3.2.2 Hardware Countermeasures
The AES module features four types of hardware countermeasures that are useful for protecting data against differential power analysis attacks:
Type 1: Randomly add one cycle to data processing
Type 2: Randomly add one cycle to data processing (other version)
Type 3: Add a random number of clock cycles to data processing, subject to a maximum of 11/13/15 clock cycles for key sizes of 128/192/256 bits
Type 4: Add random spurious power consumption during data processing