APPARATUS AND METHODS TO HIDE POWER SIGNATURE IN CRYPTOGRAPHIC CIRCUITS

摘要

A cryptographic device (200) reduces risk of external analysis of power consumed by an encryption circuit (206) by maintaining a substantially current draw on an external power input node (Nl) during operation. An active shunt current regulator (208) draws current to ground when not drawn by the encryption circuit (206). A low-pass filter (202) and a linear voltage regulator (204) smoothes power spikes and keeps power supply voltage constant at an input to the encryption circuit (206).