Say you have a multi-sig tx that originated from a 2-of-3 P2SH address.
Is it possible to say who signed the transaction? i.e. you can get access to the redeem script once the tx is broadcasted, and thus you have access to all 3 public keys that generated the 2-of-3 P2SH address. Arguably you can identify which public keys signed the transaction?
If yes, then how?