Hiding information in the placement of maneuverable words

Word order is usually crucial for maintaining meaning and syntax integrity of English text. However, there are some cases where certain words and phrases can be relocated, while still preserving the syntax and meaning of the sentence. In this paper, we present a syntactic transformation scheme for hiding information (secret message) in plain English text. The hiding scheme is based on transformations which relocate maneuverable sentence constituents in order to hide bits of the secret message. For example, if a subordinating conjunction is found in the text, the two clauses of the corresponding conditional statement can be swapped to hide one bit. The size of the hidden text depends on the size of the cover, and more importantly, the number of maneuverable sentence constituents available. We present a statistical analysis, based on the Google Books Corpus, that shows the number of bits that can be hidden through our set of transformations in a typical English statement. We show that our proposed scheme can embed more than 0.8 bits per sentence.