Patent ID: 8345313

Claim:
An image forming apparatus that produces a print product constituted by at least one page, based on print data representing a plurality of print objects which are to be included within the at least one page, comprising: printing section to conduct a printing operation; digital signature analyzing section to analyze a digital signature attached to a print object to determine whether the digital signature is valid or invalid; and control section to control the printing section based on the print data, wherein, in a case where (A) a plurality of digital signatures are respectively attached to the plurality of print objects which are to be included within the at least one page, and (B) the plurality of print objects which are to be included within the at least one page includes both of a valid print object for which the digital signature is valid and an invalid print object for which the digital signature is invalid, the control section enables an image formation for the valid print object based on the print data while disables an image formation for the invalid print object based on the print data.