A new research report by Ark Invest and bitcoin-focused financial services firm Unchained has concluded that while quantum computing poses a potential long-term risk to Bitcoin's security, it does not represent an immediate threat. The study emphasizes that technological progress will be gradual, giving developers and investors ample time to implement post-quantum security upgrades.
Current State of Quantum Computing: Far from Threatening Bitcoin
The research indicates that today's quantum systems are still in the “Noisy Intermediate-Scale Quantum” (NISQ) era, typically operating with fewer than 100 logical qubits and limited computational depth. Breaking Bitcoin's elliptic curve digital signature algorithm (ECDSA) would require at least 2,330 logical qubits and millions to billions of quantum operations — far beyond current capabilities.
Instead of a sudden “Q-day” where Bitcoin security collapses, researchers argue that quantum progress will likely unfold through a series of gradual technological milestones. These stages range from early scientific applications, such as materials simulation and chemistry, to the eventual ability to attack weak cryptographic systems. Only in later stages could quantum computers begin to threaten Bitcoin's ECDSA, which secures private keys and transactions.
Even then, attacks would likely be slow and costly. The report estimates that electricity costs alone could reach around $100,000 to break a single Bitcoin key in early quantum attack scenarios.
Roughly 35% of Bitcoin Theoretically at Risk, but Majority Safe
Researchers estimate that approximately 35% of the total Bitcoin supply could theoretically be exposed to future quantum risks. This includes about 1.7 million BTC stored in older address types believed to be lost, and roughly 5.2 million BTC in reusable addresses that could be migrated to safer formats.
However, the majority of bitcoin remains stored in quantum-resistant address formats, and developers already have potential solutions in motion. Exchanges like Coinbase have established quantum advisory boards, while developers are discussing proposals such as Bitcoin Improvement Proposal (BIP) 360, which explores new address types designed to withstand quantum attacks.
BIP 360 Introduces P2MR: A Step Toward Quantum Resistance
Bitcoin developers have updated draft BIP 360 to introduce Pay-to-Merkle-Root (P2MR), a proposed output type designed to reduce long-term quantum risk. By binding transaction outputs to Merkle tree roots, P2MR makes it computationally harder for quantum attacks to reverse-engineer public keys, thereby enhancing security.
Security researchers emphasize that before Bitcoin itself becomes vulnerable, the broader internet — including banking systems, government communications, and cloud infrastructure — would face disruption. Post-quantum cryptography (PQC) standards are already being developed and deployed across internet infrastructure. If necessary, Bitcoin could eventually integrate similar cryptographic upgrades through protocol changes.
Conclusion: A Long-Term Challenge, Not an Immediate Crisis
For investors and network participants, the takeaway is clear: quantum computing represents a long-term technological challenge rather than an urgent security crisis. As with most transformative technologies, progress will likely unfold over decades, providing the Bitcoin ecosystem ample time to adapt.