Syntactic Steganography Approach for Information Security

Abstract

In today digital age, there are more demands to improve techniques for information security. One of the solutions is steganography, hiding sensitive information within innocentlooking cover media. In this paper, we propose a syntax-based steganography approach by using the syntax bank. The input raw sentence is parsed with the Stanford parser that can produce a phrase structure of the sentence. This parse structure is then used to produce the syntax of the sentence. At the same time, Shannon-Fano coding is used to compress the input secret message as minimum total bits length as possible. Then, syntax transformation task searches the syntax set of the given sentence within the syntax bank, and then transforms it into a desired syntax that can represent the key-controlled semi-randomly generated secret bits intended to hide in the sentence. The resulting stego text will still be innocent-looking by applying semantically unchanged syntax transformation on the input text. Thus, the detection of the secret message may be hard for the intruder.