A Novel Method for Distributed Image Steganography

Distributed Image Steganography (DIS) is a new method of concealing secret information in several host images, leaving smaller traces than conventional steganographic techniques and requiring a collection of affected images for secret information retrieval. DIS, compared to other conventional steganographic techniques, can improve security and information hiding capacity because DIS leaves reduced signatures of hidden information in host images. This paper presents a novel technique for Distributed Image Steganography based on Shamir's (k, n) threshold based secret sharing scheme. An 8-bit, gray level, Secret Image of size P x Q is divided into several sections and embedded inside n-Cover Images of size M x N and only k-Stego Images (k <= n) are required to retrieve the secret image. The size of the secret image is also embedded inside every cover images, so that the stego images become standalone information to the receiver. Experimental result shows that the proposed novel method has high capacity and good invisibility.