StegoCrypt method using wavelet transform and one-time pad for secret image delivery

摘要

In this study, the StegoCrypt technique is proposed using a combination of Discrete Wavelet Transform (DWT) and One-Time Pad (OTP). Cover image with size 512 * 512 transformed with Wavelet transformation of four levels. For the first level to the third level, the subband LL is selected to obtain LL3 subband. At fourth level, the LL3 is then transformed into HH4 subband with help of wavelet transformation. This is done to gain strength and imperceptibility to the stego image. The secret message that is used is a binary image with a size of 32 * 32. Secret image is encrypted with OTP before it is inserted in the host image. To test the quality of imperceptibility, stego images were measured using PSNR and MSE. While the quality of secret image reconstruction of extraction and decryption results are measured by using NCC. Robustness of stego image is also tested with JPEG compression attacks. From the test results can be concluded that the proposed method works well and get a better quality stego image. The secret image reconstruction results are also perfect as well as robust to JPEG compression attacks.