Reversible Data Hiding and Image Encryption in Frequency Domain

With the increasing popularization of information transmissions in recent years, the Internet has become the primary channel of public communication. However, behind this convenience lie information security risks. Many people have attempted to claim other people's documents as their own via theft or alteration. So information transmission protection and certification have become critical issues. In this study, we used the frequency domain to encrypt and hide certification information. We adopted the wavelet transform method to transform the images from the spatial domain into the frequency domain, used RC4 to perform stream encryptions for the visually sensitive LL area, employed reversible information hiding for the LH, HL, and HH areas using the pixel value ordering (PVO) method and permuted the LH, HL, and HH areas to improve the level of security. Finally, we outputted the file using the ZIP compression format. The results indicated that our method provides a good visual encryption effect by enabling users to correctly extract and remove the certification information as well as certify the decrypted image.