Image steganography with N-puzzle encryption

Security, when referred to the context of data/information, is indeed a very vulnerable and necessary entity at present. Rigorous researches are cropping up for the betterment of the secured globe. Primarily, the term ‘Steganography’ has been in limelight to cater the extreme need of protection of sensitive and confidential data. This paper presents a two level steganographic approach of masking the secret data. This is done to facilitate data hiding and hence ensures a covert communication. On the whole, the targeted goal of this methodology is to maintain a trade-off between payload, imperceptibility and robustness. The first stage of the procedure imposes the Arnold transformation on the carrier image. The output of this stage is a scrambled image. This scrambling of pixel data bits disrupts the normal orientation of the resident pixels. Next, an N-puzzle based technique is applied on the scrambled image to promote a strategy of encryption. The concept of N-puzzle problem stands to be the base of this step. Post this stage, the output generated is a further encrypted image. Thereafter, the insertion technique of Mid Position Value (MPV) is applied to embed bits from the secret image within the above generated form of cover/carrier. After the procedure of insertion, the application of reverse N-puzzle encryption technique followed by the inverse Arnold transform fosters the final stego-image. This, on the whole, results in reverting back to the normal orientation of the original input image. All of the given experimental results highlight the outcome of the whole methodology. On this context, several of the quantitative as well as qualitative benchmark parameters have been analyzed. The results computed shows that the quality is well maintained. The generated stego is imperceptible. It also supports the non-detectability of secret data. The payload promoted in this procedure is quite high. Thus, the trade-off between the security parameters is maintained.