A High Capacity PDF Text Steganography Technique Based on Hashing Using Quadratic Probing.

In this paper, a novel approach of PDF-based text steganography is presented. A covert communication is achieved by embedding secret information at between-characters positions of words within cover PDF text. A stegoencoding technique is being designed to improve the embedding capacity along with sufficiently reduced overheads of stego-cover PDF file. The proposed method constructs multilevel embedding capacities which can be used according to requirements from higher embedding capacity to typical embedding capacity. Encoding and decoding of secret text is being obtained by implementing quadratic probing of hashing technique that builds up a direct encoding table which provides better performance in term of time complexity. Exploratory outcome exhibits that the proposed technique gives productive algorithms in term upgraded security and high payload of concealed data. Experiential verification and examination of the proposed technique with certain prominent text steganographic techniques demonstrate that proposed technique performs better than current methodologies and free of requirements like shading scheme, languages, wordlist, compression and so forth. [ABSTRACT FROM AUTHOR]