> For the complete documentation index, see [llms.txt](https://ctf.zeyu2001.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://ctf.zeyu2001.com/2021/yauzactf-2021/lorem-ipsum.md).

# Lorem-Ipsum

Zero-Width Space (ZWSP) Stegonography

## Description

We found this text classified as "Top secret". But we found an ordinary placeholder there. What is the secret?

{% file src="/files/-MiL6zTFtXEDtATbSUFv" %}
lorem-ipsum.txt
{% endfile %}

## Solution

Opening up the file in a hex editor, we can see that there are many zero-width characters hidden in the spaces. This is zero-width steganography, and each of the zero-width characters contain encoded data.

![](https://3167364547-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F-MX1bWRlBzHpEPe1TYDD%2Fuploads%2Fgit-blob-44a2d49115a3635f1d058191ee1ac628fed4621b%2FScreenshot%202021-08-30%20at%204.16.47%20PM.png?alt=media)

Luckily for us, there is a [site](https://330k.github.io/misc_tools/unicode_steganography.html) that implements the decoding for us. We only need to paste the encoded text.

The flag is `YauzaCTF{1_c4n_h1d3_wh473v3r_y0u_w4n7_3v3rywh3r3}`.