Quantum computers still can’t crack Bitcoin, but several major blockchains are preparing for a future where they can.
Last week, Aptos proposed post-quantum signature support as Solana tested quantum-resistant transactions. Meanwhile, some in the Bitcoin community have renewed calls to accelerate work on updates to ensure quantum security.
These developments indicate growing concern around cryptocurrencies. Investors argue that the rejection of quantum risk by influential voices is weighing on the price of Bitcoin (BTC), which has fallen 24% over the past three months.
While altcoin blockchains experiment with post-quantum security through opt-in enhancements and testnets, Bitcoin remains divided over how publicly and urgently it should address quantum threats.
How blockchains prepare without sounding the alarm
Ethereum has made it clear why quantum computing is now treated as an engineering problem rather than a distant hypothesis.
Ethereum co-founder Vitalik Buterin argued that even a low-probability outcome requires early preparation when the cost of failure is high and the time required to migrate global systems is measured in years.
Citing predictive models, he said there is about a 20% chance that quantum computers capable of breaking today’s public key cryptography will emerge before 2030, with the median estimate being closer to 2040. Buterin reportedly said there are currently no machines that can crack Bitcoin or Ethereum, but waiting for certainty is itself risky because the global network could take years to migrate to post-quantum schemes.
This approach has begun to echo across other major blockchains, especially those that can experiment without reopening fundamental debates.
You did it proposed adding post-quantum signature support at the account level via an optional update that would leave existing accounts untouched. The proposal is based on a hash-based signature scheme and is positioned as a future-proofing rather than a response to an immediate threat. Users can adopt the novel scheme if they want without forcing a network-wide migration.
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Solana took a similar approach by testing rather than implementing. IN cooperation In collaboration with post-quantum security company Project Eleven, the network recently launched a dedicated testnet using quantum-resistant signatures to assess whether such schemes can be integrated without compromising performance and compatibility.
The quantum debate over Bitcoin is really about trust
Bitcoin relies on elliptic curve cryptography to verify ownership. Control of the funds is confirmed using the private key, while only the corresponding public key is revealed on the chain.
Theoretically, a sufficiently powerful quantum computer running Shor’s algorithm could work backwards, starting with the public key, to recover the private key, allowing an attacker to spend the funds without triggering any obvious signs of theft. From the network’s perspective, these coins would simply move as if their owner decided to transact.
Even proponents of post-quantum improvements generally admit that cryptographically significant machines are still many years away. However, the disagreement within the Bitcoin community is how Bitcoin should respond to risks that are distant, uncertain, and challenging to detect once they materialize.
On the one hand, Bitcoin developers and longtime cryptographers argue that treating quantum computing as an urgent issue does more harm than good.
Blockstream CEO Adam Back has said this many times released short-term quantum concerns, emphasizing that practical quantum attacks will not be realized for several decades. He argued that increasing quantum risk fuels 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 assets whose value depends on long-term certainty. Castle Island Ventures partner Nic Carter described the complete rejection of quantum risk by influential developers as bearish.
Craig Warmke of the Bitcoin Policy Institute feels similarly warned that perceived complacency is driving some capital to diversify away from Bitcoin, regardless of whether the underlying technical concerns are precisely articulated.
This tension explains why suggestions such as Bitcoin Improvement Proposal 360, which would introduce quantum-resistant signature options, are generating huge reactions despite their early and preliminary status.
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Supporters see early work as a way to reduce uncertainty and signal readiness. Critics see the same discussion as legitimizing the speculative threat and creating confusion about Bitcoin’s resilience.
Why quantum uncertainty matters differently for Bitcoin
Today’s quantum computers cannot break Bitcoin or any major blockchain. What is already happening is that uncertainty around quantum risk is impacting how different networks choose to communicate and how investors interpret those choices.
Outside of Bitcoin, post-quantum work is referred to as infrastructure. Opt-in improvements and testnets allow blockchains to signal readiness without forcing users or markets to re-evaluate current security assumptions. This approach reduces the reputational costs of early preparation while maintaining flexibility when the schedule changes.
Bitcoin operates under various restrictions. Because its value is closely tied to long-term security and durability guarantees, discussions about future-proofing its cryptography tend to attract immediate attention. What might otherwise be taken as routine contingency planning can more easily be read as commentary on Bitcoin’s fundamentals.
Influential voices in Bitcoin fear that emphasizing distant threats is leading to misunderstandings and panic. Investors fear that minimizing this risk signals a lack of contingency planning. Both sides respond to how trust develops in the absence of a clear time frame.
The quantum debate suggests that in Bitcoin’s case, managing how long-term risk is discussed may be as crucial as managing the risk itself.
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