Patent ID: 8108669
Filing Date: 2012-01-31
Classification: H04L

Abstract:
1. An image forming apparatus for attaching an electronic signature to image data read from a paper document, comprising a processing unit and a non-transitory storage medium tangibly embodying instructions executable by the processing unit to configure the processing unit to operate as: a first generating unit that generates a first electronic signature for the image data by using a first signature key certified by a first public key certificate; and a determining unit that that determines validity of the first public key certificate; a receiving unit that receives input of a second signature key and a second public key certificate, which are different from the first signature key and the first public key certificate, the second signature key being certified by the second public key certificate, in response to an event that the determining unit determines that the first public key certificate is invalid, wherein the determining unit determines validity of the second public key certificate, and the first generating unit generates a second electronic signature for the image data by using the second signature key, in response to an event that the determining unit determines that the second public key certificate is valid; and a second generating unit that generates a third electronic signature for the image data to be saved in a non-transitory predetermined recording medium, wherein in response to an event that the determining unit determines that the first public key certificate is invalid, (i) the first generating unit is prevented from generating the first electronic signature, (ii) the image data is saved in the predetermined recording medium and (iii) a user is provided with an option to sign later.