To verify a card created with Microsoft Biometric ID Technology, the card is fed through a business card scanner connected to a PC with the Microsoft Biometric ID Technology verification software installed. The software accomplishes the following:
From the text hash (computed in Step 2) and the original signed message (computed in Step 3), the software extracts the compressed facial features and compares this with the facial features extracted from the portrait photo on the card to verify that the two are similar within the maximum tolerable compression-print-scan noise. If they are similar the card validation succeeds; otherwise the card is deemed to have been modified, which will result in a validation failure.
ID Verification (iris as biometric example)