Syntax Bank and HMAC based Syntactic Steganography Approach for Information Security

Abstract

Steganography plays an important role for information security in today digital age. Because of the widespread usages of natural language, we propose a linguistic steganography approach based on syntax bank and HMAC in this paper. The proposed system first uses the combination of most popular two lossless data compression methods to compress the input secret message. At the same time, the system extracts the syntax of the incoming cover text sentence. Then, syntax set creation task constructs the syntax set of the given sentence with the help of the syntax bank. The syntax transformation step then transforms the input sentence into a desired syntax that can represent the key-controlled semi-randomly generated secret bits intended to hide in the sentence. In addition, we apply SHA 512 hash algorithm to generate keyed-hash message authentication code (HMAC) in order to present the identity of the resulting stego text. 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.