Bitcoin's post-quantum security is moving from theoretical concern to practical priority. Coinbase, which custodies roughly 5% of all Bitcoin, has published a detailed position paper urging the Bitcoin ecosystem to begin migration preparations immediately, rather than waiting until a quantum threat materializes.
The exchange argues that the timeline for consensus changes, wallet upgrades, and ecosystem coordination could span years. Delaying action until a confirmed threat emerges, Coinbase warns, would not allow sufficient time for an orderly transition.
Seven Priorities for Post-Quantum Readiness
Coinbase's proposal outlines seven technical priorities for the community. At its core is a flexible output design that separates the output container from the signature scheme, allowing new post-quantum algorithms to be introduced without a full protocol redesign. The exchange points to BIP-360 (P2MR) and P2TRv2 as early constructions worth developing further.
For active wallets, Coinbase proposes a staged, hybrid approach using constructions like 1-of-2 keys that permit spending through either classical ECDSA or post-quantum keys. This would enable gradual migration before final policy decisions on legacy signatures are made.
The proposal also addresses institutional custody concerns, emphasizing that at least one post-quantum scheme must be compatible with multi-party computation (MPC). Coinbase previously identified this compatibility gap in September when revealing it was engineering post-quantum custody for approximately $250 billion in institutional assets.
Candidate signature schemes named in the proposal include ML-DSA, SLH-DSA, FN-DSA, and SHRINCS. Coinbase calls for a Bitcoin-specific evaluation process, noting that standard TLS and PKI rankings do not account for Bitcoin's block-space constraints and long-lived, globally verified signatures.
Growing Industry Focus on Quantum Risk
Coinbase's position paper arrives as institutional pressure on quantum readiness intensifies across the cryptocurrency sector. In July, Coinbase co-founded the Bitcoin Security Consortium with BlackRock, Strategy, and ARK Invest, pledging $15 million over three years for open-source quantum security research.
Regulatory bodies have also amplified the urgency. The EU flagged post-quantum migration as a systemic risk for crypto in late September, while Europol identified wallets as the primary vulnerability and urged exchanges and developers to begin work immediately.
Other industry participants are taking action. BitGo launched a Quantum Resistance Score and wallet protection toolkit, while Zcash developers have moved to target quantum-resistant payments by January 2027.
For institutional Bitcoin holders, Coinbase's message is direct: post-quantum preparation is not optional infrastructure work but rather a multi-year governance and engineering challenge that must begin now.
