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

The Bitcoin community is considering a novel approach to mitigating the risks associated with quantum computing, which could potentially compromise the security of the network. Instead of imposing a pre-emptive freeze on vulnerable coins, the proposed 'wait and react' strategy relies on a canary system that would trigger a network-wide restriction only if a quantum-capable attacker demonstrates their capabilities on-chain. This approach is designed to balance the need to protect the network with the risk of prematurely disrupting users. The canary system works by 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, automatically triggering a network-wide freeze of older wallets. This strategy is an alternative to the controversial BIP-361 proposal, which would impose a fixed five-year timeline for phasing out vulnerable addresses, regardless of whether quantum computers are actually capable of attacking the blockchain. The proposed canary system also introduces a financial incentive, allowing users to contribute bitcoin to the address and create a bounty that rewards the first entity to demonstrate a quantum attack publicly. However, this approach rests on the assumption that the first entity capable of breaking Bitcoin would claim the bounty rather than executing a large-scale theft, which raises concerns about the potential risks and consequences of such a strategy.