88
SubjectConfirmation Method Identifiers
urn:oasis:names:tc:SAML:2.0:cm:holder-of-key
The
presenter (of the assertion) must hold a key to prove that he is the subject.
urn:oasis:names:tc:SAML:2.0:cm:bearer
The
presenter (bearer of the assertion) is assumed to be the subject.
urn:oasis:names:tc:SAML:2.0:cm:sender-vouches
The
presenter is being vouched for by the sender.