Google Cuts Magic-State Errors 40-Fold on Willow Quantum Processor
Google Quantum AI said magic state cultivation cut errors about 40-fold on its Willow processor and reached 99.99% logical fidelity in T-states, in a paper published in Science.
Why it matters
Magic state production can absorb up to 95% of a quantum computer's capacity by Google's account, so a 40-fold error cut bears on when machines reach the scale Google's March study modeled for secp256k1 key recovery, fewer than 500,000 physical qubits. Bitcoin.com News said wallets with already-exposed public keys are the exposed ones, Crypto.News reported Coinbase's October 13 migration guidance, and U.Today said the method has not reached a scale that threatens current cryptocurrencies.
Where the sources disagree
Amount of bitcoin exposed through public keys
approximately 6.9 million BTC
Crypto News (CryptoNews.net)
6.04 million BTC (30.2% of mined bitcoin)
Crypto.News
Crypto News reported about 6.9 million BTC could face exposure through publicly revealed keys, while Crypto.News cited Glassnode for 6.04 million BTC with exposed keys, equal to 30.2% of mined bitcoin.
Key facts
Google Quantum AI said magic state cultivation cut quantum state errors about 40-fold on its Willow processor.
40 foldReported by Bitcoin.com News
The researchers reported T-states at a record logical fidelity of 99.99%.
99.99 %Reported by Bitcoin.com News
An earlier preprint reported an injection-only logical error probability of about 0.44% against a cultivated-state error upper bound of about 0.01%.
0.01 %Reported by Crypto News (CryptoNews.net)
Cultivation prepared a single logical qubit on Willow, which contains 105 physical qubits.
105 qubitsReported by Crypto News (CryptoNews.net)
Google says some estimates put the cost of producing magic states at up to 95% of a quantum computer's capacity.
95 %Reported by Decrypt
Google's March resource study modeled breaking the secp256k1 cryptography behind bitcoin signatures with fewer than 500,000 physical qubits.
500,000 qubitsReported by Crypto News (CryptoNews.net)
Crypto.News cited Glassnode for 6.04 million BTC with exposed public keys, 30.2% of mined bitcoin, while Crypto News reported about 6.9 million BTC could face exposure through publicly revealed keys.
6,040,000 BTCDisputed figureReported by Crypto News (CryptoNews.net)
What happened
Google Quantum AI announced on Thursday, 15 October 2026 that magic state cultivation cut errors about 40-fold on the Willow quantum processor, with the results running in Science the same day. The researchers reported T-states at a record logical fidelity of 99.99%, and Crypto News cited an earlier preprint giving an injection-only logical error probability of about 0.44% against a cultivated-state upper bound near 0.01%. U.Today reported that Sundar Pichai presented the result, while Crypto News said cultivation prepared a single logical qubit on a Willow chip of 105 physical qubits and Decrypt said some estimates put magic state production at up to 95% of a machine's capacity. The bitcoin link rests on Google's March study, which Crypto News and Crypto.News both describe as breaking the secp256k1 cryptography behind transaction signatures with fewer than 500,000 physical qubits and roughly nine minutes of runtime once a public key is exposed, and Crypto News says the study's two circuit designs need up to 1,200 logical qubits with 90 million Toffoli gates, or up to 1,450 logical qubits with 70 million. Estimates of the exposed supply differ, with Crypto News reporting about 6.9 million BTC reachable through revealed public keys and Crypto.News citing Glassnode for 6.04 million BTC, 30.2% of mined bitcoin. Crypto.News reported Coinbase published bitcoin migration recommendations on October 13, Bitcoin.com News said quantum-resistant upgrades to the network run into technical and coordination problems, Google acknowledged that significant technical challenges remain as Crypto News reported, and U.Today said the method has not been shown at a scale that would threaten current cryptocurrencies.
How the story developed
- Official statement
Google Quantum AI announces magic state cultivation results in Science
Google Quantum AI said magic state cultivation on Willow cut errors about 40-fold and produced T-states at 99.99% logical fidelity; Crypto.News dates the announcement to October 15, 2026.
- First report
First report by Bitcoin.com News
Google Touts ‘Magic’ Quantum Breakthrough as Bitcoin Q-Day Threat Looms
- Update
First crypto outlet report of the Google announcement
Bitcoin.com News published the story on Thursday evening, framing the result against a possible bitcoin Q-Day.
- Official statement
Google publishes resource study on breaking secp256k1
Crypto News and Crypto News's later piece report a March analysis modeling secp256k1 attacks at fewer than 500,000 physical qubits and about nine minutes of runtime; Crypto News also reports it as roughly 20 times fewer qubits than some earlier estimates.
- Independent corroboration
Independently corroborated by Decrypt
Google Says It Just Cracked One of Quantum Computing's Biggest Bottlenecks
- Update
Google's 2025 estimate for breaking RSA-2048
Decrypt and its syndicated copy report that cultivation is one of the tricks behind Google's 2025 estimate that RSA-2048 could fall to under a million noisy qubits, with code-breaking needing magic states at errors near one in 10 billion.
- Update
Competing figure for bitcoin with exposed public keys
Crypto.News attributes6.04 million BTC with exposed keys, 30.2% of mined supply, to Glassnode, against the roughly 6.9 million BTC reported by Crypto News.
- Official statement
Coinbase publishes bitcoin security and migration recommendations
Crypto.News reported Coinbase addressed migration challenges and vulnerable legacy coins; the evidence does not give a year.
How coverage built up
Independent sources over time, counted the way the consensus panel counts them: a republication of a wire story does not move the line.
- 15 Oct 2026, 19:38 UTC: Bitcoin.com News, official — 1 independent source, 1 reports
- 15 Oct 2026, 21:46 UTC: Decrypt — 2 independent sources, 3 reports
- 16 Oct 2026, 05:01 UTC: Crypto News (CryptoNews.net) — 3 independent sources, 5 reports
- 16 Oct 2026, 09:23 UTC: Crypto.News — 4 independent sources, 6 reports
- 16 Oct 2026, 18:42 UTC: U.Today — 5 independent sources, 7 reports
Affected entities
Original sources
| Publisher | Report | Role | Published |
|---|---|---|---|
| Bitcoin.com News Company, official | Google Touts ‘Magic’ Quantum Breakthrough as Bitcoin Q-Day Threat Looms | Original | |
| Decrypt Crypto media | Google Says It Just Cracked One of Quantum Computing's Biggest Bottlenecks | Independent | |
| Crypto.News Crypto media | Google cuts quantum errors 40-fold: Is Bitcoin at risk? | Independent | |
| U.Today Crypto media | Google's Quantum Breakthrough Sparks Fresh Crypto Security Concerns | Syndicated | |
| Crypto News (CryptoNews.net) Aggregator | Google Touts 'Magic' Quantum Breakthrough as Bitcoin Q-Day Threat Looms | Syndicated | |
| Crypto News (CryptoNews.net) Aggregator | Google Says It Just Cracked One of Quantum Computing's Biggest Bottlenecks | Syndicated | |
| Crypto News (CryptoNews.net) Aggregator | Google Cuts Quantum Magic-State Errors 40-Fold on Willow | Syndicated |
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