Steganalysis of stegostorage library

Gulášová, Michala ; Jókay, Matúš

Tatra Mountains Mathematical Publications, Tome 65 (2016), / Harvested from Mathematical Institute

Résumé

ABSTRACT. The main goal of this research is the detection of the secret messageshidden in JPEG files, which were embedded by StegoStorage library. Thistool allows the user to embed any type of information into a folder of images.Sequential, pseudo-random or Hamming code-based embedding into the least significant bit (LSB) of DCT coefficients is possible. It is possible to choose whichfraction of capacity the cover files are filled.The aim of this contribution is to test the statistical LSB embedding model(modified weighted-stego analysis) for all modes of embedding which StegoStoragelibrary offers, and for all cover files capacities, respectively. Another goal is toimplement a more appropriate type of steganalytic attack for Hamming codes andtest it. For this purpose, the RS (Regular/Singular) steganalysis was selected.The detectability of the LSB embedding model of sequential embedding ispossible from the first percent of filling the cover files. In the case of pseudorandomembedding, the secret message can be detected from approximately 10percent of the cover files capacity filling. Hamming codes were undetectable usingthis type of attack.In the case of attack by RS steganalysis arose another situation. When sequentialor pseudo-random embedding were used, the results indicated the detectabilitysince approximately 5 percent of capacity filling the cover files. The capacityfilling of 5 percent corresponds to 2.5 percent of DCT coefficient changes fromthe original media in the case of sequential embedding. This value, 2.5 %, is thethreshold for the utilization of Hamming codes, too. Therefore, Hamming codes(7, 4), (15, 11) and (32, 26) indicated the detectability, because they exceededthat limit.

Détail

Publié le : 2016-01-01
DOI : https://doi.org/10.2478/tatra.v67i0.455