Private Key Sharing (Blockchain) – Bitcoin Stack Exchange

Depending on the client you use, this may be a very bad idea. This is because some clients send changes to the new address, while others send changes back to the sending address.

If you use an online wallet like Blockchain.info, that’s okay, as the changes will be sent back on their own. In this case, both parties are online, so the customer always has an up-to-date list of transactions for that address. .

The chances of a conflict (aka: double spending) occurring are very low. This is because two people need to spend the same transaction within seconds of each other, and if they are both using the same online wallet, they will most likely need to do it at about the same time.

Your private key completely controls the ownership of your coins (and is therefore private), so you must completely trust anyone who knows about it.