Patent ID: 8488136

Claim:
A printing system comprising: a client for sending file data, described in Portable Document Format (PDF); and a printer for directly printing the file data described in the PDF, sent from the client, wherein the client includes: additional pattern generating means for generating an additional pattern; print layout selecting means for selecting a print layout; client side decoding means for determining whether a PDF file under processing is encrypted, decoding the PDF file under processing encrypted with a first encryption key when the additional pattern is appended to the PDF file, and refraining from decoding the PDF file under processing encrypted with the first encryption key when the additional pattern is not appended to the PDF file; PDF file re-making means for analyzing the PDF file under processing decoded by the client side decoding means when the additional pattern is appended to the PDF file, and appending the additional pattern, generated by the additional pattern generating means, to the PDF file decoded by the client side decoding means consistent with the print layout selected by the print layout selecting means; encrypting means for encrypting, with a second encryption key different from the first encryption key, the PDF file with the additional pattern that has been re-made by the PDF file re-making means consistent with the print layout selected by the print layout selection means; and PDF file send-out means for appending to the encrypted PDF file including the additional pattern a decoding key for decoding the PDF file including the additional pattern encrypted by the encrypting means when the additional pattern has been appended to the PDF file, according to a preset rule established between the client and the printer that decodes the PDF file inclusive of the additional data encrypted by the encrypting means to print file data described by PDF, and for sending a result of the appendage to the printer, or for sending the encrypted PDF file to the printer without decoding the encrypted PDF file when the additional pattern is not appended to the PDF file, the printer includes: printer side decoding means for decoding, with the decoding key, the encrypted PDF file including the additional pattern sent from the client; and printing means for directly printing, in the print layout selected by the print layout selecting means, the file data described in PDF in the PDF file including the additional pattern decoded by the printer side decoding means, along with the additional pattern.