Hierarchical Visual Secret Sharing Scheme Using Steganography

The rapid growth of computer networks and technology constructs a favorable environment that can tolerate the multiusers in a hierarchy based. In any organization the personnel are frequently organized in the form of a hierarchy and there is the requirement that information is distributed over the hierarchy on a "need-to-know" basis. In this paper, we propose a new hierarchical visual secret sharing scheme, where steganographic technique has been used to maintain hierarchy and detect fake share using weight matrix-based embedding method. In this approach, we have used a key matrix (K) and a weight matrix (W) to hide critical information (M) into the share on each level of our proposed scheme. The basic ideas are: (i) to use an EXclusive-OR operator to protect the key matrix (K) and (ii) to use a weight matrix (W) to increase the data hiding ratewhile maintaining high quality of the share image in each level in hierarchy of the scheme. The share generator or Trusted Authority (TA) generates weight matrix Wi for share Si and each level modifies weight matrix Wi+1 using the formula Wi+1 = (W-i x 5 mod 8) + 1 where i = 0, 1, 2,..., n to keep track of level and maintain the hierarchical structure in proposed scheme. The experimental results are demonstrated and tested using Peak Signal-to-Noise Ratio (PSNR) value and relative entropy. It shows that our scheme is superior in terms of PSNR compared to existing schemes.