Patent ID: 8767956

Claim:
A system, comprising: a memory unit that stores key data for a cryptographic processing; and circuitry configured to perform an encryption of the cryptographic processing or a decryption of the cryptographic processing; transform first input information into first nonlinear transformed information, and to transform the first nonlinear transformed information into first linear transformed information; transform second input information into second nonlinear transformed information, and to transform the second nonlinear transformed information into second linear transformed information; and perform an exclusive-or operation based on the second linear transformed information and the first linear transformed information, wherein, when the first nonlinear transformed information is expressed as a first sequence vector, the first linear transformed information is expressed as a second sequence vector, the second nonlinear transformed information is expressed as a third sequence vector, and the second linear transformed information is expressed as a fourth sequence vector, then a first row vector chosen from a first inverse matrix of a first matrix that transforms the first sequence vector to the second sequence vector, and a second row vector chosen from a second inverse matrix of a second matrix that transforms the third sequence vector to the fourth sequence vector, are linearly independent.