Document title: SAML Authentication Context Extension Schema for Text Based Challenge Response Tokens Document identifier: sstc-saml-ac-ext-tcr.xsd Location: http://www.oasis-open.org/committees/documents.php?wg_abbrev=security Revision history: V2.0 (Sept 2006): This element can only appear as an Extension in PrincipalAuthenticationMechanismType Identifies the type of token and authentication A URI pointing to descriptive information about the type of text-based challenge response scheme supported by the token The total number of possible challenges represented on the token The total number of possible values for each response The number of challenges used in an authentication operation An indication of whether the token identity (eg serial number) was checked