Use CLI tools jdvin & jdvout with a JPG image, to embed or extract any file, up to 2GB (cover image + data file).
Compatible hosting sites, listed below, have their own much smaller image size limits:
- Flickr (200MB), ImgPile (100MB), ImgBB (32MB), PostImage (32MB), Reddit (20MB / -r option),
- Limit measured by data file size: Mastodon (~6MB), Tumblr (~64KB), Twitter (~10KB).
There are many other image hosting sites on the web that may also be compatible.
jdvrif partly derives from the technique demonstrated by security researcher David Buchanan.
Image credit: @rdc768 / PIN: 3611019770
Your embedded data file is compressed (depending on file size & type) and encrypted with PIN protection.
The file, if required, is split into multiple 64KB APP2 Segments (ICC Color Profile) within the JPG cover image.
(You can try the jdvrif Web App, here, if you don't want to download and compile the CLI source code.)
user1@linuxbox:~/Downloads/jdvrif-main/src/jdvin$ g++ main.cpp -O2 -lz -s -o jdvin
user1@linuxbox:~/Downloads/jdvrif-main/src/jdvin$ sudo cp jdvin /usr/bin
user1@linuxbox:~/Desktop$ jdvin
Usage: jdvin [-r] <cover_image> <data_file>
jdvin --info
user1@linuxbox:~/Desktop$ jdvin Cover_Image.jpg Hidden_File.zip
Saved "file-embedded" JPG image: jrif_12462.jpg (143029 bytes).
Recovery PIN: [***2166776980***]
Important: Please remember to keep your PIN safe, so that you can extract the hidden file.
Complete!
user1@linuxbox:~/Downloads/jdvrif-main/src/jdvout$ g++ main.cpp -O2 -lz -s -o jdvout
user1@linuxbox:~/Downloads/jdvrif-main/src/jdvout$ sudo cp jdvout /usr/bin
user1@linuxbox:~/Desktop$ jdvout
Usage: jdvout <file_embedded_image>
jdvout --info
user1@linuxbox:~/Desktop$ jdvout jrif_12462.jpg
PIN: **********
Extracted hidden file: Hidden_File.zip (6165 bytes).
Complete! Please check your file.
To correctly download images from X/Twitter or Reddit, click the image in the post to fully expand it, before saving.
jdvrif_cli_twitter_pin.mp4
To create "file-embedded" JPG images compatible for posting on Reddit, use the -r option with jdvin.
From the Reddit site, click "Create Post" then select "Images & Video" tab, to post your JPG image.
To correctly download an image from Flickr, click the download arrow near the bottom right-hand corner of the page and select Original for the size of image to download.
With X/Twitter & Tumblr, the small size limits (~10KB / ~64KB) are measured by the data file size and not the combined image size. As the data file is compressed when embedded, you should be able to hide files larger than 10KB or 64KB. For example, a 50KB workflow.json file compressed down to 6KB, making it compatible with sharing on X/Twitter.
Also with Mastodon, the size limit is measured by the data file size and not the combined image size.
For example, if your cover image is 1MB you can still embed a data file up to the ~6MB size limit.
jdvrif_web_pin.mp4
This project makes use of the following third-party library:
- zlib: General-purpose compression library
- License: zlib/libpng license (see LICENSE file)
- Copyright (C) 1995-2024 Jean-loup Gailly and Mark Adler