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

The Bitcoin community is considering a novel approach to mitigate the potential risks posed by quantum computing, focusing on a 'wait and react' strategy rather than imposing a pre-emptive freeze on vulnerable coins. This approach, outlined in a proposal by BitMEX Research, involves creating a 'canary' system that would trigger a network-wide restriction on older bitcoin wallets only if a quantum-capable attacker demonstrates their capabilities on-chain. The system would work by placing a small amount of bitcoin into 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 materialized, thereby triggering a network-wide freeze of older wallets. This proposal is designed as an alternative to BIP-361, which 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 control resting solely with private key holders. The 'canary' system also introduces a financial incentive, where users can contribute bitcoin to the address, creating a bounty that rewards the first entity to demonstrate a quantum attack publicly. However, 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 kind of worst-case scenario Bitcoin's design has always tried to prevent.