In a recent research note, Grayscale, a digital asset management firm, expressed support for expedited efforts to make public blockchains resistant to quantum computing. The note emphasizes that while the technical solutions to achieve this are already available, the more significant challenge is in convincing decentralized communities to adopt 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 could potentially be achieved with fewer than 500,000 physical qubits, a significant reduction from prior estimates, and could be executed in under nine minutes once the necessary machinery is in place.
An analysis by CoinDesk found that such an attack would give the attacker a roughly 41% chance of stealing funds before a Bitcoin transaction is confirmed. Grayscale highlighted several key points from the Google research, including the potential for progress toward a cryptographically relevant quantum computer to occur in sudden leaps rather than gradually, making timelines difficult to predict. Additionally, the note pointed out that post-quantum cryptography is already mature and in use to secure internet traffic and certain blockchain transactions, and that the quantum risk varies significantly across different blockchains depending on their specific characteristics.
From a purely technical standpoint, Bitcoin is argued to have a 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, a more complex issue is what to do with 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 creator, Satoshi Nakamoto.
This dilemma raises questions about whether these coins should be burned, left untouched, or have their spending rate limited to prevent potential exploitation. Binance co-founder Changpeng Zhao recently raised similar concerns, suggesting that if Satoshi's coins were to move during a migration, it could indicate that Satoshi is still active, and if they do not move, it might be preferable to lock or effectively burn those addresses.
Grayscale outlines these options but notes that the Bitcoin community has a history of contentious debates over protocol changes, which could complicate the decision-making process. In contrast, Ethereum faces its own set of challenges, with Google's paper identifying multiple attack vectors worth over $100 billion in combined exposure.
An Ethereum Foundation researcher estimated a 10% chance of quantum key recovery by 2032, highlighting the urgency of addressing quantum migration timelines.