Coinbase Publishes Technical Blueprint for Bitcoin's Post-Quantum Transition

Coinbase urges the community to start planning Bitcoin's quantum upgrade now

Coinbase has published a set of technical priorities for how Bitcoin should transition to quantum-resistant cryptography. The crypto exchange, which holds about 5% of all bitcoin, argues that the move is a complex, multi-year effort that needs to begin well before a cryptographically relevant quantum computer (CRQC) is announced. The document outlines design preferences for new signature schemes, wallet migration strategies, and handling of coins that may never move.

Key technical preferences

• Separate the transaction container from the signature scheme so that cryptographic methods can be added, replaced, or supplemented without redesigning the entire system. Coinbase points to P2MR (BIP-360) and P2TRv2 as constructions that offer this kind of flexibility.
• Use staged protection: active wallets should be able to adopt a quantum-capable or hybrid scheme before any final decision on legacy signatures is made. One suggested approach is a 1-of-2 structure that gives the same funds two spending paths — one using a classical ECDSA or Schnorr key and one using a post-quantum key.
• Pair any stateful signature support with a stateless option. Stateful designs rely on tracking which keys have been used, and mismanaging that state can lead to signature forgery.
• Ensure at least one viable post-quantum option has strong multiparty computation (MPC) compatibility, which lets multiple parties jointly control a key without any single party holding it alone — an important layer of defense for large custodians.
• Begin discussions about abandoned or inaccessible coins in parallel with technical work on post-quantum signatures, rather than waiting.

What Coinbase said about the timeline

"We believe it is important to begin preparing well ahead of any CRQC announcement," Coinbase wrote. "Bitcoin consensus changes and ecosystem migrations can take years, so it is important that we begin this work now." The exchange confirmed it is already preparing its own systems for a post-quantum future.

What is confirmed

• Coinbase has published a technical priorities document for Bitcoin's post-quantum transition.
• The exchange holds approximately 5% of the total bitcoin supply.
• Coinbase is currently working on its own systems to prepare for a post-quantum future.
• P2MR (BIP-360), P2TRv2, 1-of-2 hybrid constructions, and MPC-compatible schemes are all mentioned as specific design options.

What remains unresolved

The document does not set a deadline or specify when any upgrade would go live. Coinbase also acknowledges that the question of abandoned or inaccessible coins is difficult and that debate on that topic can continue alongside the technical work. No consensus among the broader Bitcoin community on these priorities has been reached yet based on the supplied material.

Why this matters for bitcoin holders

If a sufficiently powerful quantum computer were built, it could in principle break the cryptographic signatures that protect bitcoin today, potentially putting all coins signed with current key types at risk. Coinbase's document lays out what it sees as practical design goals so that the network can resist that kind of threat — protecting both coins already spent and newly created ones, staying within limited block space, keeping full nodes independently verifiable, working with institutional custody systems, and supporting everyday wallets.

"Coinbase believes that Bitcoin will continue to be the most trusted cryptocurrency in a post-quantum world," the exchange stated, adding that it wants to contribute to community efforts for "careful, sustained progress."

Source

• The Block

Read also: Researchers Build First Working Post-Quantum Defense for Bitcoin's Lightning Network