1. A method for authenticating a certificate chain within a dispersed storage network (DSN), wherein the method comprises: receiving the certificate chain that includes one or more signed certificates; determining whether at least one of the one or more signed certificates has a valid signature; and when the at least one of the one or more signed certificates has a valid signature: identifying one or more certificate authorities (CA) from the one or more signed certificates to produce identified CAs; accessing registry information that includes one or more realm identifiers (IDs) and a plurality of trusted certificate authority (CA) IDs; determining whether one or more of the identified CAs is a trusted CA based on the registry information; when the one or more of the identified CAs is a trusted CA, indicating that the certificate chain is valid; identifying a realm ID of the one or more realm IDs based on a trusted CA ID of the one or more of the identified CAs that is a trusted CA, wherein the realm ID identifies a predetermined grouping of entities associated with the DSN; and generating certificate chain validation information to include the realm ID, the one or more of the identified CAs is the trusted CA, and the indication of the validity of the certificate chain.