Enhancement using chaos of a steganography method in DCT domain

Recently, Steganography is widely used for communicating data secretly. It can be divided into two domains spatial and frequency. One of the most used frequency transformation is Discrete Cosine Transform DCT. There are many techniques based on DCT. The most common is the DCT steganography based on Least Significant Bit LSB. Many proposed methods rely on it such as the LSB-DCT randomized bit embedding based on a threshold. This method is simple and provides some security. In this paper, a secure DCT steganography method is proposed. It allows hiding a secret image in another image randomly using Chaos. The chaotic generator Peace Wise Linear Chaotic Map PWLCM with perturbation was selected, it has good chaotic properties and an easy implementation. It was used to obtain the pseudo-random series of pixels in which the secret image will be embedded in their DCT coefficients. It enhances the LSB-DCT technique with threshold. Many metrics have been evaluated such as Peak Signal to Noise Ratio (PSNR), Structural Similarity (SSIM) Index and the capacity. A supervised universal approach based on Fisher Linear Discriminator (FLD) was used to evaluate the security against the steganalysts. The obtained experimental results demonstrate that the proposed algorithm achieves higher quality and security.