Patent ID: 7984305

Claim:
An encryption processing apparatus configured to perform a data encryption process, said encryption processing apparatus comprising: a processor configured to provide: a control section configured to set a mixed encryption processing sequence by dividing an original encryption processing sequence into a plurality of groups, each group being composed of a plurality of encryption processing units, each encryption processing unit being a defined process, each group being a separate and independent encryption process for encrypting an input data, where a first input data to be encrypted for a first group of the groups is different relative to a second input data to be encrypted for a second group of the groups, and the first input data to be encrypted for the first group is generated independently relative to the second input data to be encrypted for the second group, said control section mixing processing sequences of encryption processing units of the plurality of groups with each other by executing performance of at least one encryption processing unit from the first group at a time between executing performance of encryption processing units from the second group and under a condition in which a processing sequence of the encryption processing units within each of the plurality of groups is fixed; an encryption processing section configured to perform an encryption process in accordance with the mixed encryption processing sequence set by said control section; and a transmitting unit configured to transmit each of encrypted output data generated independently by the first group and the second group to an external device, wherein each group includes a triple-DES encryption process and said control section is configured to set a dummy single-DES process as a dummy encryption process that is unnecessary for an encryption processing sequence in at least one of said groups, and set the number of dummy single-DES processes to be a multiple of 3, and said control section is configured to set a dummy encryption processing unit that performs the dummy encryption process in at least one of the groups, and set one mixed encryption processing sequence by mixing the encryption processing units of a plurality of groups containing the dummy encryption processing unit.