The fear that quantum computers could one day break Bitcoin’s cryptography has sparked heated debate across the crypto industry.
But according to Alex Thorn, head of research at Galaxy Digital ( GLXY ), the narrative that Bitcoin is unprepared or that investors should avoid exposure because of it is overstated.
The risk itself is not imaginary. A sufficiently advanced quantum computer could, in theory, derive private keys from exposed public keys, enabling an attacker to forge signatures and steal money. But Thorn argues that framing this as an imminent or uniquely Bitcoin-specific crisis misses critical context, both about the technology and about the work already underway to solve it.
“The risk is real, but recognized,” Thorn told CoinDesk in an interview. “And the people who are best positioned to solve it are actively working on it.”
Quantum computing is a fundamentally different approach to computation that uses the principles of quantum mechanics rather than classical physics. Instead of traditional bits that are either 0 or 1, quantum computers use “qubits,” which can exist in multiple states at once, a property known as superposition, which allows them to process many possibilities simultaneously.
Combined with another feature called entanglement, this enables quantum machines to solve certain complex problems far more efficiently than classical computers, especially tasks like factoring large numbers that underpin modern encryption
Analysis by Project Eleven, a security firm focused on quantum risks in digital assets, suggests that around 7 million bitcoin worth about $470 billion at recent prices, could be vulnerable under a definition of “long exposure,” meaning their public keys have already been exposed on-chain. Other estimates vary widely depending on how exposure is defined.
It is important that most bitcoin today is not immediately vulnerable. Funds are only at risk in scenarios where public keys are exposed on-chain, either because users reused addresses, certain custodians use operational shortcuts, or coins sit in older address formats. While some estimates suggest that millions of BTC fall into these categories, they remain secure under current, publicly known quantum capacities.
That distinction is central to Galaxy’s argument. The conversation has been polarized between those who dismiss quantum computers as decades away and those who warn of imminent danger. Thorn’s view lands in between. The likelihood of a future threat is meaningful enough to warrant action, but not so urgent that it exceeds Bitcoin’s ability to respond.
And that response is already underway.
A growing amount of technical work is focused on making Bitcoin “quantum-resistant” over time. One of the most prominent efforts involves introducing new address types that rely on post-quantum cryptography. These will allow users to migrate funds away from potentially vulnerable formats, significantly reducing long-term exposure.
“There’s a lot more work being done than people realize,” Thorn said. “Developers are actively building ways to upgrade the system.”
Other proposals address edge cases, such as dormant coins with permanently visible public keys. One idea, sometimes referred to as an “hourglass” approach, would gradually limit how such coins can be used, reducing systemic risk without outright confiscation or disruption.
More broadly, developers are exploring incremental upgrade paths that would allow Bitcoin to adapt even under more extreme scenarios, such as a world where quantum systems can quickly break existing cryptographic schemes. That could include changes to how transactions expose public keys in the first place, completely limiting attack surfaces.
While these efforts are complex, both technically and from a management standpoint, Thorn emphasizes that Bitcoin’s open development model is a strength, not a weakness. The ecosystem has the time, talent and strong incentives to solve the problem well before it becomes critical.
Crucially, the number of actors capable of triggering a so-called “Q-day” when quantum computers can break modern cryptography is still extremely limited. Even optimistic projections suggest that only a small group of highly specialized researchers could achieve such a breakthrough in the foreseeable future.
Against this background, Thorn views the growing wave of quantum-related fear, uncertainty and doubt as disproportionate.
“Quantum computing is a powerful, potentially disruptive technology, but that doesn’t mean every risk is immediate or unforeseeable,” he said.
For investors, the takeaway is straightforward. Quantum risk should be monitored but not used as a blanket justification for avoiding bitcoin exposure. The network has a track record of evolving in response to credible threats, and the foundation for quantum resilience is already being laid.
“It’s not certain that quantum is an existential problem for bitcoin, but the chance of it warrants concern,” Thorn said. “But what is clear today is that Bitcoin developers are not ignoring it. Instead, many are actively working on it,” he added.
Read more: Cathie Wood’s Ark Invest says quantum computing is a long-term risk for bitcoin, not an immediate threat
