Quantum computers still can’t break Bitcoin, but several major blockchains are preparing for a future in which they could.
Last week, when Solana tested quantum-resistant transactions, Aptos proposed post-quantum signature support. Meanwhile, parts of the Bitcoin community renewed calls to accelerate work on a quantum-safe upgrade.
These developments point to growing concern in crypto. Investors argue that the dismissal of quantum risk by influential voices is hurting the price of Bitcoin (BTC), which has fallen 24% in the past three months.
While altcoins are experimenting with post-quantum security through blockchain opt-in upgrades and test networks, Bitcoin is divided on how it should publicly and immediately address quantum risks.
How are blockchains preparing without raising alarms?
Ethereum has been clear about why quantum computing is now being treated as an engineering problem rather than a distant hypothetical.
Ethereum co-founder Vitalik Buterin has argued that when the costs of failure are high and the time required to migrate global systems is measured in years, prompt preparation is needed even for a low-probability outcome.
Citing forecast models, they say there is about a 20% chance that quantum computers capable of breaking today’s public-key cryptography could emerge before 2030, with an average estimate closer to 2040. Buterin reportedly said that no machines exist today that can break Bitcoin or Ethereum, but waiting for certainty is risky in itself, as it could take years for the global network to shift to post-quantum schemes.
This framing is beginning to be echoed in other major blockchains, especially those that can experiment without reopening the fundamental debate.
Aptos has proposed adding post-quantum signature support at the account level through an opt-in upgrade that would leave existing accounts untouched. The proposal relies on a hash-based signature scheme and is pitched as future-proofing rather than a response to an imminent threat. Users can adopt the new plan if they wish, without being forced to commit to a network-wide migration.
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Solana has taken a similar approach through testing rather than deployment. In partnership with post-quantum security firm Project Eleven, the network recently ran a dedicated testnet using quantum-resistant signatures to assess whether such schemes could be integrated without reducing performance or compatibility.
Bitcoin’s quantum debate is really about trust
Bitcoin relies on elliptic curve cryptography to verify ownership. Control over funds is proven through a private key, while only the corresponding public key is revealed on chain.
In theory, a sufficiently powerful quantum computer running Shor’s algorithm could work backwards from the public key to recover the private key, allowing the attacker to spend the funds without any obvious signs of theft. From the network’s perspective, those coins will move as if their owner decided to make the transaction.
Even proponents of post-quantum upgrades generally acknowledge that cryptographically relevant machines are still years away. But controversy remains in the Bitcoin community over how Bitcoin should respond to a risk that is far-reaching, uncertain and difficult to detect once it emerges.
On one hand, developers and longtime Bitcoin cryptographers argue that making quantum computing an immediate concern does more harm than good.
Blockstream CEO Adam Back has repeatedly dismissed near-term quantum fears, insisting that practical quantum attacks remain decades away. He claimed that increasing quantum risks spreads panic and encourages markets to price in a threat that does not yet exist.
On the other hand, investors and researchers argue that even a low-probability outcome matters for an asset whose value depends on long-term confidence. Nick Carter, partner at Castle Island Ventures, called the blanket dismissal of quantum risks by influential developers as bearish.
Craig Warmke of the Bitcoin Policy Institute similarly warned that perceived complacency is leading some capital to diversify away from Bitcoin, even if the underlying technical fears are accurately expressed.
This tension explains why Bitcoin reform proposals like Proposal 360, which would introduce a quantum-resistant signature option, provoke outside reactions despite their preliminary and tentative status.
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Proponents see the early work as a way to reduce uncertainty and signal preparations. Critics see this very discussion as legitimizing speculative risk and inviting confusion about Bitcoin’s resilience.
Why does quantum uncertainty matter differently for Bitcoin?
Quantum computers cannot break Bitcoin or any major blockchain today. What is already happening is that the uncertainty around quantum risk is influencing how different networks choose to communicate and how investors interpret those choices.
Outside of Bitcoin, post-quantum work has been designed as infrastructure. Opt-in upgrades and testing allow the network blockchain to signal preparedness without forcing users or markets to reevaluate current security assumptions. This approach limits the reputational costs of initial preparation while maintaining flexibility if deadlines change.
Bitcoin operates under various constraints. Because its value is closely tied to long-term assurances about security and durability, discussions about future-proofing its cryptography attract immediate scrutiny. What might otherwise be perceived as routine contingency planning can more easily be read as a commentary on the fundamentals of Bitcoin.
Influential voices related to Bitcoin worry that emphasizing distant risks invites misunderstanding and panic. Investors worry that downplaying those risks signals a lack of contingency planning. Both sides are reacting to how confidence takes shape in the absence of a clear timeline.
The quantum debate suggests that for Bitcoin, managing how long-term risks are discussed may be as important as managing the risks themselves.
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