Power analysis attacks are one of the biggest threat to embedded encryption chip during the last years,it can break password of the encryption chip protection with lower cost and higher speed.In this paper,the simple fixed-value masking is analyzed in-depth which was proposed by Hwang Chang.The corresponding formal theory of power analysis attacks are designed,which proved that the simple fixed-value masking can not resist second-order difference power analysis by experimental and theoretical evidence.On this basis,an improved fixed-value masking algorithms ...