Grayscale, a digital asset management firm, has published a research note advocating for expedited efforts to enhance public blockchains' resistance to quantum computing. The note emphasizes that although the necessary technical solutions are already available, the more daunting task lies in securing agreement among decentralized communities to implement these solutions. This follows a week of industry-wide response to a paper by Google Quantum AI, which determined that compromising bitcoin's elliptic curve cryptography would necessitate fewer than 500,000 physical qubits and could be accomplished in approximately nine minutes.
The research highlights four key takeaways from Google's study, including the potential for rapid progress in quantum computing capabilities, the maturity of post-quantum cryptography in securing internet traffic and certain blockchain transactions, and the variation in quantum risk across different blockchains. Grayscale's research underscores that from a purely technical perspective, bitcoin's use of a UTXO model, proof-of-work consensus, and lack of native smart contracts contributes to its relatively lower quantum risk. However, the more complex issue revolves around addressing the roughly 6.9 million BTC in wallets with publicly exposed keys on the blockchain, including an estimated 1 million coins believed to belong to Satoshi Nakamoto.
The options for handling these vulnerable coins include burning them, taking no action, or slowing their release by limiting spending from these addresses. Grayscale notes that the bitcoin community has historically been divided on protocol changes, pointing to the recent debate over image data storage in blocks. In contrast, Ethereum faces distinct challenges, with Google's paper identifying multiple attack vectors worth over $100 billion and the Ethereum Foundation taking steps such as staking significant amounts of ether into validators, although it has not publicly disclosed its quantum migration timeline.