Quantum Computing Threat Raises Doubts Over Bitcoin Security

For years, Bitcoin has enjoyed a reputation as the digital world’s answer to gold—a secure, decentralized store of value, protected not by vaults or governments, but by the unbreakable logic of mathematics. Yet, as the world inches closer to a new era of computing, that very foundation is being called into question. On January 17, 2026, Chris Wood, the global head of equity strategy at Jefferies, issued a warning that sent ripples through the financial and technological communities: the rise of Cryptographically Relevant Quantum Computers (CRQCs) could threaten the cryptographic backbone that keeps Bitcoin safe.

Wood’s note, highlighted in his widely read newsletter Greed and Fear, didn’t sound the alarm for an immediate crisis. Instead, he framed the issue as an existential vulnerability, one that’s been quietly debated in cryptography circles for years but is now making its way to the heart of mainstream finance. According to Economic Times, Wood explained, “There is an ongoing discussion about whether to ‘burn’ the quantum-vulnerable coins or to do nothing and risk having those vulnerable coins being ‘stolen’ by entities with so-called CRQCs.”

To understand the gravity of this debate, it helps to revisit how Bitcoin’s security works. At its core, Bitcoin relies on asymmetric cryptography. Anyone can receive Bitcoin using a public key, but only the holder of the corresponding private key can spend it. The mathematical relationship between the two is intentionally one-way: while it’s easy to generate a public key from a private key, reversing the process is, with today’s classical computers, practically impossible. As Wood noted, “even the most powerful supercomputers would take trillions of years to derive a private key from a public one using brute force.” This lopsided equation is what makes Bitcoin trustworthy as a digital asset—ownership is protected not by trust in a central authority, but by the sheer computational effort required to break the code.

But what if that effort were suddenly trivial? Enter quantum computing—a technology that, while still in its infancy, promises to upend the world of cryptography. CRQCs, if realized, could perform certain calculations exponentially faster than any classical computer. In the context of Bitcoin, this means that the time required to derive a private key from a public key could shrink from trillions of years to mere hours or days. As Wood starkly put it, “this asymmetry collapses with the arrival of CRQCs, reducing the time to derive a private key from a public key to mere hours or days.”

Such a development would not just be a technical hiccup; it could undermine the very premise of Bitcoin as a secure, decentralized store of value. According to Bloomberg, Wood argued, “Any credible threat to that quantitative tightening is potentially existential. If ownership can no longer be guaranteed with confidence, the concept of Bitcoin as a secure alternative to gold is weakened, regardless of how distant the threat may appear.”

One particularly vulnerable group of coins are those whose public keys have already been exposed—often older bitcoins that have been moved or spent in the past. These coins, if quantum computing advances as feared, could be at risk of theft. This possibility has fueled a contentious debate within the Bitcoin community: should these “quantum-vulnerable” coins be preemptively rendered unusable, or “burned,” to protect the system’s integrity? Or should the community wait, risking that these coins might one day be stolen by an entity wielding a quantum computer?

Proponents of preemptive action argue that burning the vulnerable coins would preserve Bitcoin’s reputation as a system designed to protect property rights. As Wood put it, “Those arguing for pre-emptive action that burning the vulnerable coins will preserve Bitcoin’s integrity as a system designed to protect property rights.” On the other hand, some see this as an unnecessary and drastic step, preferring to wait until the risk becomes more tangible.

This isn’t the first time the Bitcoin community has faced the need for change. According to Economic Times, “It is also the case that it can be legitimately argued that so-called forks in Bitcoin have happened where rules have been changed following a debate within the community.” Indeed, the network has experienced forks and rule changes before, often after intense and sometimes bitter internal debate. These precedents suggest that, if a consensus emerges, the community could adapt to the quantum threat as well.

Wood’s warning wasn’t just theoretical. He took practical action, removing Bitcoin from his model portfolio and replacing it with gold and gold-mining stocks. As reported by Bloomberg, this move “reflected not a judgment on Bitcoin’s recent performance but a reassessment of long-term risk.” For Wood, the shift wasn’t about short-term price swings; it was about whether Bitcoin could continue to serve its intended role as a digital alternative to gold in a world where quantum computing might soon make today’s cryptography obsolete.

Bitcoin’s allure as “digital gold” rests on its supply schedule—a pre-programmed, steadily tightening issuance that will end with the final coin mined around 2140. This built-in scarcity is often cited as Bitcoin’s defining feature, the reason it’s seen as a hedge against inflation and a store of value. But as Wood pointed out, if the underlying security model is breached, that scarcity loses much of its meaning. Ownership, after all, is only as secure as the mathematics that protect it.

It’s worth noting that the quantum threat isn’t unique to Bitcoin. Many digital systems, including those that underpin banking, online security, and even government communications, rely on similar cryptographic assumptions. The difference is that Bitcoin, by design, is open and unmediated—there’s no central authority to patch things up if the math fails. This makes the stakes particularly high for the world’s most prominent cryptocurrency.

For now, the arrival of CRQCs remains a matter of speculation. Quantum computing is advancing rapidly, but practical, scalable machines capable of breaking Bitcoin’s cryptography are not yet a reality. Still, as Wood’s note makes clear, the time to debate and prepare is now—not after the first quantum-powered theft has occurred.

In the end, the question facing Bitcoin’s community isn’t just technical. It’s philosophical: can a system designed to be immutable and trustless adapt to a future where its core assumptions are upended? Or will the digital gold standard be forced to yield to the relentless march of technological progress? As the debate rages, one thing is certain: the future of Bitcoin—and perhaps the future of digital money itself—hangs in the balance.