# File lib/openid/dh.rb, line 39
    def xor_secrect(composite, secret)
      dh_shared = get_shared_secret(composite)
      sha1_dh_shared = OpenID::Util.sha1( \
                          OpenID::Util.num_to_str(dh_shared))
      return OpenID::Util.strxor(secret, sha1_dh_shared)
    end