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: instead of proactively freezing vulnerable coins, the network would only take action if an attacker proves the threat is real. However, this plan relies on the assumption that the attacker will choose to reveal their capabilities in exchange for a bounty rather than exploiting the vulnerability for personal gain. This 'wait and react' strategy, proposed by BitMEX Research, involves placing a small amount of bitcoin in a special address that can only be accessed by a quantum-capable attacker. If the attacker spends from this address, it would serve as public proof that the threat has materialized, triggering a network-wide freeze of older wallets. The proposal aims to provide an alternative to the controversial BIP-361, which suggests imposing restrictions on a fixed five-year timeline regardless of whether quantum computers can actually attack Bitcoin's blockchain. Critics argue that BIP-361's approach is overly authoritarian and could result in the confiscation of coins, undermining Bitcoin's core principle of private key ownership. The BitMEX proposal incorporates a financial incentive, allowing users to contribute to a bounty that rewards the first entity to demonstrate a quantum attack publicly. This bounty is designed to encourage attackers to reveal their capabilities rather than exploiting vulnerable wallets quietly. Additionally, the proposal introduces a 'safety window' that makes stealth attacks more difficult by restricting the ability to spend coins for an extended period. If the 'canary' is triggered during this window, the coins would be frozen retroactively, increasing the risk for any attacker attempting to quietly extract funds. However, this approach rests on the uncertain assumption that the first entity capable of breaking Bitcoin would choose to claim the bounty rather than executing a potentially massive theft. This bet goes against Bitcoin's design principles, which have always aimed to prevent worst-case scenarios. If the 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 could have stopped it.