Hi, I have a question for you pls. Does it means that a miner could hack the bitcoins from who really worked out the puzzles? Because once he signed the transaction, the miners knows the public key and if they know this is for the puzzles, they can utilize your method to find corresponding private key and hacked the funds.
For what all guys are saying here - seems like each and every random transaction should be possible to be stolen just knowing the public key. At any time when it is still in mempool.