Google researchers have demonstrated a new method for quantum computing, published in Science on October 15. The technique, called magic state cultivation, was tested on the company's Willow chip and reduced errors by approximately 40-fold. This process achieved a record 99.99% fidelity by filtering out failed operations, which could significantly decrease the physical size requirements for future quantum machines.
The development is relevant to Bitcoin security, as a sufficiently powerful quantum computer could theoretically derive private keys from public keys. Google previously estimated that such an attack would require fewer than 500,000 qubits. The current Willow chip contains 105 qubits, and Google noted that scaling the cultivation method remains a significant technical challenge with no established timeline.
Data from Glassnode indicates that 6.04 million BTC, representing 30.2% of all mined Bitcoin, are held in addresses with visible public keys. While many coins can be moved to secure addresses, a June study suggests that approximately 2.3 million BTC are inaccessible or dormant. Coinbase has initiated discussions on potential quantum-resistant security measures, including a possible migration process for active wallets.
The June study proposed that a migration to quantum-resistant security could begin in 2026 and conclude between 2029 and 2031. This timeline is intended to precede the potential arrival of a code-breaking quantum computer, which some projections estimate could emerge by 2035. Google has not provided a specific schedule for scaling its current error-reduction technology.
