Text Steganography Tool Experimental
Subtly hide a secret message within ordinary-looking text using invisible Unicode characters. You can also attempt to decode messages that might have been hidden this way. This technique is for casual message concealment, not for high-security applications.
Text Steganography Encoder and Decoder
Encode: Hide Your Secret Message
Decode: Reveal Hidden Message
Important Considerations & Limitations:
- Not Cryptographically Secure: This method hides data using invisible characters, which is a form of "security through obscurity." It is not a replacement for proper encryption if you need to protect highly sensitive information.
- Detection & Stripping: Software that analyzes text (like some email clients, social media platforms, or text editors) might detect, alter, or remove these invisible zero-width characters, potentially corrupting or revealing the hidden message.
- Message Length: Longer secret messages result in more hidden characters being embedded. This increases the file size slightly and might make the steganographed text more susceptible to corruption or detection by systems that limit character types or string lengths.
- Platform Compatibility: Always test the steganographed text on the intended platform or application to ensure the hidden message remains intact and the cover text displays correctly.
- Purpose: Best used for fun, casual message hiding, or as an educational example of steganography principles.
How This Text Steganography Works
Steganography is the art and science of hiding information by embedding messages within other, seemingly harmless messages or data (the "cover" medium). In this tool, we use text steganography specifically with zero-width characters.
- Convert Secret to Binary: Your secret message is first converted into a sequence of binary digits (0s and 1s). Each character typically becomes 16 bits in binary to support a wide range of characters (Unicode UTF-16).
- Map Binary to Zero-Width Characters: Each binary digit (0 or 1) is then mapped to a specific invisible Unicode character:
- '0' might be represented by a Zero-Width Space (ZWSP - `\u200B`).
- '1' might be represented by a Zero-Width Non-Joiner (ZWNJ - `\u200C`).
- Embed in Cover Text: This sequence of zero-width characters, representing your binary secret message, is then embedded within the cover text. To make decoding possible, special invisible "marker" sequences (also made of zero-width characters) are usually placed before (START_MARKER) and after (END_MARKER) the hidden payload. This tool appends the markers and payload to the end of the cover text.
- Decoding: The decoding process looks for these start and end markers. If found, it extracts the sequence of zero-width characters between them, converts them back to their binary representation (0s and 1s), and then converts the binary string back into readable text.
The result is that the steganographed text looks identical to the original cover text to the human eye because the added characters have no visible width. However, they are present in the underlying data of the text string.
Frequently Asked Questions (FAQ)
What are zero-width characters?
Zero-width characters are special Unicode characters that, as their name suggests, do not take up any horizontal space when rendered. Examples include Zero-Width Space (ZWSP), Zero-Width Non-Joiner (ZWNJ), and Zero-Width Joiner (ZWJ). They are typically used in text processing for specific linguistic purposes (like controlling word breaks or ligatures) but can also be exploited for steganography because they are invisible to the naked eye.
If the characters are invisible, how can the message be found?
While invisible to direct human sight, these characters are still part of the text's underlying data. Software designed to analyze text content, or even simply copying and pasting into some editors that reveal all characters, can expose their presence. This tool uses specific start and end marker sequences (also made of zero-width characters) to identify where the hidden message begins and ends, allowing it to be extracted.
Is there a limit to the length of the secret message?
Technically, no strict limit is imposed by the tool itself. However, longer secret messages will result in a larger number of zero-width characters being embedded into the cover text. This increases the overall size of the steganographed text (even if it looks the same) and makes it more likely to be detected, corrupted, or truncated by systems that have limits on text length or that actively strip such characters.
Can I use any type of text for the cover text and secret message?
Yes, you can generally use any text, including different languages and emojis, for both the cover text and the secret message. The tool converts characters to their Unicode binary representation. However, very complex or rare Unicode characters in the secret message might lead to longer binary strings and thus more hidden data.