Ha-ha :) You are not the first one :) It's a catch :) The sha-256/512 were defined in XML Enc spec (http://www.w3.org/TR/xmlenc-core/#sec-Alg-MessageDigest) thus the URIs are http://www.w3.org/2001/04/xmlenc#sha256 http://www.w3.org/2001/04/xmlenc#sha512 Aleksey