US 11,991,334 B2
Image forming apparatus, control method, and storage medium
Shiro Kunori, Kanagawa (JP)
Assigned to Canon Kabushiki Kaisha, Tokyo (JP)
Filed by CANON KABUSHIKI KAISHA, Tokyo (JP)
Filed on Oct. 21, 2021, as Appl. No. 17/507,308.
Claims priority of application No. 2020-187610 (JP), filed on Nov. 10, 2020.
Prior Publication US 2022/0150377 A1, May 12, 2022
Int. Cl. B41M 3/14 (2006.01); H04L 9/32 (2006.01); H04N 1/32 (2006.01); H04L 9/00 (2022.01)
CPC H04N 1/32144 (2013.01) [B41M 3/14 (2013.01); H04L 9/3236 (2013.01); H04L 9/50 (2022.05)] 10 Claims
OG exemplary drawing
 
1. An image forming apparatus that cooperates with a management service which receives a document via a network and stores the document and a blockchain service which manages information about the document on a block-by-block basis and, upon defining association of each block with a previous and/or subsequent block, manages a plurality of blocks with a plurality of nodes, the image forming apparatus comprising:
a generation unit configured to, in printing a document stored in the management service, generate one or more embedded images based on existence proof information for confirming that information about a printed product of the document exists in the blockchain service and tampering detection information for confirming that there is no tampering in a printed product obtained by printing the document;
a registration unit configured to register the existence proof information and the tampering detection information with the blockchain service;
a printing unit configured to perform printing of the document with the one or more embedded images embedded therein; and
a control unit configured to, when verifying a printed product obtained by the printing unit, perform two verifications indicating that information about the printed product exists in the blockchain service and that there is no tampering in the printed product, by decoding the one or more embedded images included in the printed product to acquire the existence proof information and the tampering detection information and making an inquiry about the existence proof information and the tampering detection information registered in blocks of the blockchain service.