The present invention provides methods and systems for authenticating identification documents (100). We also teach an identification document (100) including two or more digital watermarks (27, 60). The watermarks correspond with each other or with indicia carried by the identification document (100). The correspondence can be verified to determine authenticity. We also provide digital watermark detection methods and systems to identify the different watermarks (100) through embedded orientation components. We then focus watermark message-decoding efforts on areas identified as likely including watermark orientation components (27, 60). In one implementation we provide a watermark detection trigger to identify so-called legacy documents. The trigger may indicate the presence or expected absence of a digital watermark. In other implementations we provide a versatile document authenticator to toggle between watermarking and non-watermarking authentication processes depending on a detection trigger (100).