Binance founder Changpeng Zhao has proposed that Bitcoin’s community consider freezing dormant, quantum-vulnerable coins if their owners fail to move them after a future network upgrade to quantum-resistant cryptography.
Speaking during an interview with Galaxy Research head Alex Thorn, Zhao said the network could give holders of exposed coins a migration window of roughly six to 12 months. Addresses that remain unchanged after the deadline could then be blocked from spending through a protocol fork.
The proposal would apply to more than the wallets commonly linked to Bitcoin creator Satoshi Nakamoto, although those addresses have become the main focus of the debate because they are estimated to hold about 1 million to 1.1 million BTC.
Zhao later clarified that he was not proposing that Binance or any individual should personally freeze Satoshi-linked coins. He framed the idea as a question for Bitcoin users, miners, and developers to decide collectively if quantum computing becomes capable of deriving private keys from exposed public keys.
Quantum Computing Raises Questions About Dormant Bitcoin
Bitcoin ownership depends on cryptographic signatures that prove control of private keys. A sufficiently capable quantum computer could theoretically calculate a private key from a visible public key, allowing an attacker to spend coins without authorization.
Recent Google Quantum AI research renewed discussion about the resources required for such an attack. Researchers estimated that breaking the cryptography protecting digital signatures may require fewer than 500,000 qubits, below several previous projections, although commercially available machines remain far from that capability.
The risk is concentrated in addresses whose public keys have already appeared on-chain. Estimates cited in the debate suggest that more than one-third of Bitcoin had exposed a public key by March, while other assessments place about 6.9 million BTC in potentially vulnerable address types.
Source: Arkham
Satoshi-linked wallets receive particular attention because the Patoshi pattern identified by researcher Sergio Demian Lerner suggests Bitcoin’s creator mined about 1.1 million BTC during 2009 and 2010. At a Bitcoin price near $59,444, those holdings would be worth close to $65 billion.
CZ Proposes a Limited Migration Period
Zhao said a future Bitcoin upgrade could introduce quantum-resistant addresses and provide users with advance notice to transfer their holdings. Under his proposal, coins left in older vulnerable addresses after the migration period would become unspendable under the new protocol rules.
The aim would be to prevent a quantum attacker from taking control of dormant coins after cracking their private keys. Zhao acknowledged that no option would satisfy every participant because freezing coins would interfere with Bitcoin’s established principle that valid private-key signatures determine ownership.
Identifying Satoshi’s wallets separately from those belonging to other early miners would also be difficult. For that reason, any policy would probably need to apply to a technical category of vulnerable addresses rather than a list associated with one person.
Zhao said the final decision could be reached through miner signaling and broader community coordination. He also warned that leaving vulnerable coins accessible could eventually allow the first successful attacker to claim them.
Draft Proposal Offers a Longer Transition
Zhao’s comments are similar to BIP-361, a draft proposal developed by Jameson Lopp and five other researchers. The draft would gradually restrict vulnerable address types after the activation of quantum-resistant alternatives.
Under the proposal, the network would stop accepting payments to vulnerable addresses about three years after activation. Legacy signatures would then become invalid two years later, giving users a longer period to migrate their holdings.
Supporters of this approach argue that freezing exposed coins may be preferable to allowing a quantum attacker to seize them. Critics contend that invalidating previously accepted signatures would amount to confiscation and alter Bitcoin’s property protections.
Governments are also preparing for a transition away from current cryptographic standards. U.S. initiatives have recently called for federal agencies to adopt post-quantum cryptography over the coming years, while public funding is being directed toward quantum computing and security research.
