I want to use steganography for blob files (video files). Can anyone point me to the right direction? Is it even possible?

Of course it’s possible.

There is a lot of data in video, and the viewer won’t notice if anything is off a tiny bit. Depending on encoding, you could hide data in a lot of different places. Adding noise to the audio, shifting colors to encode one bit per pixel (even vs odd), add data in subtitles (past the end), shifting headers, etc. You can hide data pretty much anywhere.

@Root Well, technically everything is possible.

@Root

I guess it’s better if I tell you what I actually want to do.

I have a list of video files, which I want to store as blob files. Whenever user fetches those files, I want to embed user UID directly, hence, if someone decides to publish one of the video files to the piratebay or other site, I will know who did it. These video files are huge, so performance is an issue here.

@yehaaw So, a watermark.

I won’t help you as what you are doing goes against my morals.

@Root You’ve peaked my interest. Why does it go against your morals? I have to secure a huge amount of paid content. To make this content an entity X had to pay a huge amount of money. Now, I’m someone who uses the piratebay daily (since I was a kid), however, I do think that what I am doing is basically stealing. I don’t know, change my mind I guess.

@Root Also, I don’t care which user published it. I want to know which B2B client had that user.

P.S. Yes, white-label solution here.

@yehaaw What goes against my morals is that it tracks an individual user. I’m against tracking of almost every sort, especially on a per-person basis.

Protecting content is fine; tracking users is not. Especially because “technologies” like this are always, always abused.

@Root

Fair enough. Could you recommend me a way to tackle my problem without user tracking? I could just embed B2B client name. Any other ideas?

@yehaaw Let me think about it. No guarantees of course :)

@Root 🤞

Thank you nevertheless

It's nice that you don't need much encoded. Root was right that it depends. Blob is useless blob doesn't tell you anything about meaningful and not meaningful data. Video containers and encodings do allow for these kind of things (e.g. https://matroska.org/technical/...).

Might not be a solution as it is still tracking but you can get control over the use of this info: PKI. Only you hold the private key and don't give it to anyone. The public key is used to encrypt the user id and timestamp. So only when shit his the fan you use this power.

Do note that the users account could be cracked so it's not necessarily a malicious user.

Is it not enough to add a signature. Probably are open source tools to do that. You can legally go after the published vids. No users tracked (avoiding a legal mess even when you do encrypt)

@hjk101 Thank you! Will look into it