TLDR
- Google Quantum AI reduced errors 40-fold on its Willow processor using magic state distillation.
- Researchers achieved 99.99% logical fidelity, but retained only 8% of attempts.
- Google’s earlier research estimated that future quantum attacks could threaten Bitcoin’s digital signatures.
- Coinbase urged Bitcoin developers to prepare quantum-resistant security upgrades before future attacks become practical.
- Starknet opened a governance vote as it explores becoming an independent, quantum-resistant blockchain.
Google Quantum AI reported a new test on its Willow processor on Thursday, reducing errors in a key quantum operation by 40 times. The findings also revived Bitcoin security concerns.
Google Quantum Test Reaches 99.99%, State Fidelity
The study, published in Science on October 15, tested a process called magic state cultivation. Willow produced special quantum states with 99.99% logical fidelity.
Quantum computers need these states for complex calculations. Earlier estimates suggested their production could consume up to 95% of a machine’s capacity.
Google filtered out faulty states through repeated checks on Willow. Just 8% passed. Researchers successfully transferred the remaining states between two error-correction methods, although larger tests are still needed.
Bitcoin Faces a Longer-Term Quantum Risk
In March, Google Quantum AI researchers estimated that a future machine might break Bitcoin’s current signature protection using fewer than 500,000 physical qubits. The calculation assumed future hardware, not a successful attack.
The researchers described a possible nine-minute attack against transactions with exposed public keys. About 6.9 million BTC may face exposure through already visible public keys.
Other networks are also debating protections. Cardano founder Charles Hoskinson challenged Vitalik Buterin’s concerns about AI-assisted attacks on lattice cryptography in an October 9 X post, arguing that security choices require evidence.
Coinbase Calls for Early Bitcoin Preparation
Coinbase published a security paper on October 13 urging developers to plan before quantum attacks become practical. It called Bitcoin’s eventual transition a multiyear effort.
Its recommendations include examining BIP-360, which changes how certain Bitcoin transactions reveal keys. Coinbase also discussed wallets that could support existing and newer signature methods during a transition.
In its Bitcoin quantum security plan, Coinbase cited limited block space, custody systems and dormant coins as unresolved problems. Owners who have lost access to their wallets may be unable to move funds when upgrades become available.
Other Networks Review Their Security Plans
Starknet said on X that it was considering becoming an independent blockchain, with a goal of reaching quantum resistance in 2027. Its account has more than 350,000 followers.
On October 15, Starknet opened a nonbinding vote on whether to study that change. The vote runs through October 22 and does not authorize a network move. Google has separately set a 2029 target for its own cryptography transition.
