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 imposing a pre-emptive freeze on vulnerable coins, the proposal involves a 'wait and react' strategy that relies on the first quantum-capable attacker to reveal their capabilities in exchange for a bounty. This approach is designed to avoid premature disruption to users and is based on the assumption that the attacker will prioritize claiming the bounty over exploiting the vulnerability for personal gain. The proposal outlines a system where a small amount of bitcoin is placed in a special address that can only be unlocked by a quantum-capable attacker, triggering a network-wide freeze of older wallets once the threat is demonstrated. This mechanism is intended to provide an alternative to the controversial BIP-361 proposal, which would impose a fixed five-year timeline for phasing out vulnerable addresses. Critics of BIP-361 argue that it undermines Bitcoin's core principle of private key holder control and could result in the permanent freezing of unmigrated coins. The new proposal introduces a financial incentive for users to contribute to the bounty, which rewards the first entity to demonstrate a quantum attack publicly. Additionally, a 'safety window' is designed to make stealth attacks more difficult by restricting the ability to spend vulnerable coins for an extended period. While this approach reduces the risk of disrupting users prematurely, it relies on the assumption that the first quantum-capable attacker will prioritize claiming the bounty over executing a potentially catastrophic theft. This assumption is at odds with Bitcoin's historical emphasis on preventing worst-case scenarios, and the network's resistance to protocol-level interventions to undo such events. 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 been more effective.