Differential Power Analysis (DPA) is a kind of side channel attack that makes use of statistically analyzed power consumption records to find out secret cryptographic information. Many types Hardware and Software level countermeasure has been proposed to protect DPA. In this paper we have analyzed different types of software level countermeasure of DPA using randomized and fixed value masking technique. And we have introduced a new secure and efficient masking scheme for the intermediate value of an AES SubByte which eliminate DPA scheme.