Cryptographic processing method for protecting chip card against side channel attacks, involves determining arithmetic operation between correction data and result of Boolean function application to masked data to deliver second masked data

摘要

The method involves obtaining (106) first arithmetically masked data (A) corresponding to result of an arithmetic operation between first data and a first mask (M). Result of an application of a Boolean function to the masked data is determined. Correction data (H) and a second mask (M1) are determined. An arithmetic operation between the correction data and the result is determined to deliver second arithmetically masked data (A1) corresponding to a result of arithmetic operation between the second mask and a result of an application of the Boolean function to the first data. Independent claims are also included for the following: (1) a computer program product comprising a set of program code instructions for implementing a cryptographic processing method (2) a non-transitory computer readable storage medium for storing a computer program comprising a set of instructions executed by a computer or a processor to implement a cryptographic processing method (3) a cryptographic processing device.