A Google Quantum AI engineer has shown that a quantum computer with less than a million qubits could break a 2048-bit RSA key in less than a week, compared to the previously estimated 20 million.
Although Bitcoin does not use RSA but ECC, this cryptography is also vulnerable to quantum algorithms, especially Shor’s.
Concrete experiments are already underway, with a reward of 1 BTC promised to break a 1 to 25-bit ECC key using a quantum computer.
A Google researcher reignites the quantum threat on Bitcoin
A Google Quantum AI researcher has dramatically reduced the resources needed to break RSA encryption using a quantum computer. This discovery forcefully rekindles the debate on the resilience of cryptographic systems… including those securing crypto wallets.
RSA vulnerable, Bitcoin concerned by ricochet
Craig Gidney, an engineer at Google, now believes that a quantum computer equipped with less than a million qubits, even noisy ones, could break a 2048-bit RSA key in less than a week. This is twenty times fewer resources than his 2019 estimates, which then mentioned 20 million qubits for a calculation time of eight hours.
If Bitcoin doesn’t use RSA but ECC (elliptic curve cryptography), the core issue remains the same: both systems rely on calculations that quantum algorithms like Shor’s could theoretically solve much faster than a classical computer.
Bitcoin’s ECC is not immune
ECC operates differently: it is based on mathematical curves instead of very large numbers, allowing for equivalent security with a much smaller key size. However, the arrival of quantum computing does not adhere to traditional power ratios. Even 256-bit ECC keys, considered very secure today, could succumb to a sufficient number of stable qubits.
The threat remains theoretical for now. No quantum processor approaches the numbers mentioned. The most advanced, IBM’s Condor, tops out at 1,121 qubits, and Google Sycamore at only 53. But the pace of discoveries is accelerating.
Real-world tests already underway
The research group Project 11 is already exploring the possibility of breaking very small ECC keys using current quantum machines. A public reward of 1 BTC, approximately $110,000, is even promised to anyone who can break a key between 1 and 25 bits using a quantum computer.
Goal: to test the actual proximity between current quantum hardware limits and potential weaknesses in existing cryptosystems.
