Highly Imperceptible and Reversible Text Steganography Using Invisible Character based Codeword

Text steganography method can be applied for protecting privacy and authenticity of text-based documents. Text steganography is a challenging task as slight modification in text file can be identified. In general, imperceptibility of text steganography is very poor. Additionally, data hiding capacity of text steganography is very less. Current research works fail to solve both imperceptibility and capacity problems simultaneously. We propose a novel data compression based reversible text steganography scheme addressing both imperceptibility and capacity problems of text steganography. Our proposed method embeds secret message within text file as invisible character by following a set of embedding rules. We present experimental results that demonstrate higher imperceptibility and capacity of proposed method without increasing size of text file containing secret information. Most importantly, our proposed method successfully retrieves secret information and reconstructs original text file without any error.