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

The Bitcoin community is considering a novel approach to mitigating the risks associated with quantum computing, which could potentially compromise the security of the network. Instead of imposing a pre-scheduled freeze on vulnerable coins, the proposed 'canary' system would only trigger a network-wide restriction if a quantum-capable attacker demonstrates their capabilities on-chain. This 'wait and react' strategy is designed to balance the need for security with the risk of disrupting users unnecessarily. 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. This would automatically trigger a network-wide freeze of older wallets. To incentivize the first entity to demonstrate a quantum attack, users can contribute bitcoin to the address, creating a bounty that rewards the attacker for revealing their capabilities rather than exploiting them for personal gain. The proposal also includes a 'safety window' designed to make stealth attacks more difficult, by introducing a delay between the movement of vulnerable coins and the ability to spend them. While this approach reduces the risk of premature disruption, it relies on the assumption that the first entity capable of breaking Bitcoin's security would claim the bounty rather than execute a large-scale theft. This assumption has sparked debate, as it goes against the network's historical emphasis on preventing worst-case scenarios and minimizing protocol-level interventions.