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

Bitcoin developers are considering a novel approach to addressing the potential threat of quantum computing to the network's security. Instead of imposing a pre-scheduled freeze on vulnerable coins, the proposed 'canary' system would trigger a network-wide response only if a quantum-capable attacker demonstrates their capabilities on-chain. This approach is based on a 'wait and react' strategy, which relies on the assumption that the attacker will claim a bounty rather than exploiting the vulnerability for personal gain. The system involves 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. The proposal is designed to provide an alternative to BIP-361, a controversial plan that would impose restrictions on a fixed five-year timeline, regardless of whether quantum computers are actually capable of attacking Bitcoin's blockchain. Critics of BIP-361 argue that it undermines Bitcoin's core principle of private key holder control. The 'canary' system also includes a financial incentive, allowing users to contribute bitcoin to a bounty that rewards the first entity to demonstrate a quantum attack publicly. Additionally, the proposal introduces a 'safety window' to make stealth attacks more difficult, during which vulnerable coins could still be moved, but the recipient would be unable to spend them for an extended period. However, the success of this approach relies on the assumption that the first entity capable of breaking Bitcoin would claim the bounty rather than executing a large-scale theft, which is a bet that cuts against the network's design principles and historical responses to security threats.