A new research paper from Google has intensified debate over whether Bitcoin can adapt in time to withstand advances in quantum computing, pushing developers and investors to confront a risk long treated as theoretical.
Google’s quantum division said this week in a new whitepaper that future machines could break widely used encryption far more efficiently than previously estimated, including the elliptic curve cryptography that underpins Bitcoin wallets.
The research suggests attacks that once appeared decades away may arrive sooner, with some scenarios modeling the ability to crack encryption in minutes under advanced conditions.
The findings do not imply an immediate threat. Today’s quantum computers remain far below the scale required to break modern cryptographic systems. But the paper reduces the estimated resources needed, narrowing the gap between theory and practice and shifting attention toward preparation rather than dismissal.
Google has already set a 2029 target to transition its own systems to post-quantum cryptography, reflecting a broader shift among large technology firms and governments toward defensive planning.
Is Bitcoin under threat?
For Bitcoin, the implications are specific and structural. The network relies on digital signatures that could, in principle, be reversed by a sufficiently powerful quantum computer. Roughly one-third of the total Bitcoin supply sits in addresses where public keys have been exposed, creating a defined set of targets under certain attack models.
Separate analyses cited in the research estimate that about 6.7 million Bitcoin may be exposed to varying degrees under quantum attack scenarios, including coins held in older address formats where public keys remain permanently visible on-chain.
More immediate concerns focus on transaction windows. When a Bitcoin transaction is broadcast, its public key becomes visible before confirmation. Google’s research suggests a theoretical attacker could exploit that gap, solving for the private key within the same time frame it takes for a block to be mined.
That has shifted the conversation among developers from abstract risk to engineering timelines.
Binance founder Changpeng Zhao pushed back on what he described as exaggerated concerns, arguing that most cryptographic systems, including Bitcoin, can migrate to quantum-resistant algorithms without destabilizing the network.
He noted, however, that execution remains a constraint. Coordinating upgrades across a decentralized ecosystem could lead to competing proposals, software fragmentation and potential forks, while users holding assets in self-custody would need to actively migrate funds to new wallet structures.
The Bitcoin ecosystem has begun early-stage work on quantum resistance. A recent proposal, known as BIP 360, introduces new transaction formats designed to remove or reduce exposure to vulnerable cryptographic assumptions. The proposal remains in draft form, but test implementations are already running in experimental environments, allowing developers to evaluate quantum-safe signatures in practice.
Even proponents describe the effort as a starting point rather than a solution. Any upgrade would require broad coordination across a decentralized network, a process that can take years to reach consensus and deploy.
That timeline is central to the emerging debate. Estimates suggest a full migration to quantum-resistant cryptography in Bitcoin could take the better part of a decade, depending on adoption and coordination across wallets, exchanges and infrastructure providers.
The risk, developers say, is not only technological but organizational. Bitcoin has no central authority to mandate upgrades, and changes to its core protocol require agreement among a global set of participants with differing incentives.
Banking, traditional finance at risk as well
The issue also extends beyond cryptocurrency. The same class of cryptography secures banking systems, government communications and large parts of the internet.
In theory, the same cryptographic systems that secure Bitcoin also underpin global banking infrastructure, payment networks and government communications.
Google and cybersecurity agencies warned that attackers may already be collecting encrypted data today in anticipation of future quantum capabilities, a strategy known as “store now, decrypt later.”
Any viable quantum attack would not be isolated to crypto markets, but would extend across financial institutions and critical systems that rely on public-key encryption. Bitcoin is not uniquely vulnerable, but it is uniquely transparent. Its ledger makes exposure visible, and its open-source development model makes its response observable in real time.
Market reaction has remained muted so far, with prices largely unaffected by the latest research.
