Coinbase Warns Bitcoin Quantum Upgrade Could Take Years, Here Is Its Plan

TLDR

• Coinbase told Bitcoin developers to start preparing for quantum computing threats in an October 13 technical paper.
• The company said upgrading Bitcoin’s security could take several years.
• Coinbase backed flexible designs such as BIP-360 and P2TRv2 for adding new signature systems.
• It proposed hybrid wallets that support both current and post-quantum keys.
• Coinbase said debates over lost and dormant coins should be kept separate from the technical work.

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Coinbase has urged Bitcoin developers to start preparing for quantum computing threats. The company shared its views in a technical paper on October 13.

Coinbase, Which Holds About 5% of Existing BTC in Custody, Outlines Bitcoin Post-Quantum Security Recommendations

Coinbase, which holds approximately 5% of all existing BTC in custody, outlined technical considerations for Bitcoin’s transition to post-quantum security. The… pic.twitter.com/9D9aUAXTa2

— Wu Blockchain (@WuBlockchain) October 13, 2026

Coinbase said upgrading Bitcoin’s security could take several years. It holds about 5% of all existing Bitcoin in custody. The paper was published on Tuesday.

The paper does not claim a quantum computer can break Bitcoin today. Coinbase described the threat as a future possibility that needs early planning.

How Bitcoin could be exposed

Bitcoin uses elliptic-curve cryptography, including ECDSA and Schnorr signatures, to approve transactions. A powerful quantum computer could theoretically work out private keys from exposed public keys.

Coinbase said a move to quantum-resistant security involves more than a new signature method. Developers must weigh fees, network capacity, wallet support and independent verification by nodes.

The company supports BIP-360 and P2TRv2 as flexible designs. These would let developers add or swap signature systems without rebuilding transactions each time.

BIP-360 is a draft proposal that removes a Taproot spending option that exposes a public key. It does not add a post-quantum signature on its own.

Coinbase also named signature options such as ML-DSA, SLH-DSA and FN-DSA. It said developers should test signature size, speed, fees and hardware support.

In March, BTQ Technologies reported testing experimental BIP-360 transactions on a test network. That work did not activate the proposal on Bitcoin’s main network.

Hybrid wallets and lost coins

Coinbase proposed hybrid wallets with two ways to spend. Users could sign with a current key or with a separate post-quantum key.

The company called this a 1-of-2 design. It would let users upgrade protection before rules for older signatures are final.

For large custodians, Coinbase said new systems should work with multiparty computation. It also asked for a stateless signing option, since reused signing state can lead to forgery.

Coinbase said questions about dormant coins and lost keys should be debated separately. Those talks should not slow work on protecting active wallets.

The paper discussed possible recovery methods using wallet seed information and cryptographic proofs. Coinbase cautioned that any method must stay secure against an attacker who holds only an exposed public key.

A separate proposal, BIP-361, would gradually restrict older signatures. It remains a draft and has not been activated.

The paper called for more testing of transaction verification, hardware wallets, fees and block propagation. Coinbase asked for a repeatable process to compare signature systems under realistic network conditions.

Coinbase has begun preparing its own custody systems. It has joined talks with researchers and the Bitcoin Security Consortium.

The October 13 paper set no migration deadline and backed no final algorithm. Coinbase said its next steps will continue through talks with researchers, developers and open-source contributors.