<xs:element name="hashName" minOccurs="0"> <xs:complexType> <xs:simpleContent> <xs:extension base="xs:string"> <xs:attribute name="algorithm" type="xs:string" use="required" /> <xs:attribute name="timestamp" type="xs:integer" use="required" /> </xs:extension> </xs:simpleContent> </xs:complexType> </xs:element>