Corey Fields has proposed a draft of an idea in which he contemplates creating a mechanism that penalizes any attempt to steal funds using a quantum computer by paying a reward to whoever proves it. He proposes enabling new validation rules on Q-day. He suggests using a trap mechanism that can be set in advance to prevent a quantum thief. This involves transactions with hidden proof of ownership, which is revealed when a thief attempts to steal the coins. This would result in the thief losing their funds, making it clear that the owner of the trap is even interested in the thief being caught this way. The thief cannot detect the trap in advance, since before it is triggered, the trap appears to be a normal, small, secure UTXO.
https://groups.google.com/g/bitcoindev/c/ARMwWdWcz9A?pli=1
