Google Researcher Reveals Quantum Computing Could Potentially Break Bitcoin-Like Encryption More Easily Than Initially Thought

Research conducted by Google Quantum AI researcher Craig Gidney indicates that breaking RSA encryption, widely used to secure data, may necessitate 20 times fewer quantum resources than previously estimated. Although the study does not specifically mention Bitcoin or other cryptocurrencies, it targets the encryption methods that form the backbone of crypto wallets and certain transactions. RSA, a public-key encryption algorithm, relies on a pair of linked keys: a public key for encryption and a private key for decryption.

While Bitcoin utilizes elliptic curve cryptography (ECC) instead of RSA, ECC can also be compromised by Shor's algorithm, a quantum algorithm designed to factor large numbers and solve logarithm problems. ECC employs mathematical calculations called curves to lock and unlock digital data, offering a smaller yet equally strong key. Although 256-bit ECC keys are more secure than 2048-bit RSA keys, quantum threats escalate nonlinearly, and research like Gidney's accelerates the timeline for potential attacks. Gidney estimates that a 2048-bit RSA integer could be factored in under a week by a quantum computer with fewer than one million noisy qubits, a significant revision from his 2019 paper.

Currently, no such machine exists, with IBM's most powerful quantum processor, Condor, having just over 1,100 qubits, and Google's Sycamore having 53. Quantum computing leverages quantum mechanics principles, utilizing qubits that can represent both 0 and 1 simultaneously due to phenomena like superposition and entanglement. This enables quantum computers to perform multiple calculations simultaneously, potentially solving problems that are currently intractable for classical computers.

The 20-fold decrease in the number of qubits required may reflect algorithmic trends applicable to ECC as well. Researchers are actively exploring whether weakened versions of Bitcoin's encryption can be broken by current quantum hardware, with some offering bounties to measure the proximity of current systems to achieving this goal.