Grayscale, a prominent digital asset management firm, has released a research note advocating for accelerated efforts to enhance public blockchains' resistance to quantum computing threats. The note emphasizes that although the necessary technical solutions are already available, garnering consensus within decentralized communities to implement these solutions poses a significant obstacle. This comes on the heels of a recent paper by Google Quantum AI, which revealed that compromising bitcoin's elliptic curve cryptography could be achieved with fewer than 500,000 physical qubits, significantly lowering the threshold from previous estimates. The study found that such an attack could be executed in approximately nine minutes, giving the attacker a roughly 41% chance of stealing funds before a transaction is confirmed.
Grayscale's analysis highlighted four key takeaways from Google's research, including the unpredictable timeline for developing a cryptographically relevant quantum computer and the maturity of post-quantum cryptography in securing internet traffic and certain blockchain transactions. The firm noted that bitcoin's quantum risk is relatively lower due to its UTXO model, proof-of-work consensus, and lack of native smart contracts. However, the firm raises concerns about the approximately 6.9 million BTC in wallets with exposed public keys, including an estimated 1 million coins believed to belong to Satoshi Nakamoto.
Possible solutions include burning these coins, taking no action, or limiting their spending rate. The bitcoin community's history of contentious debates over protocol changes may hinder the implementation of such solutions.
In contrast, Ethereum faces distinct challenges, with five identified attack vectors worth over $100 billion in combined exposure. The Ethereum Foundation has been actively staking ether into validators but has not publicly disclosed its quantum migration timeline.