US 12,438,712 B2
Encryption processing apparatus, encryption processing method for encryption processing apparatus, and storage medium
Yoshihiko Shimokawa, Kanagawa (JP); and Akiyoshi Momoi, Kanagawa (JP)
Assigned to Canon Kabushiki Kaisha, Tokyo (JP)
Filed by CANON KABUSHIKI KAISHA, Tokyo (JP)
Filed on Sep. 29, 2023, as Appl. No. 18/478,819.
Claims priority of application No. 2022-159284 (JP), filed on Oct. 3, 2022.
Prior Publication US 2024/0113871 A1, Apr. 4, 2024
Int. Cl. H04L 9/08 (2006.01); H04L 9/06 (2006.01)
CPC H04L 9/0869 (2013.01) [H04L 9/0618 (2013.01)] 14 Claims
OG exemplary drawing
 
1. An encryption processing apparatus comprising:
a random number generation unit configured to generate a random number;
a table generation unit configured to generate a masked non-linear transformation table using the random number as a mask value;
a storage unit configured to store the mask value and the masked non-linear transformation table;
a first selection unit configured to select, from among the mask value and the masked non-linear transformation table that are stored in the storage unit, one set of a mask value and a masked non-linear transformation table that are to be rewritten;
an operation unit configured to perform an operation using the mask value and the masked non-linear transformation table; and
a second selection unit configured to select, from among the mask value and the masked non-linear transformation table that are stored in the storage unit, the mask value and the masked non-linear transformation table that are to be used by the operation unit,
wherein the storage unit stores one or more mask values in addition to a number of the mask values to be used by the operation unit and stores one or more masked non-linear transformation tables in addition to a number of masked non-linear transformation tables to be used by the operation unit,
wherein the mask value and the masked non-linear transformation table that the first selection unit selects and the mask value and the masked non-linear transformation table that the second selection unit selects are different from each other,
wherein the generation of the masked non-linear transformation table by the table generation unit and the operation by the operation unit are processed concurrently, and
wherein, after completion of the rewriting of the storage unit, the first selection unit and the second selection unit select the mask value and the masked non-linear transformation table that are different from the rewritten mask value and the rewritten masked non-linear transformation table.