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

The Bitcoin community is considering a novel approach to address 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 trigger a network-wide restriction only if a quantum-capable attacker demonstrates their capabilities on-chain. This approach is based on a 'wait and react' strategy, which assumes that the first entity to demonstrate a quantum attack would claim a bounty rather than attempting to steal funds. 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 a fixed five-year timeline for implementing security measures, which has been criticized for being 'authoritarian and confiscatory.' The new approach includes a financial incentive, allowing users to contribute to a bounty that rewards the first entity to demonstrate a quantum attack. The proposal also 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, this approach relies on the assumption that the first entity capable of breaking Bitcoin's security would claim the bounty rather than attempting to steal funds, which may not be a reliable bet. If this bet fails, 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 stopped it.