Suppose there were 3 people, Alice, Bob, and Carl. Alice has a multisig wallet with Bob and another with Carl. Bob signs a transaction and sends it to Alice to get the second signature.
Is there a way to set this up such that alice does not know whether she's signing a transaction from the multisig wallet with Bob or the multisig wallet with Carl?
Obviously, this means that Alice can't know the balance of either multisig wallet, or she could check the pre and post balance. And also her key for both multisig wallets would have to be the same, or she'd know based on which signature she needed to sign. Other than these two properties, I can't think of any way Alice would know.
Is this a possible set up?
Related reading:
How to Use Monero Multisignature Wallets (2/2 & 2/3)
This QA makes it clear the current CLI definitely makes it possible for both alice and bob to see the balance, whereas I only want bob. But is that just the way this command works or is that fundamental to the nature of multisigs?
Does Multisig have any privacy drawbacks?
The fact that all the multisig magic happens off chain, as said in the above post, makes me think at least the second property (using the same key in two different multisigs) should work, but I don't know about the first (being able to sign a transaction without knowing the balance).
To be clear, bob and carl should be able to view the balance of their respective wallets, and I don't mind if alice knows the amount of the transaction, just not the amount in the wallet.
