- Google estimates show that fewer than 500,000 qubits could break crypto encryption.
- According to the report, real-time attacks may hijack Bitcoin transactions within nine minutes.
- Taproot’s public key visibility could expose and expand the pool of vulnerable Bitcoin wallets.
According to Google, breaking encryption and security on Bitcoin and Ethereum may require fewer quantum resources than earlier estimates suggested.
Researchers estimate that about 500,000 physical qubits could be used to compromise current cryptographic systems. Previous projections often placed this threshold in the millions, creating a perception of distant risk timelines.
Additionally, the study outlines that practical attacks may require only 1,200 to 1,450 high-quality qubits. This lower barrier narrows the gap between theoretical quantum capabilities and real-world execution scenarios.
Real-Time Transaction Exploits Emerge
The research introduces a model where attackers target transactions during processing rather than dormant wallets. This approach shifts focus toward in-flight vulnerabilities rather than static exposures.
When a Bitcoin transaction is broadcast, a public key becomes briefly visible. A sufficiently advanced quantum system could derive the private key and redirect funds before confirmation completes.
According to the study, such an attack could be executed within nine minutes. Given Bitcoin’s average confirmation time of around ten minutes, this creates a success probability near 41%.
“Real-time quantum attacks could intercept Bitcoin transactions mid-flight. Timing becomes the critical vulnerability.”
The new Crypto Whitepaper shows that Ethereum may face less exposure to this specific scenario due to faster confirmation speeds. Shorter processing windows reduce the opportunity for quantum computation to complete within the attack timeframe.
Taproot Upgrade Expands Exposure Surface
The study also shows that Bitcoin’s Taproot upgrade was introduced in 2021 to improve transaction efficiency and privacy. However, it altered how public keys appear on-chain by making them visible by default, without any protective layer.
Previously, public keys were revealed only after a transaction was spent, limiting exposure duration.
This design change increases the number of wallets potentially vulnerable to quantum attacks. The research estimates that approximately 6.9 million Bitcoins already sit in addresses with exposed keys.
That figure includes around 1.7 million Bitcoin from early network activity and funds affected by address reuse. These conditions create a larger attack surface compared to earlier security assumptions.
Migration Pressure and Research Disclosure
The findings align with earlier projections from Google suggesting that meaningful quantum systems could emerge before 2029. This timeline underscores the urgency of cryptographic migration strategies.
Researchers emphasize that quantum attacks are not imminent; they require preparation, and timelines may need to be adjusted across the ecosystem.
The study used zero-knowledge proof techniques to allow verification of results without exposing detailed attack methods.
As a result, the discussion shifts toward readiness rather than immediate threat execution. Market participants are now assessing timelines with updated technical benchmarks rather than earlier assumptions.