Bitcoin Core developer proposes collateral defense scheme against quantum attacks

Bitcoin Core developer Cory Fields has proposed a "quantum mine" mechanism that would require anyone moving quantum-vulnerable bitcoin to post additional collateral and wait through a delay period, raising the cost for a future quantum attacker to steal coins from old wallets. Legitimate holders could reclaim their assets and the attacker's collateral by presenting a pre-committed secret proof of ownership within that window, though honest holders moving such coins would also have to post collateral since the blockchain cannot distinguish them from attackers. For dormant coins whose private keys are already lost, Fields suggested a challengeable auction mechanism. The proposal remains a draft and is not yet an implemented network rule. It matters because a cryptographically relevant quantum computer could eventually let attackers derive private keys from exposed public keys and sweep vulnerable addresses, and the debate now shifts to how the proposal might be refined and whether it gains traction among node operators and wallet providers.