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

The Bitcoin community is considering a novel approach to addressing the potential threat of quantum computing to the network's security. Instead of imposing a pre-emptive freeze on vulnerable coins, the proposal involves waiting for a quantum-capable attacker to demonstrate their capabilities and then reacting accordingly. This 'wait and react' strategy is based on a 'canary' system, which would place a small amount of bitcoin in a special address that can only be unlocked by a quantum-capable attacker. If the attacker unlocks the address, it would serve as public proof that the threat is real and trigger a network-wide freeze of older wallets. The proposal also includes a financial incentive, where users can contribute to 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's security would prefer to claim the bounty rather than carry out a large-scale theft. This assumption has raised concerns, as it goes against the network's design principle of preparing for worst-case scenarios. The proposal is seen as an alternative to a previous plan, known as BIP-361, which would impose a fixed five-year timeline for phasing out vulnerable addresses and invalidating old signature schemes. Critics have argued that BIP-361's approach is overly restrictive and could lead to the permanent freezing of unmigrated coins, undermining Bitcoin's core principle of user control. The 'wait and react' strategy aims to balance the need to address potential quantum threats with the need to preserve user autonomy and flexibility.