[BirbSingularity]

Hey there. I must have missed the section that handles encrypting the session key, my bad.

It's more the struct method of embedding though that I was emphasizing. Structured encrypted data has high entropy which can give away it's presence. Try running some of your before and after images through aperisolve or the cyberchef entropy analysis tool and see how the analysis changes.

https://www.aperisolve.com/

https://gchq.github.io/CyberChef/#recipe=Entropy('Curve')

[lobito14]

Here are the results of the Entropy Curve analysis:

Original: https://cloud.screenpresso.com/g5MIc/2024-01-25_01h15_08.png

With hidden data: https://cloud.screenpresso.com/lIvFc/2024-01-25_01h11_22.png

The differences appear to be on the right side of the spectrum, which I assume is the end of the file where the hidden data is stored. The CyberChef tools are awesome, thanks!

Here are the Aperisolve results:

https://www.aperisolve.com/1f1b2593242e7e690101155741f40aa0

Aside from the string results, everything seems normal here.

[lobito14]

No problem, your suggestions are always welcome. I managed to reduce the high entropy by base64 encoding the encrypted data. Meanwhile, I've developed CryptoFrame (https://github.com/x011/CryptoFrame), which hides encrypted data inside a video, split across multiple frames. It uses stegano LSB under the hood but adds a layer of encryption, which is missing in stegano.

I'll definitely give apersolve.com a try, although it's a pity it only handles images, since File Hider can be used for all types of files.

P.S.: Sorry for the late reply, but I became a father about a week ago. :)