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.

ME News message, on March 31 (UTC+8), Google’s quantum AI team released a white paper showing major optimizations to Shor’s algorithm. Shor’s algorithm can break the elliptic curve cryptography used by Bitcoin and Ethereum—once a quantum computer is powerful enough, an attacker can derive the private key from the public key and steal funds. The team compiled two sets of attack circuits, each requiring fewer than 1200 and fewer than 1450 logical qubits (computation units composed of hundreds of physical qubits together with error correction). On superconducting quantum computers, both circuits can complete the computation within 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 computations in advance, cracking the private key within about 9 minutes after Bitcoin transaction 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 Bitcoins (about one-third of the total supply) face potential risk because their public keys have already 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 implementations of the attack circuits, and instead released a zero-knowledge proof that allows third parties to verify that the conclusion is correct without revealing the attack method. Ryan Babbush, Director of Research for Google’s Quantum Algorithms, and Hartmut Neven, Vice President of Engineering at Google Quantum AI, said the team had already communicated with the U.S. government before releasing the work, and is now collaborating with Coinbase, the Stanford Blockchain Research Institute, and the Ethereum Foundation to advance migration to post-quantum cryptography. Google previously set 2029 as the deadline for migrating its own certified services to anti-quantum encryption. Nic Carter, co-founder of Castle Island Ventures, called the paper “very alarming,” and wrote: “Elliptic curve cryptography is on the verge of being obsolete. Whether it’s 3 years or 10 years, it’s done—we need to accept that.” (Source: 1M AI News )