A Cross-Number-Based Hiding Method against Visual and Statistical Analysis

In this paper, we present a hiding scheme resistible to two popular steganalysis tools, the so-called visual attack and the Chi-square attack. The goal is to embed secret data in a cover image that maintains well both in the visual appearance and statistical property of the stego-image. In the proposed method, the crossnumber (CN) of a block's bitmap is defined as the count of bit-value changes when the bitmap is scanned in reverse spiral order. Therefore, CN corresponds to the non-smooth level of the bitmap. For each non-uniform block of a cover image, a message bit is embedded in the bitmap with the largest CN value. The embedding procedure is performed by maintaining the coherence between the value of the hidden bit and the bitmap type without changing the CN value of the largest CN bitmap of the block. Experimental results show that the proposed method can pass the visual attack and Chi-square attack.