- Developers have proposed a formal Bitcoin Improvement Proposal (BIP) to address future quantum computing threats
- The plan outlines a migration strategy to secure funds that could be vulnerable to quantum attacks
- Community discussions around cryptographic agility and user experience have already begun
A new proposal has been tabled to prepare Bitcoin for the looming challenge of quantum computing. Drafted by Bitcoin advocate Jameson Lopp and others, the post-quantum migration plan suggests a formal method for users to safely move their funds to addresses secured by quantum-resistant cryptography before it’s too late. The initiative signals a proactive shift in the Bitcoin ecosystem, focusing not just on security but on practical coordination and user protection in the face of emerging threats.
Preparing for a Quantum Threat
Although today’s quantum computers are far from breaking Bitcoin’s cryptography, experts agree it’s wise to prepare early. The proposal outlines a multi-step process allowing users to voluntarily migrate their coins away from legacy addresses—specifically those that have already exposed their public keys—into new, quantum-safe addresses.
The ethos of the plan takes away from the notion that changes will be forced upon the Bitcoin-holding public in favour of a “private incentive to upgrade”:
This is not an offensive attack, rather, it is defensive: our thesis is that the Bitcoin ecosystem wishes to defend itself and its interests against those who would prefer to do nothing and allow a malicious actor to destroy both value and trust.
This includes coins already spent once from a Pay-to-PubKey (P2PK) address or Pay-to-PubKey-Hash (P2PKH) address, where the public key is revealed upon spending.
How It Would Work
The migration would be supported via a standardized message protocol that communicates an intention to move funds, paired with a cryptographic signature to verify ownership. The process would rely on a soft fork to introduce a new address type called Pay-to-Post-Quantum-Public-Key-Hash (P2PQPKH), which would avoid double-spending during migration.
A notable element is the proposed creation of a “Final Spend Height,” a future block height after which only P2PQPKH spends would be valid for the migrated coins. “The migration window should be open for multiple years,” the proposal adds, ensuring users have ample time to adjust.
Community Response and Wider Context
While the threat from quantum computing isn’t immediate, the community has increasingly acknowledged it as a real, long-term risk. Lopp’s proposal is an attempt to get ahead of that risk without rushing the network into disruptive changes. By making the plan opt-in and gradual, it strikes a balance between urgency and decentralization.
It also raises broader questions about cryptographic agility in Bitcoin: how quickly the network can pivot when threats emerge. Last month, Deloitte reported that the biggest challenge facing those wishing to enact such protection measures was coordination rather than anything technical, with many equating corralling Bitcoin miners to do anything like herding cats. As Lopp himself asked at the time, “Can Bitcoin come together and find consensus on how to mitigate this threat before it really becomes an existential crisis?”
