In my opinion, the problem is this:
They should stop that. It is silly. Whatever convoluted workaround we come up with is going to be far worse than simply doing the right thing.
The right thing, by the way, is for the casino to request a return address (address A), then generate a new address (address B), and link them in a database so that earnings made with BTC deposited to address B will only be returned to address A.
4) Casino only sends withdrawals to depositing address.
They should stop that. It is silly. Whatever convoluted workaround we come up with is going to be far worse than simply doing the right thing.
The right thing, by the way, is for the casino to request a return address (address A), then generate a new address (address B), and link them in a database so that earnings made with BTC deposited to address B will only be returned to address A.
Yes, you should insist that customers give you a refund/cash-out address BEFORE you give them the funding address.