Coinbase urges Bitcoin to begin a quantum defense plan now

Coinbase said Bitcoin should start preparing for quantum computers now. The exchange, which holds about 5% of all bitcoin, published a technical paper on 13 October 2026 warning that a shift to quantum-safe addresses could take years and must begin early.

Those claims build on a 50-page position paper that Coinbase's Independent Advisory Board on Quantum Computing and Blockchain released in April 2026. That board is an outside panel of cryptographers, among them Stanford's Dan Boneh and the Ethereum Foundation's Justin Drake. CoinDesk and crypto.news both covered the new post on 14 October.

What Coinbase is asking for

Coinbase did not pick one solution. It set out a list of principles for developers to follow. The main one is simple. Build Bitcoin's transaction format so it can take new signature types later, without tearing up the whole system. The paper points to two draft proposals, BIP-360 and P2TRv2, as examples of that flexible design.

BIP-360 is a real proposal, filed by developers Hunter Beast, Ethan Heilman and Isabel Foxen Duke. It is still marked a draft. It would add a new address type called Pay-to-Merkle-Root, with addresses that start with bc1z, built to resist a quantum computer that has had long exposure to a public key.

A second draft, BIP-361, takes the harder step. Labeled Post Quantum Migration and Legacy Signature Sunset, it would gradually switch off the old signature rules that leave keys exposed. The candidates for the new signatures carry names only a cryptographer could love, among them ML-DSA and SLH-DSA, both already blessed by US standards bodies. Coinbase backed no single scheme. It asked that whatever wins work with the multi-party setups large custodians use to guard keys.

Coinbase also supports a staged path for everyday holders. One idea is a hybrid wallet. It would let an owner spend coins with either a normal key or a new quantum-safe key, a setup the paper calls one-of-two. Active holders could move to protected addresses first, long before the network forces the issue.

How much bitcoin sits exposed

Here is the part that makes this more than theory. A Bitcoin address stays safe until coins are spent from it, because only then does its public key go on the chain. A future quantum computer could read that exposed key and work backward to the private one. Coins that have already moved, or that reuse an address, carry the risk now.

Coinbase's advisory board estimates about 6.9 million BTC sit in wallets with public keys already exposed on the chain. That is roughly $570 billion at bitcoin's price near $82,000 around 20:00 UTC on 14 October 2026, according to CoinGecko. Nobody can say how many of those wallets still have an owner.

This is not the board's first warning. Its April paper drew a panel that reaches well past Coinbase, from Stanford to the Ethereum Foundation to UC Santa Barbara. A follow-up in June counted a narrower danger, about 1.7 million BTC spread across some 20,000 keys. Even the experts disagree on the size of the hole.

The problem of lost and dormant coins

Some of those exposed coins belong to people who are long gone. Others sit in wallets whose owners lost the keys years ago. A large share dates to Bitcoin's first years and has never moved, including coins linked to its pseudonymous creator, Satoshi Nakamoto. What happens to them splits the room.

Three blunt options sit on the table. Let the old coins be swept by whoever upgrades the rules. Freeze them so no quantum thief can touch them. Or burn them for good. Coinbase took no side. It argued only that the debate should run on a separate track, so it does not hold up protection for wallets people still use. The company warned that an attacker could build a quantum machine in secret and drain dormant wallets before the public ever hears of it.

How close is the quantum threat?

No quantum computer can break Bitcoin today. The machines that exist are far too small and too error-prone. The worry is timing. Google researchers have said a cryptographically relevant quantum computer, one strong enough to matter, could arrive by 2029. Others put it further out. A threat with no fixed date.

That uncertainty cuts both ways. Start too late and millions of coins are at risk. Start too early and Bitcoin spends years on soft forks for a danger that may still be a decade away. Changes to the protocol move slowly by design. The recent Bitcoin Core 32.0 release took months of review for far smaller work. Coinbase's own holdings give it a reason to press hard, and it is not alone in moving early. Starknet has floated leaving Ethereum to rebuild as a quantum-resistant chain.

What to watch

The next step is whether these proposals win real support among Bitcoin's developers. BIP-360 and the others are drafts, not code the network has agreed to run. A change this size would need a soft fork and broad agreement, a process that has taken the community years before. Watch for a working group to form around post-quantum signatures, and for wallets to start offering the hybrid option Coinbase described. Until then, nothing about how bitcoin works has changed for holders.