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

A recent proposal by BitMEX Research has sparked debate among Bitcoin developers, who are considering a novel approach to addressing the potential threat of quantum computing to the network. Instead of imposing a pre-scheduled freeze on vulnerable coins, the proposal suggests a 'wait and react' strategy, which would only trigger a network-wide restriction if a quantum-capable attacker demonstrates their capability on-chain. This approach is designed to reduce the risk of disrupting users prematurely, but it relies on the assumption that the first entity capable of breaking Bitcoin's security would claim a bounty rather than executing a large-scale theft. The proposal outlines a 'canary' system, where a small amount of bitcoin is placed in a special address that only a quantum-capable attacker could unlock, triggering a network-wide freeze of older wallets if the address is accessed. This approach is seen as an alternative to BIP-361, a controversial proposal that would impose a fixed five-year timeline for phasing out vulnerable addresses, regardless of whether quantum computers are actually capable of attacking the blockchain. Critics of BIP-361 have argued that it undermines Bitcoin's core principle of control resting with private key holders, and could result in the permanent freezing of unmigrated coins. The new proposal introduces a financial incentive, allowing users to contribute to a bounty that rewards the first entity to demonstrate a quantum attack publicly, rather than quietly draining vulnerable wallets. The proposal also includes a 'safety window' designed to make stealth attacks more difficult, by introducing a delay between the movement of vulnerable coins and their ability to be spent. While this approach reduces the risk of premature disruption, it rests on the bet that the first entity capable of breaking Bitcoin's security would claim the bounty rather than executing a large-scale theft. This bet goes against the worst-case scenario that Bitcoin's design has always tried to prevent, and the network has historically shown little appetite for undoing such events after the fact.