In a recent research note, Grayscale emphasized the need to expedite efforts to make public blockchains resistant to quantum computing, citing the existence of technical solutions but highlighting the difficulty in achieving consensus among decentralized communities. This follows a week of industry response to a Google Quantum AI paper, which found that breaking bitcoin's elliptic curve cryptography could be achieved with fewer than 500,000 physical qubits and executed in approximately nine minutes. The paper's findings have sparked concerns, with CoinDesk's analysis suggesting a 41% chance of an attacker stealing funds before a bitcoin transaction confirms. Grayscale's note outlines four key takeaways from the Google research, including the potential for progress toward a cryptographically relevant quantum computer to occur in unpredictable jumps, the maturity of post-quantum cryptography, varying quantum risk across blockchains, and the lower quantum risk of bitcoin due to its UTXO model and proof-of-work consensus.
However, the note also highlights the challenge of addressing the approximately 6.9 million BTC in wallets with permanently exposed public keys, including an estimated 1 million belonging to Satoshi Nakamoto. Possible solutions include burning these coins, doing nothing, or limiting their release rate, but the bitcoin community's history of contentious debates over protocol changes poses a significant obstacle.
In contrast, Ethereum faces separate attack vectors worth over $100 billion in combined exposure, with the Ethereum Foundation researcher estimating a 10% chance of quantum key recovery by 2032.