Secure Data Communication using Moderate Bit Substitution for Data Hiding with Three Layer Security

摘要

The paper presents a new method for hiding data in grey-scale images in spatial domain with three layers of security. The basic concept of the proposed method is to embed the desired data in moderate significant bits (MSB) of the image pixels chosen randomly, however, without causing any increase in size of the original cover image. Further, a local-pixel adjustment process is also proposed to reduce any image degradation caused due the effect of substituting data in moderate significant bits. Simulation results revealed that the proposed method ensures reasonable values of image-quality measures (IQM) including peak signal-to-noise ratio (PSNR), mean square error (MSE), entropy and correlation. In fact, this scheme provides two additional layers of security to the hidden data besides providing protection against getting it stolen from image LSB position. The first layer of security to the hidden data is achieved through the attainment of camouflage image. The second layer of security is provided by random choice of image pixel to hide the data and third layer of security is achieved through random choice of bit position in the image byte where embedding of the message bit is to be done.