Well it’s pretty simple, for bitkey 2/3 keys are controlled by the entity that controls the money. It is very simply self-custody.

For fedimints, it’s 4 third parties that you need to trust to custody your money. I don’t know how those 4 parties also enter into a federation without explicit trust between them. In a federation you need to confirm:

- whether those third parties are actually different people

- whether those different people actually hold the keys they say they do

- what the relationship between them is

Their relation being the really key part. Is it 3 people from the same company? I don’t know how you enter a federation without explicit trust and some sort of relation with other guardians. This is usually done formally with contracts.