatories, the technically vulnerable bitcoin total 5.6 million. Roughly 28% of the circulating supply. That figure includes 1.1 million bitcoin untouched since 2010, probabilistically attributed to Satoshi Nakamoto.
The proponents’ thesis: if an attacker with a sufficiently powerful quantum computer unlocked those UTXOs and dumped them on the market, the sell-off would hurt every other holder. From the BIP text: “Lost coins make everyone else’s worth slightly more. Coins recovered by an attacker make everyone else’s worth less. Consider it theft from everyone.”
Lopp himself, however, in the hours after the debate blew up on X, stated: “At the moment, I don’t think any of this is necessary.”
The objections come from several directions. @MartyBent raised what he calls “the man in the coma” case: anyone who fails to execute the migration for five years loses all their money, frozen by consensus rules. @Adam Back at Paris Blockchain Week called today’s quantum computers “lab experiments” with “incremental” progress, and argued that Bitcoin can prepare itself through optional upgrades without imposing freezes.
The real point is something else. If consensus rules can freeze addresses based on type, a precedent exists. Governments will have it on the table: freezing sanctioned UTXOs, freezing addresses on OFAC lists, freezing the wallets of politically inconvenient people.
The proposal calls for freezing legitimately held bitcoin in the name of the collective good. Bitcoin exists because no one can block anyone else’s funds. BIP-361 asks the protocol to do exactly that, by design.
naddr1qqjk...
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