In the present paper, an approach which eventually leads to a watermarking technique is proposed, which is based on the principle of recording two interferograms of an image which is phase modulated at two different planes, during propagation to the recording plane. The mark image is hidden as phase information in the second phase mask. Conjugate of the mark image is neededfor successful reconstruction of the host image and thereby higher level of information security is achieved. The method of two interferogram detection is useful for DC and twin image free host image reconstruction.