Grayscale, a prominent digital asset manager, has released a research note advocating for accelerated efforts to enhance public blockchains' resistance to quantum computing. The note emphasizes that although technical solutions to this challenge already exist, the more daunting task lies in 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 compromising bitcoin's elliptic curve cryptography would require fewer than 500,000 physical qubits, a significant reduction from prior estimates, and could be accomplished in approximately nine minutes. The study found that such an attack would give an attacker a roughly 41% chance of stealing funds before a bitcoin transaction is confirmed.
Grayscale's research highlights four key takeaways from Google's findings, including the potential for progress toward a cryptographically relevant quantum computer to occur in sudden leaps rather than gradual increments, rendering timelines unpredictable. Additionally, the note underscores that post-quantum cryptography is already mature and in use for securing 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 technical standpoint, Grayscale argues that bitcoin possesses a lower quantum risk compared to other chains due to its utilization of a UTXO model, proof-of-work consensus, absence of native smart contracts, and specific address types that are not vulnerable to quantum attacks if not reused after spending. However, the more complex issue at hand is determining the course of action for the approximately 6.9 million BTC stored in wallets with publicly exposed keys on the blockchain, including an estimated 1 million believed to belong to bitcoin's pseudonymous creator, Satoshi Nakamoto.
This dilemma has also been raised by Binance co-founder Changpeng Zhao, who suggested that if Satoshi's coins are moved during a migration, it would indicate that he is still active, and if they remain unmoved, 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 – but notes that the bitcoin community has a history of contentious debates over protocol changes, citing last year's dispute surrounding image data stored in blocks. In contrast, Ethereum faces distinct challenges, with Google's paper identifying five separate attack vectors worth over $100 billion in combined exposure.
Ethereum Foundation researcher Justin Drake estimates at least a 10% chance of quantum key recovery by 2032, prompting the foundation to stake aggressively, although it has not publicly disclosed its quantum migration timelines.