Implementation and comparative analysis of text steganography methods

Abstract

Steganography is a crucial area of modern information security, designed to conceal data within a carrier so that the very fact of secret transmission remains unnoticed. Among its various forms, text steganography holds a unique position due to the widespread use of the text format, though it faces a significant limitation: low container capacity compared to media like audio or images. Practically, text steganography is key to intellectual property protection, functioning as an "invisible social DRM" (Digital Rights Management). A unique, imperceptible identifier (marker) can be embedded into every copy of an e-book, which doesn't alter the content for the reader but allows for effective tracking of leakage sources or unauthorized distribution. Considering the objective volume constraints of text as a container for hidden information, this article focuses specifically on the comparison and evaluation of methods. The goal was to select approaches that maximize the efficiency of data concealment while preserving the document's original structure and visual appearance. Our comprehensive study chose and practically implemented two core methods: Homoglyph Substitution Method (using different variants of the same character that are visually indistinguishable to the reader but encode hidden data). This approach leverages the variability in character encoding standards (like Unicode) to embed information directly into the character code space, ensuring robustness against simple text copying. End-of-Line Marker Modification Method (where variations in the formatting of paragraphs or lines subtly carry encoded information). This method exploits the redundancy in text file formats (e.g., ASCII/Unicode) regarding the indication of a line break (CR and LF). The results of our comparative analysis convincingly demonstrate that text steganography, even with its inherent capacity limitations, is a promising and reliable tool for the individualization and protection of electronic publications. The application of these two methods ensures a high degree of imperceptibility for the hidden marker and achieves resilience against simple manipulation and copying of the content. This combination of characteristics makes it possible to effectively scale DRM solutions (Social DRM), fostering new, secure approaches to the distribution of sensitive intellectual content. To practically showcase these advantages, a demonstration software implementation was created. This program, which utilizes both steganographic methods combined with additional encryption, clearly validates the potential for merging imperceptibility, resilience, and effectiveness.