A system method for providing an authentication code across a network for use in authentication of documents, such as printed lottery tickets. The system includes document-printing terminals that create a first key and a second key, with the first key used to generate an authentication code for printing on the document, and the second key is sent to a central server and usable to verify that the first key created the authentication code. The central server can also provide ticket serial numbers for tickets being dispensed at the terminals and the first key can be combined with the serial number and other secondary data to create the authentication code.