In a recent research note, Grayscale, a digital asset management firm, expressed support for expedited efforts to enhance the quantum resistance of public blockchains. The note emphasizes that although the technical solutions to achieve this are already available, the more significant obstacle is securing agreement among decentralized communities to implement these solutions.
This comes on the heels of a week-long industry response to a paper by Google Quantum AI, which revealed that breaking Bitcoin's elliptic curve cryptography would require fewer than 500,000 physical qubits, a significant reduction from previous estimates, and could be accomplished in approximately nine minutes. CoinDesk's analysis of the paper found that such an attack would give an attacker a roughly 41% chance of stealing funds before a Bitcoin transaction is confirmed.
Grayscale highlighted four key takeaways from the Google research, including the potential for progress toward a cryptographically relevant quantum computer to occur in discrete jumps, rendering timelines unpredictable. Additionally, the firm noted that post-quantum cryptography is already mature and in use to secure internet traffic and certain blockchain transactions, and that quantum risk varies significantly across different blockchains based on their transaction models, consensus mechanisms, and block times. From a purely engineering perspective, Bitcoin is argued to have lower quantum risk compared to other chains due to its use of a UTXO model, proof-of-work consensus, lack of native smart contracts, and specific address types that are not vulnerable to quantum attacks if not reused after spending. However, the more challenging question revolves around the handling of approximately 6.9 million BTC in wallets with publicly exposed keys on the blockchain, including an estimated 1 million believed to belong to Bitcoin's pseudonymous creator, Satoshi Nakamoto.
Binance co-founder Changpeng Zhao recently posed a similar question, suggesting that if Satoshi's coins were to move during a migration, it would indicate that Satoshi is still active, and if they do not move, it might be preferable to lock or effectively burn those addresses. Grayscale presents similar options - burning the coins, taking no action, or deliberately slowing their release by limiting the spending rate from vulnerable addresses.
Nonetheless, the firm acknowledges that the Bitcoin community has a history of contentious debates over protocol changes, citing last year's dispute over image data stored in blocks as an example. The situation contrasts with Ethereum, which, according to Google's paper, faces five separate attack vectors worth over $100 billion in combined exposure.
Ethereum Foundation researcher Justin Drake estimated a 10% chance of quantum key recovery by 2032, prompting the foundation to stake aggressively, though it has not publicly addressed quantum migration timelines.