2029 May Be the Turning Point for the Quantum Computing Threat

In recent weeks, Google Research released a whitepaper stating that in the future, a sufficiently powerful quantum computer could potentially break a significant portion of the cryptography currently securing the Bitcoin network. The authors established a remarkably specific timeframe for this to happen: 2029.

According to Reuters, Microsoft plans to build and distribute its own quantum computer within the next few years — we are no longer discussing a threat that is decades away. Other companies involved in the deployment of quantum architecture are also intensifying their efforts. The mid-April rally, sparked by the release of the Nvidia Ising AI model, has reinforced the market's belief that the systems are moving from experimental labs to commercial data centers, placing related companies among the top stock gainers.

For now, Bitcoin is not facing an immediate security crisis, but there is a genuine risk that in the near future, hackers may be able to create fake digital signatures and then transfer coins from vulnerable wallets — particularly older addresses — or those where public keys have been reused or disclosed.

Specifically, Google states that the "cost" that a hacker would have to pay to execute a quantum attack on the elliptical curve cryptography may actually be lower than previously anticipated. The paper indicates that an attack could be executed in "minutes" using a high-speed architecture with fewer than 500,000 physical qubits.

Bitcoin employs digital signatures to validate ownership. When (and if) a quantum computer can successfully reverse-engineer a user's private key using their public key, the threat is not to the "entire blockchain" at once, but to specific, high-risk wallets. According to the white paper, approximately 6.7 million BTC are stored in wallets vulnerable to what the authors call "at-rest" attacks. These are primarily addresses where the public key is already visible on-chain or those that have been used multiple times.

The paper clearly differentiates between mining and signature threats. Quantum attacks on PoW (Proof-Of-Work) are unlikely to be viable for the next few decades, and they even refer to "quantum mining" at the present time as "more science fiction than real threat." The primary risk stems from signatures — the proof of ownership — rather than the daily operations of the network.

Therefore, the health of the Bitcoin Network is not fated for collapse, provided institutions take preventative measures. And they are already doing it. NIST has issued post-quantum standards, and major technology companies are beginning to offer compliant tools. For example, The United Kingdom's National Cyber Security Center has outlined milestones for 2028, 2031, and 2035, while Google Cloud KMS has documented PQC digital signatures including ML-DSA and SLH-DSA. These are examples of how the security infrastructure that will serve as the foundational building block for future quantum migrations is already being developed.

As for Bitcoin specifically, BIP-360 represents a significant step forward. BIP-360 is a draft proposal for creating a new output format referred to as Pay-to-Merkle-Root, intended to eliminate one of the primary pathways for long-exposure quantum attacks. That said, while BIP-360 removes one pathway, full protection against fast-moving quantum attacks will likely require true post-quantum signatures.

In summary, for now, your Bitcoin is safe. However, the long-term security risks are real and require years of preparation. While standards, guidelines, and preliminary technical proposals exist, the transition will be difficult, slow, and contentious. Why? Because it affects users' wallets, custodianship, UX, costs, and protocol governance.

In the short term, there is a reputational risk associated with transitioning to quantum computing. There will undoubtedly be additional research published in the coming months highlighting similar types of vulnerabilities — not only in crypto. It will be interesting to watch how the Bitcoin price reacts and whether any type of correlation emerges — perhaps a quantum one.