Google's latest quantum computing research reveals that cracking the RSA encryption protecting Bitcoin wallets will require around 1 million qubits, a substantial reduction from the previous estimate of 20 million qubits. This breakthrough by Google Quantum Researcher Craig Gidney cuts down the effort required to break a 2048-bit RSA key from eight hours on a 20 million-qubit machine to less than a week on a machine with fewer than 1 million qubits.
The improvement is due to faster algorithms and more efficient error correction techniques, including a method called "magic state cultivation," which enhances the accuracy and resource efficiency of quantum computations. While today's quantum computers, such as IBM's Condor with 1,121 qubits and Google's Sycamore with 53 qubits, remain far from this scale, the pace of advancement highlights growing risks to cryptographic security systems.
Bitcoin relies on elliptic curve cryptography (ECC), similar in mathematical foundation to RSA. Experts warn that the accelerated quantum threat to RSA could foreshadow a sooner-than-expected vulnerability for Bitcoin's ECC-based security. Although Bitcoin’s 256-bit encryption is currently stronger than RSA 2048-bit keys, the exponential growth in quantum capabilities may erode this protection.
Despite the looming threat, some industry voices note potential benefits, such as recovering lost Bitcoin wallets. Projects like Project 11 are already exploring quantum attacks on Bitcoin’s cryptography, offering incentives like the Q-Day Prize to encourage breakthroughs. Meanwhile, entities like Solana and Ethereum are developing quantum-resistant solutions to safeguard user assets.
Industry experts emphasize the urgency of transitioning to quantum-safe cryptographic methods to mitigate future risks. Google has proactively enhanced its own encryption, adopting updated quantum-resistant standards in products like Chrome. This discovery underscores the delicate balance between advancing quantum computing power and maintaining the security of digital assets and global secure communications.