Bitcoin Developers Propose 'Wait and React' Plan to Counter Quantum Threats

Bitcoin developers are considering a novel approach to mitigate the risks posed by quantum computing: instead of imposing a pre-emptive freeze on vulnerable coins, they would wait for an attacker to demonstrate their capabilities and then react. This 'wait and react' strategy relies on a 'canary' system, where a small amount of bitcoin is placed in a special address that can only be unlocked by a quantum-capable attacker. If the attacker unlocks the address, it would serve as public proof that the threat is real, triggering a network-wide freeze of older wallets. The proposal also includes a bounty system, where users can contribute bitcoin to incentivize the first entity to demonstrate a quantum attack, rather than attempting to exploit vulnerable wallets. However, this approach assumes that the attacker will prioritize claiming the bounty over maximizing their profits through theft. Bitcoin's digital signature schemes are currently secure against classical computers but may be vulnerable to advances in quantum computing, with some estimates suggesting a potential risk window by the end of the decade. The 'wait and react' strategy is designed as an alternative to a fixed five-year timeline, which has been criticized for being 'authoritarian and confiscatory.' The proposal also introduces a 'safety window' to make stealth attacks more difficult, where vulnerable coins can still be moved, but the recipient would be unable to spend them for an extended period. While this approach reduces the risk of disrupting users prematurely, it relies on the assumption that the first entity capable of breaking Bitcoin would claim the bounty rather than executing a large-scale theft. This assumption goes against Bitcoin's design principles, which prioritize security and resistance to protocol-level interventions. If the assumption proves incorrect, Bitcoin may face the worst of both worlds: the catastrophe it was trying to prevent, and the realization that a fixed-timeline defense would have been more effective.