Bitcoin Developers Propose 'Wait and React' Strategy to Counter Quantum Computing Threats

The Bitcoin community is considering a novel approach to addressing the potential threat of quantum computing to the network's security. Instead of implementing a pre-scheduled freeze on vulnerable coins, the proposed 'canary' system would only trigger a network-wide restriction if a quantum-capable attacker proves their capability by unlocking a special address. This approach is based on the assumption that the attacker will claim a bounty rather than maximizing their profit through theft. The system works by placing a small amount of bitcoin in a special address that can only be unlocked by a quantum-capable attacker, with any spend from that address serving as public proof that the threat has arrived, automatically triggering a network-wide freeze of older wallets. This proposal is designed as an alternative to the controversial BIP-361, which would impose restrictions on a fixed five-year timeline regardless of whether quantum computers are actually capable of attacking Bitcoin's blockchain. Critics have argued that BIP-361's approach is 'authoritarian and confiscatory,' undermining Bitcoin's core principle that control rests solely with private key holders. The proposed 'canary' system includes a financial incentive, allowing users to contribute bitcoin to the address and create a bounty that rewards the first entity to demonstrate a quantum attack publicly. The proposal also introduces a 'safety window' designed to make stealth attacks harder, where vulnerable coins could still move, but the recipient would be unable to spend them for an extended period. However, this approach relies on the assumption that the first entity capable of breaking Bitcoin would claim the bounty rather than execute a large-scale theft, which cuts against the network's design principles and historical resistance to protocol-level interventions.