Distinguishing bitcoin deposits If i had a central Bitcoin wallet, and then allowed 3 different people to deposit bitcoin into that address, would there be anyway to distinguish who they are, without knowing who's address is who, i know sending messages with transactions isn't supported by all wallets so i was just wondering if there was a different way.
Like i said i've tried passing a message through the transaction but that isn't always possible from the wallets.
Maybe theres another way to check someone is the owner of a wallet. Other than signing a message of course.
Generally speaking, the only way to distinguish incoming payments is by some combination of

sending address (usually arbitrary and not always known in advance)
amount (could be same for many people if you are selling fixed-price widgets)
receiving address (no good if you give everyone the same address to send money to)

That is one reason why best practice is to generate a new receiving address per transaction.