Implementation of Discrete Cosine Transform and Permutation-Substitution Scheme Based on Henon Chaotic Map for Images

The use of images from the internet that are not obtained from their creators is a copyright infringement. Illegal access to confidential images can be detrimental to the owner of the image. Things like this can be prevented by securing digital images through steganography and encryption processes. The methods that can be used to perform steganography and secure encryption of images are the Discrete Cosine Transform (DCT) method and A New Permutation-Substitution Scheme Based on Henon Chaotic Map for Image Encryption. Encryption uses the Henon Map algorithm to generate a key and the encryption process is carried out by randomizing each pixel in the image then XOR is performed to encrypt the color of the image. The DCT method is a lossy compression scheme where
$\mathrm{N}\times\mathrm{N}$
blocks are transformed from the spatial domain to the DCT domain. The results of this study can hide and secure the image using a Discrete Cosine Transform and A New Permutation-Substitution Scheme Based on Henon Chaotic Map. The best combination of key-value
$\mathrm{X}_{0}=0.017$
and
$\mathrm{Y}_{0}=0.061$
. The result stego image is resistant to 0.1% noise attacks but is not resistant to 1% noise attacks and changes in contrast because the value of pixel changes too much so it can affect the message image that hides in the cover image.