Can the signers of a 2 of 3 multisig tx be identified later For accountability reasons:

If public keys of each signer is known, can the 2 out of 3 parties be identified later, or just that it was some combination of the 3 parties? 

If the 2 parties can not be identified, how should this be done if its necessary?
When spending a multisig output, the signatures and redeem script are public information.

This allows you to identify:


The number of potential signers
The number of required signatures
Public keys for all potential signers
Which keys signed the transaction (from the signature).


It will not reveal the identity of who owns a public key, unless you have some offchain analysis to go with this data, and already know who owns which public key.