Information Technology Reference
In-Depth Information
10
Minimizing the Stego-Image Quality
Impact of Message Embedding Using
the DM All
ocation Method
Chin-Chen Chang, Wei-Liang Tai, and Chia-Chen Lin
CoNTENTS
10.1 Introduction .............................................................................................. 216
10.2 Message Embedding ............................................................................... 217
10.3 Conventional ±1 Steganography............................................................ 220
10.3.1 Least-Significant-Bits Embedding ........................................... 220
10.3.2 Ternary Embedding .................................................................. 221
10.4 Proposed Scheme..................................................................................... 222
10.4.1 DM Allocation Method ............................................................. 222
10.4.2 Embedding Process ................................................................... 224
10.4.3 Extraction Process...................................................................... 224
10.4.4 Example of Embedding and Extraction.................................. 225
10.5 Performance Analysis ............................................................................. 225
10.6 Conclusions............................................................................................... 229
References............................................................................................................. 230
Message embedding is the art of covert communication in which secret
messages are embedded into innocuous looking objects, known as covers,
through slight modification. The covers concealing secret data are called
stego objects. The goal of message embedding is to embed a secret message
so that its very existence in the stego object cannot be revealed. Thus, secu-
rity is mostly influenced by the embedding efficiency, which is the number
of bits embedded per embedding change. In this paper, we will show that a
disk modulo method called DM can be used for covert communication with-
out sharing the placement of embedding changes. This allows construction
of message embedding methods with improved security. We then describe
an efficient message embedding method for minimizing the embedding
impact using a DM allocation method with the goal of decreasing the num-
ber of embedding changes. Finally, the embedding efficiency of the proposed
method is compared with theoretically achievable bounds.
215
