What Does Google's Quantum Computing Chip Mean for Bitcoin?

Google’s new quantum computing chip could mean bitcoin (BTC) is finished. <a href="https://x.com/search?q=bitcoin%20dead%20quantum%20computing&src=typed_query" target="_blank">That was the sentiment</a> for some on Monday as the internet giant unveiled Willow, a quantum supercomputer that can perform certain computational tasks in just five minutes that would take classical supercomputers an astronomical amount of time—specifically, 10 septillion years (or one followed by 24 zeroes; a trillion trillion). 10,000,000,000,000,000,000,000,000. Such an amount of time is greater than the existence of the entire universe at 13.8 billion years. In superficial theory, such a powerful computer could mean no passwords are safe, encrypted messages are intercepted, nuclear weapons codes are found out, and almost anything can be unlocked by brute-forcing combinations of numbers and letters. But it isn’t all a doom and gloom yet. While quantum computing does indeed pose significant threats to current security systems, it's not a master key to the universe, atleast not right now. And there is no looming threat to Bitcoin, either. Quantum computing leverages the principles of quantum mechanics, using quantum bits or qubits instead of traditional bits. Unlike bits which represent either a 0 or 1, qubits can represent both 0 and 1 simultaneously due to quantum phenomena like superposition and entanglement. This allows quantum computers to perform multiple calculations at once, potentially solving problems that are currently intractable for classical computers. Willow uses 105 qubits and demonstrates an exponential error reduction as the number of qubits increases. This is a critical step towards building a practical, large-scale quantum computer, per CEO Sundar Pichai.

Bitcoin uses algorithms like <a href="https://www.coindesk.com/learn/how-bitcoin-mining-works" target="_blank">SHA-256 for mining</a> and <a href="https://en.bitcoin.it/wiki/Elliptic_Curve_Digital_Signature_Algorithm" target="_blank">ECDSA for signatures</a>, which might be vulnerable to quantum decryption. And the short answer is that quantum computers, even advanced ones like Google's Willow, do not possess the scale or error correction capabilities needed to immediately decrypt widely used encryption methods like RSA, ECC (used in Bitcoin transactions), or AES (used in securing data).

If quantum computers like Willow reach a scale where they can easily factor in large numbers, they could potentially break these encryption schemes, compromising wallet security and transaction integrity. That would require quantum computers with millions or even billions of “qubits” with extremely low error rates, far beyond the current technology. “Google claims to have demonstrated "below threshold" error correcting capabilities with their latest quantum chip,” said Chris Osborn, founder at Solana ecosystem project Dialect, in an X post. "Below threshold" is industry jargon for turning physical qubits, which are noisy, shitty quantum bits that are basically useless, into "logical" qubits, which are multi-qubit abstractions that correct for errors & let you actually perform real computation.” he added. “5,000-ish logical qubits are needed to run Shor's algorithm to break encryption. In other words, *millions* of physical qubits are needed to break encryption. Google's chip today: 105 physical qubits,” Osborn noted. Until then, cryptocurrencies (and other sectors) have time to develop quantum-resistant algorithms. Ethereum co-founder Vitalik Buterin, among others, is part of an industry cohort that has been <a href="https://vitalik.eth.limo/general/2024/10/14/futures1.html" target="_blank">calling for updated security procedures</a> and tools in a quantum computing world.

“Quantum computing experts such as Scott Aaronson have also recently started taking the possibility of quantum computers actually working in the medium term much more seriously,” Buterin wrote in an October technical blog. “This has consequences across the entire Ethereum roadmap: it means that each piece of the Ethereum protocol that currently depends on elliptic curves will need to have some hash-based or otherwise quantum-resistant replacement.” “This justifies conservatism in the assumptions around performance of proof-of-stake designs, and also is a cause to be more proactive to develop quantum-resistant alternatives,” he added at the time. Try another day, crypto naysayers.