Method and system for embedding covert data in a text document using space encoding

Abstract

A method and system for embedding covert data in a text document using space encoding. The space encoding changes the inter-word spacing and / or inter-character spacing within a text row to a particular format such that the data is essentially visually hidden in the text document.

Description

field of invention [0001] The present invention generally relates to a method and system for embedding covert data in text documents using spacing coding. Background technique [0002] Digital watermarking is a well-studied field in the signal processing community. Many techniques have been devised for stealthily hiding information in text and image documents. Hiding data is often referred to as "steganography" in cryptography circles. Steganography for text and image documents is quite different, since modifying pixels in images has less visual effect than modifying pixels in text. Therefore, existing steganography techniques for image documents are not directly applicable to text documents. [0003] Traditional methods of hiding data in text documents include: dot coding, pitch modulation (line shift coding, word shift coding), brightness modulation, halftone quantization, component control, and syntax methods. [0004] Each traditional method has its own advantages an...

AI Technical Summary

Problems solved by technology

For example, dot encoding has high data hiding capacity but is susceptible to printing and scanning of text documents because of the noise and interference introduced when decoding the dots

Syntax methods, on the other hand, are recoverable for printing and scanning, but have low data capacity and are not self-validating

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