  To provide an added security level most of the existing reversible as well as
irreversible image steganography schemes emphasize on encrypting the secret
image (payload) before embedding it to the cover image. The complexity of
encryption for a large payload where the embedding algorithm itself is complex
may adversely affect the steganographic system. Schemes that can induce same
level of distortion, as any standard encryption technique with lower
computational complexity, can improve the performance of stego systems. In this
paper we propose a secure secret image sharing scheme, which bears minimal
computational complexity. The proposed scheme, as a replacement for encryption,
diversifies the payload into different matrices which are embedded into carrier
image (cover image) using bit X-OR operation. A payload is a grayscale image
which is divided into frequency matrix, error matrix, and sign matrix. The
frequency matrix is scaled down using a mapping algorithm to produce Down
Scaled Frequency (DSF) matrix. The DSF matrix, error matrix, and sign matrix
are then embedded in different cover images using bit X-OR operation between
the bit planes of the matrices and respective cover images. Analysis of the
proposed scheme shows that it effectively camouflages the payload with minimum
computation time.
