New Bitcoin Proposal Would Freeze Coins to Counter Quantum Threat
A new Bitcoin proposal would phase out the network's existing signature schemes and freeze coins that fail to migrate in time to counter the threat of quantum computing.
Dubbed BIP-361, the proposal was updated by co-author Jameson Lopp and five other developers in Bitcoin's official improvement proposal repository on Tuesday. Quantum attacks are a theoretical method of using advanced computers to derive private keys from public keys exposed on a blockchain, potentially giving an attacker control of a wallet without the owner's credentials. The moment when a quantum computer emerges with sufficient power to break today's encryption is often called "Q-Day."
BIP-361 lays out a three-phase timeline: blocking inflows to vulnerable addresses roughly three years after activation, and a total freeze on such addresses after five years. It also includes an "escape hatch" using zero-knowledge proofs for holders who miss the deadline, allowing them to prove ownership without exposing their vulnerable keys.
Over 34% of all Bitcoin has exposed a public key on-chain, according to the proposal, leaving those funds vulnerable to theft by a sufficiently powerful quantum computer. BIP-361 remains in draft status with no activation timeline and depends on BIP-360, a separate quantum-resistant transaction framework still under review.
Security costs Earlier in March, Google published a formal timeline to transition its infrastructure to post-quantum cryptography by 2029, calling the threat a "decade-scale problem." Bitcoin has historically treated a valid signature as “sufficient proof of control,” regardless of the underlying math's security. BIP-361 would change that by treating quantum-vulnerable signatures as deprecated.
The new proposal “shifts quantum risk from 'maybe I get robbed later' to 'if I miss the deadline, I lose everything',” according to some observers. But not everyone agrees the tradeoff is warranted. Frederic Fosco, co-founder of Bitcoin metaprotocol OP_NET, noted that the proposal appears to turn Bitcoin's founding promise on its head by introducing a protocol-enforced freeze.
A protocol-enforced freeze If adopted, BIP-361 would effectively mean that any coins still secured solely by ECDSA signatures would become unspendable after the five-year window. However, proponents argue that an unprotected chain's price would collapse the moment a quantum theft is demonstrated, as trust in the underlying math would vanish.
Bitcoin's decentralized governance is seen as a strength in normal times but a potential weakness when racing against a technological clock. In a tweet, Jameson Lopp conceded, “I know folks don't like BIP-361. I don't like it myself. I wrote it because I like losing all my Bitcoin even less.”
