You don’t want to know every certificates individually in an effort to verify them. This property comes from what is named the “chain of belief” when coping with certificates.
Every Developer Certificates has been signed by Apple utilizing their key. An app signed with a Developer Certificates consists of not solely the title of the customized developer, but additionally the chain of belief, in order that it’s evident whether or not or not Apple has signed that Developer Certificates.
Thus you solely have to know Apple’s certificates in an effort to validate whether or not an app has been signed by a key that Apple has accredited.