The on-line and off-line issuing of documents and authentication system using watermarking techniques and method thereof

摘要

PURPOSE: A system for issuing and certifying a document using a watermarking and a certification method thereof are provided to issue a certificate on online or offline by inserting a watermark into the certificate, and to make an organization or a company requesting the certificate certify the integrity and the justice of the certificate by the extraction of the watermark. CONSTITUTION: A user system(20) comprises a PC(21) being equipped with a watermark inserting program, requesting the document and receiving a certificate document file inserted by the watermark, and a printer(22) outputting a certificate document(30) by receiving the certificate document file. A document issuing system(10) comprises a document issuing server(16) issuing the certificate document file by using the digital information and the watermark information and transmitting it to the requestor's PC, a document information database(14) of each document issuing organization providing the digital information of the certificate document, and a watermark database(12). A certification system(40) includes a scanner for extracting the watermark and the original code information, and a watermark extracting program.