Google's Willow chip deepens quantum threat to bitcoin

Google says its Willow chip can prepare the special quantum states needed for advanced calculations with about 40 times fewer errors, reducing one of the hardware bottlenecks behind any future attempt to derive private keys from exposed public keys on bitcoin. The advance intensifies the long-running quantum threat to Satoshi-era and long-dormant addresses, where roughly 6.9 million bitcoin are estimated to sit at wallets with compromised public keys.

The Willow breakthrough adds fresh urgency to the industry's post-quantum migration planning, which has ramped up across recent months even as no quantum computer capable of the attack yet exists. Google's announcement is a hardware-side data point separate from earlier warnings about wallet vulnerabilities from researchers and regulators.