It's nothing new, steganographic encryption is used as long I remeber, to hide messages into texts, images, videos and even music. There are a lot of tools out there which everyone can use. The advantage is, that an normal encrypted message can cause suspicions, but not so an inocent selfi from the beach, a cat photo, an mp3 of an summerhit, or an "unencrypted" text message, all these can be a container for hidden messages. It can also be used for invisible watermarks for an copy protection, but also for evil uses in autoexecutables malware in images or mp3 files, as seen in the past.

https://stegoshare.sourceforge.net/

https://github.com/Jpinsoft/DeepSound

https://github.com/syvaidya/openstego

https://www.ssuiteoffice.com/software/ssuitepicselsecurity.htm

https://github.com/KuroLabs/stegcloak

https://github.com/fabienpe/MP3Stego

and several more, I listed only the free and OpenSource apps

This is kind of how VeraCrypts hidden partition feature works.

You start the process of the volume's encryption and set a "false" password for it. It creates a partition that is encrypted with that password. When it finishes, you mount it and store "fake" files, the files you would reveal under duress. Veracrypt then takes in a second password and creates a "hidden partition" in the remaining free space of the disk - to be clear, that memory space still reports as unused/free if investigated, but the partition is there.

You can then mount that with your second password and store your actual files. You can work with files and folders in the hidden partition as needed, however if anything is added or changed etc in that first fake partition, the data in the hidden partition will be corrupted by those actions.

This means that so long as you plan ahead, someone can literally put a gun to your head and demand the password to the encrypted disk, and you can give them one that works without revealing the data to them.

In theory, since the data in the hidden partition is encrypted and unreadable, it is impossible to detect that it exists in the "unused" space of the disk, even by a forensic analyst. To them it would just look like old, randomly flipped bits that came from previous usage followed by a quick format.

Now, what's really cool about this is that if you use the veracrypt bootloader, you can store and boot from an undetectable OS you store in that hidden partition, while having a decoy operating system on the visible partition:

https://veracrypt.io/en/VeraCrypt%20Hidden%20Operating%20System.html

I recall truecrypt having this as a file system feature where you could decrypt two different filesystems on the same volume.

One password would show you files you didn't care much about if anyone got them, the other password would show you the actually important files.

This way there was always a realistic method to say "this is it"

You want to check out steganography if you haven't yet!

First I heard about it , very interesting though. Found a paper on archive https://arxiv.org/html/2505.23772v1

I posed this in another 'obfuscation' thread, but in the case of steganography, wouldn't AI have the ability to 'see' that the a file, say a image' has odd bits in it that shouldn't be in an image? Even further, would it be able to ascertain that you have two levels of messages hidden inside the image? It sounds similar to what you can do with ~~VeraCrypt~~ Cryptomater in that you have two 'levels' of encrypted data. One to reveal to the authorities and one that's for the intended target of the data packet.