But wait a moment!
Why would someone go take loan from bank and want to present their digital currency to Bank?
Well, I see no sense of having Bitcoin and you want to hold it back and borrow money, why not just convert few sat and do your things thank having to go through stress to loan money in the bank, besides Nigeria bank like I know can never accept Bitcoin as a collateral for someone to borrow money from bank after knowing how volatile the crypto currency market be. Do you also realize that any amount you are loan from bank are generally people funds that was stored in the bank, when the needs arises they go make use of the money than just giving out huge some of money and expect bank to have a volatile asset as their collateral this won't be possible.