Blockstream CEO Adam Back stated that Bitcoin should adopt an optional quantum-resistant upgrade scheme, rather than the mandatory freeze of quantum-threatened tokens proposed in BIP-361. BIP-361 proposes phasing out quantum-vulnerable addresses over five years and eventually freezing unmigrated tokens, including assets held by Satoshi Nakamoto. Recent research from Google indicates that a superconducting quantum bit system could potentially crack Bitcoin encryption in minutes with fewer than 500,000 physical qubits. Currently, approximately 6.9 million BTC are at this risk. In response to the quantum threat, BitMEX Research has proposed establishing a canary fund to implement a full freeze only when expenditures occur at relevant addresses.