Cracking Bitcoin in just 9 minutes? Google warns that the end of elliptic encryption may come sooner than expected, having lowered the attack threshold by 20 times.

According to 1M AI News monitoring, a Google Quantum AI team released a white paper showing major optimizations to Shor’s algorithm. Shor’s algorithm can break the elliptic curve encryption used by Bitcoin and Ethereum; once quantum computers are powerful enough, attackers can derive a private key from a public key and steal funds. The team compiled two sets of attack circuits, requiring fewer than 1200 and fewer than 1450 logical qubits respectively (computing units formed by hundreds of physical qubits with error correction). On superconducting quantum computers, both circuits can complete the computations within a few minutes under the condition of fewer than 500,000 physical qubits. Previously, the mainstream estimate in academia was about 10 million physical qubits; this breakthrough lowers the threshold by roughly 20x.

Attackers can complete most of the preparatory computation in advance and crack the private key about 9 minutes after a Bitcoin transaction is broadcast. Bitcoin’s average block time is about 10 minutes, giving attackers about a 41% chance to intercept funds before the transaction is confirmed. Currently, about 6.9 million Bitcoin (about one-third of the total supply) face potential risk because their public keys have been exposed, including about 1.7 million from the network’s early days. Google also noted that the 2021 Taproot upgrade exposes public keys by default, which may further expand the scope of vulnerable wallets.

The team did not publicly disclose the specific implementation of the attack circuits, but instead released a zero-knowledge proof that allows third parties to verify the correctness of the conclusion without revealing the attack method. Google’s Quantum Algorithms Research Director Ryan Babbush and Google Quantum AI Engineering Vice President Hartmut Neven said the team had communicated with the U.S. government before publishing and is now collaborating with Coinbase, the Stanford Blockchain Research Institute, and the Ethereum Foundation to advance post-quantum migration. Google previously set 2029 as the deadline for migrating its own certified services to post-quantum encryption. Castle Island Ventures co-founder Nic Carter called the paper “highly alarming” and wrote: “Elliptic curve cryptography is on the edge of being obsolete. Whether it’s 3 years or 10 years, it’s over—we need to accept that.”