An analysis said it is unlikely that a “Q-day” in which quantum computing suddenly collapses Bitcoin security will occur. It said technological progress is likely to be gradual, giving the Bitcoin network enough time to prepare and adapt.

On March 12, blockchain media outlet BeInCrypto reported that a joint white paper released by investment firm Ark Invest and Bitcoin financial services company Unchained analysed how quantum computing could affect Bitcoin security and presented a five-stage framework for assessing it.

The paper said current quantum computing is assessed at level 0. At this stage, quantum computers exist but their commercial use and performance are limited. Current systems remain in the “NISQ era,” operating at about 100 logical qubits, leaving a large gap versus the performance needed to break elliptic curve cryptography (ECC), Bitcoin’s core security technology.

The researchers estimated that decrypting Bitcoin would require at least 2,330 logical qubits and tens of millions to billions of quantum gate operations. That is far above current technology.

At level 1, quantum computers begin to be used commercially in specific industries such as chemistry and materials science. At level 2, relatively weak cryptosystems or older cryptographic technologies are likely to become early targets.

The stage at which Bitcoin faces a real threat is level 3. At this level, quantum computers could theoretically attack the algorithm that protects Bitcoin private keys. The analysis said an actual attack would still require a significant amount of time.

It said some Bitcoin addresses (P2PK) created before 2011 could be relatively vulnerable to quantum attacks, but more recently used address structures have evolved in a direction that strengthens quantum resistance.

The most serious situation is level 4. At this level, a quantum computer could decrypt private keys faster than Bitcoin’s 10-minute block generation time. If there is no network-level response by then, Bitcoin could face a serious threat as a monetary system.

The report stressed that technical alternatives are already being discussed to prepare for such a situation. It said address structures based on post-quantum cryptography (PQC) have been proposed, and participants in the Bitcoin ecosystem have strong incentives to adopt them if needed.

The report also presented three scenarios in which the quantum computing threat could become real. The first is a pessimistic scenario in which quantum computers advance rapidly due to an unexpected technological breakthrough. The second is an optimistic scenario in which progress slows due to technical barriers. Finally, it said the most realistic scenario is that quantum technology reaches a stage that poses a practical threat to Bitcoin within 10 to 20 years.

In conclusion, the report assessed quantum computing as a long-term risk factor but not an immediate threat to Bitcoin. The researchers stressed that the Bitcoin community has enough time to prepare quantum-resistant upgrades while continuously tracking technological advances.