A system includes a firewall, a first server located behind the firewall, and a second server located before the firewall. The second server is configured to receive a request for data, select an item code from a code database corresponding to the requested data, and transmit the item code to the first server, wherein the item code comprises a coded number representing an item in a secure database. The first server is configured to receive the item code from the second server and, if the item code corresponds to one of a plurality of codes of a code database maintained by the first server, send the data to the second server.