Bitcoin Developers Propose Alternative Plan to Counter Quantum Computing Threats

The Bitcoin community is considering a novel approach to address the potential threat of quantum computing to the network's security. Instead of implementing a pre-scheduled freeze on vulnerable coins, the proposed 'canary' system would trigger a network-wide response only if a quantum-capable attacker demonstrates their capabilities on-chain. This approach is based on the assumption that the attacker would claim a bounty rather than exploiting the vulnerability for personal gain. The system involves placing a small amount of bitcoin in a special address that can only be unlocked by a quantum-capable attacker, which would serve as public proof of the threat and automatically trigger a network-wide freeze. The proposal is designed to provide an alternative to the controversial BIP-361, which would impose a fixed five-year timeline for phasing out vulnerable addresses and invalidating old signature schemes. Critics argue that BIP-361 could lead to an 'authoritarian and confiscatory' outcome, undermining Bitcoin's core principle of private key control. The new proposal includes a financial incentive, allowing users to contribute to a bounty that rewards the first entity to demonstrate a quantum attack publicly. The system also introduces a 'safety window' to make stealth attacks more difficult, allowing vulnerable coins to move but restricting the recipient's ability to spend them for an extended period. However, the proposal relies on the assumption that the first entity capable of breaking Bitcoin would claim the bounty rather than executing a large-scale theft, which may not be a reliable bet.