Self validating security documents utilizing watermarks

摘要

Security documents which has multiple fields or areas each of which contains information that is perceptible in more than one way: One field can contain a visually perceptible image and a digital watermark that can be detected when the image is scanned and processed, and another field can contain watermark data which can be correlated to the output of a fingerprint reader or of apparatus which scans a user's iris. The watermarks in the different graphic elements of the document are correlated to each other and correlated to the visual material on the document. Thus, the document can not be forged by replacing one element (such as a picture) with a similar element from another document. An automatic validation system of the present invention reads multiple fields on the document, and it also automatically detects information about the user. The various information is correlated to validate the document.