Bitcoin Core developer Cory Fields has proposed the concept of “Quantum Landmines” to deter the theft of bitcoin using future quantum computers.
Under Fields’ concept, anyone attempting to use a quantum computer to calculate the private key of a vulnerable wallet and move its BTC would have to place an additional amount of BTC equal to the amount being moved as collateral. For example, moving 1 BTC would require depositing an additional 1 BTC, with both assets locked for about 30 days.
If the original owner had prepared a secret proof of ownership in advance, before quantum computers became a threat, they could disclose it during the waiting period and claim both the original BTC and the collateral deposited by the other party. Attackers would not know in advance which wallets had such a mechanism prepared.
Fields, however, explicitly described the idea as a “thought experiment,” rather than a proposal for actual implementation. For the mechanism to work, quantum-resistant wallets and new verification rules would first have to be introduced to Bitcoin. A limitation is that legitimate owners of existing wallets could also be required to provide the same collateral when moving their assets.