Credential

An object or data structure that authoritatively binds an identity (and optionally, additional attributes) to a token possessed and controlled by a Subscriber. SOURCE: SP 800-63

Evidence attesting to one’s right to credit or authority.
SOURCE: FIPS 201

Evidence or testimonials that support a claim of identity or assertion of an attribute and usually are intended to be used more than once.
SOURCE: CNSSI-4009