Grayscale, a digital asset management firm, has released a research note emphasizing the need to accelerate efforts in making public blockchains resistant to quantum computing. The note posits that although technical solutions to this issue already exist, the greater obstacle lies in reaching a consensus among decentralized communities to implement these solutions. This comes after a week of intensive industry discussions following Google Quantum AI's publication of a paper, which revealed that breaking bitcoin's elliptic curve cryptography could be achieved with fewer than 500,000 physical qubits, significantly lowering the estimated threshold. The paper also indicated that such an attack could be executed in approximately nine minutes, giving an attacker about a 41% chance of stealing funds before a bitcoin transaction is confirmed.
Grayscale highlighted several key takeaways from Google's research, including the potential for progress toward a cryptographically relevant quantum computer to occur in unpredictable, discrete jumps, and the maturity of post-quantum cryptography, which is already being used to secure certain blockchain transactions and internet traffic. The research also noted that the quantum risk varies significantly among different blockchains, depending on their transaction models, consensus mechanisms, and block times. From a purely technical standpoint, it was argued that bitcoin has a lower quantum risk compared to other chains due to its UTXO model, proof-of-work consensus, lack of native smart contracts, and the use of certain address types that are not vulnerable to quantum attacks if not reused after spending. However, the more challenging question revolves around the approximately 6.9 million BTC in wallets with publicly exposed keys on the blockchain, including an estimated 1 million believed to belong to Satoshi Nakamoto.
The options for addressing this issue include burning these coins, taking no action, or deliberately slowing their release by limiting the spending rate from vulnerable addresses. Grayscale noted that the bitcoin community has historically been divided over protocol changes, citing last year's debate over image data stored in blocks. In contrast, Ethereum faces different challenges, with Google's paper identifying five attack vectors worth over $100 billion in combined exposure. An Ethereum Foundation researcher estimated a 10% chance of quantum key recovery by 2032, underscoring the need for quantum migration planning.