Patent ID: 7734599
Filing Date: 2010-06-08
Classification: G06F,H04L

Abstract:
1. An image processing apparatus for performing printing based on print data received from an information processing apparatus, the image processing apparatus comprising: a print data receiving unit at a network printing side configured to receive a plurality of data blocks of the print data which are separately transmitted from the information processing apparatus on a client side, the plurality of data blocks of the print data originating from a print job; and a processor configured to generate a hash value from each of the data blocks of the print data received by the print data receiving unit, extract header information from a predetermined data block following the data block of the received print data from which the hash value is generated, determine whether the extracted header information coincides with the generated hash value, and cause the image processing apparatus to perform printing based on a determination of whether the extracted header information coincides with the generated hash value, wherein an electronic signature is added to a first data block of the plurality of data blocks received by the print data receiving unit, and the processor inhibits the image processing apparatus from performing the printing in a case where the processor verifies that the electronic signature is not correct, and wherein the data block is formed by adding a hash value from a data piece of a preceding data block to following data block, the data block includes the data piece and the header information indicating the hash value, and the hash value indicated by the header information included in the data block for a data block subsequent to the first block is generated from a data piece included in the preceding data block.