A Post Quantum Migration Proposal

This blog post delves into a comprehensive proposal aimed at enhancing Bitcoin's resilience against the potential threat posed by quantum computing. The proposal, built on the foundation of previous discussions and essays, specifically focuses on motivating the Bitcoin community towards adopting and migrating to post-quantum cryptographic standards. It introduces a phased approach that includes implementing a new post-quantum output type (P2QRH) and establishing a timeline for phasing out legacy ECDSA/Schnorr signatures.

The initial phase of the proposal mandates the cessation of sending funds to quantum-vulnerable addresses, promoting the swift adoption of P2QRH address types. This is followed by a period where spending from quantum-vulnerable UTXOs becomes invalid, effectively preventing any transactions using traditional cryptographic methods. An optional third phase considers enabling the recovery of frozen assets through zero-knowledge proofs, contingent on further research and consensus within the community.

The motivation behind this proposal is rooted in the urgent need to safeguard the value stored in the Bitcoin network. Quantum computing presents an unprecedented challenge to Bitcoin's security, with the potential to undermine the cryptographic foundations of the network. Recent advancements in quantum algorithms and the ratification of post-quantum signature schemes by NIST highlight the accelerating pace of quantum progress, underscoring the shrinking safety envelope for classical encryption methods.

A successful quantum attack on Bitcoin could have devastating consequences, not only eroding trust in the network but also causing significant economic damage. Therefore, the proposal argues for a proactive and defensive strategy to mitigate these risks well before such an attack becomes feasible. By setting clear deadlines for the migration to quantum-resistant cryptographic methods, the proposal aims to align stakeholders across the Bitcoin ecosystem, minimizing inertia and ensuring a coordinated response to the quantum threat.

Furthermore, the proposal outlines specific actions required from various stakeholders, including miners, institutional holders, exchanges, custodians, and everyday users. Each group faces unique incentives to upgrade, from protecting investments and hardware to fulfilling fiduciary duties and achieving self-sovereign security. The proposal emphasizes the collective benefit of reducing the attack surface and minimizing potential losses, arguing that the transition to quantum-resistant cryptography is in the best interest of the entire Bitcoin community.

Finally, the proposal addresses backward compatibility, noting that the changes can be implemented as a series of soft forks. This approach allows older nodes to continue operating without modification while strongly encouraging upgrades to fully validate new post-quantum transactions. The phased implementation ensures a gradual transition, providing ample time for stakeholders to migrate to the new standards and maintain the integrity and security of the Bitcoin network against the looming threat of quantum computing.