Bitcoin Developers Propose Reactive Plan to Counter Quantum Threats

A new approach is being considered by Bitcoin developers to address the potential threat of quantum computing to the network's security. Instead of imposing a pre-emptive freeze on vulnerable coins, the proposal involves a 'wait and react' strategy. This plan, put forth by BitMEX Research, involves placing a small amount of bitcoin in a special address that can only be accessed by a quantum-capable attacker. If the attacker unlocks the address, it would serve as proof that the threat is real and trigger a network-wide freeze of older wallets. The proposal also includes a bounty system to incentivize the first entity to demonstrate a quantum attack, rather than carrying out a stealthy theft. However, this approach relies on the assumption that the attacker will claim the bounty rather than maximizing their profit through theft. Bitcoin's security currently relies on digital signature schemes that are vulnerable to quantum computing, with some estimates suggesting a potential risk window by the end of the decade. The proposed 'canary' system is designed as an alternative to a fixed five-year timeline for imposing restrictions on vulnerable addresses. Critics of the fixed timeline approach argue that it undermines Bitcoin's core principle of private key control and could lead to the permanent freezing of unmigrated coins. The new proposal aims to balance the need for security with the need to preserve user control and flexibility. A 'safety window' is also introduced, which would make it harder for attackers to carry out stealthy attacks by restricting the ability to spend vulnerable coins for an extended period. However, the success of this plan hinges on the assumption that the first entity capable of breaking Bitcoin's security will choose to claim the bounty rather than carry out a large-scale theft. This assumption goes against the network's historical emphasis on preventing worst-case scenarios, and the potential consequences of failure could be severe.