Fears that quantum computing could one day break Bitcoin’s cryptography have sparked heated debate throughout the crypto industry.
But according to Alex Thorn, head of research at Galaxy Digital (GLXY), the narrative that Bitcoin is not ready, or that investors should avoid exposure because of it, is overblown.
The risk itself is not imaginary. In theory, a sufficiently advanced quantum computer could obtain private keys from exposed public keys, allowing an attacker to forge signatures and steal funds. But Thorn argues that framing this as an imminent or exclusively Bitcoin-specific crisis misses critical context, both about the technology and the work already being done to address it.
“The risk is real but recognized,” Thorn told CoinDesk in an interview. “And the people best positioned to solve it are actively working on it.”
Quantum computing is a fundamentally different computing approach that uses the principles of quantum mechanics instead of classical physics. Instead of traditional bits that are 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 allows quantum machines to solve certain complex problems much more efficiently than classical computers, particularly tasks like factoring large numbers that underpin modern encryption.
Analysis by Project Eleven, a security firm focused on the quantum risks of digital assets, suggests that approximately 7 million bitcoins worth around $470 billion at recent prices, they could be vulnerable under a “long exposure” definition, meaning their public keys have already been revealed on-chain. Other estimates vary widely depending on how exposure is defined.
Importantly, most current bitcoins are not immediately vulnerable. Funds are only at risk in scenarios where public keys are exposed on-chain, whether because users reused addresses, certain custodians employ operational shortcuts, or coins are in older address formats. While some estimates suggest that millions of BTC fall into these categories, they remain safe under current and publicly known quantum capabilities.
That distinction is central to Galaxy’s argument. The conversation has polarized between those who dismiss quantum computing as decades away and those who warn of an imminent danger. Thorn’s vision falls in the middle. The probability of a future threat is significant enough to justify action, but not so urgent that it overwhelms Bitcoin’s ability to respond.
And that response is already underway.
A growing body of technical work focuses on making Bitcoin “quantum resistant” over time. One of the most notable efforts involves the introduction of new types of addresses that are based on post-quantum cryptography. This would allow users to migrate funds 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 paths to update the system.”
Other proposals address extreme cases, such as dormant coins with permanently exposed public keys. One idea, sometimes called an “hourglass” approach, would gradually restrict how those coins can be spent, mitigating systemic risk without direct confiscation or disruption.
More broadly, developers are exploring incremental upgrade paths that would allow Bitcoin to adapt to even more extreme scenarios, such as a world where quantum systems can quickly break existing cryptographic schemes. That could include changes to the way transactions reveal public keys in the first place, limiting attack surfaces entirely.
While these efforts are complex, both from a technical and governance perspective, Thorn emphasizes that Bitcoin’s open development model is a strength, not a weakness. The ecosystem has time, talent, and strong incentives to solve the problem long before it becomes critical.
Crucially, the number of actors capable of triggering the so-called “Q day,” when quantum computers can break modern cryptography, remains extremely limited. Even optimistic projections suggest that only a small group of highly specialized researchers could achieve such a breakthrough in the foreseeable future.
In that context, Thorn considers the rising wave of fear, uncertainty and doubt related to quantum disproportionate.
“Quantum computing is a powerful and potentially disruptive technology, but that doesn’t mean all risks are immediate or unmanageable,” he said.
For investors, the conclusion is simple. Quantum risk should be monitored, but not used as a general justification for avoiding exposure to bitcoin. The network has a history 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 possibility that it is warrants concern,” Thorn said. “But what is clear today is that Bitcoin developers are not ignoring it. On the contrary, many are actively working on it,” he added.
Read more: Cathie Wood’s Ark Invest says quantum computing is a long-term risk to bitcoin, not an imminent threat
