But how are folder sets stored internally? How do you make sure that the "oppressor" is not able to find out that more than one folder set exists?
It's certainly possible for a highly skilled adversary (e.g. some evil-geek at the NSA) to find out that there is more than one folder set, but that doesn't mean much. Folder Sets, once created, cannot be deleted, and are stored forever in Espionage's database. If you forget the password to a folder set, then you'll never be able to get it back, and you'll forever lose access to all of the folders that were stored in it (unless you copied their passwords manually and saved them somewhere).
For example, I honestly don't know how many Folder Sets I have in my database. I haven't kept track. I've used them temporarily for experimentation and testing Espionage. I've forgotten the passwords to most of them.
Just because someone discovers that you have multiple Folder Sets, doesn't mean they contain anything useful, or even that you know what's in them or remember their password.
PS: IMO the fact that the encrypted sparsebundles themselves can be easily found (e.g. with "find / -name *.sparsebundle" in a Terminal.app window) is already quite a big threat to the "plausibility of the deniability" so to speak. I encourage you to proceed into this direction with a future version of Espionage, think about hiding encrypted images inside of 1080p movie files etc. 
Yes, that's a valid point, however Espionage allows you to store the sparsebundles anywhere you want. You don't have to store them on your computer, that's up to you. If you want, you can store some of them on a USB stick, or someplace else.
The idea of disguising them as other types of files is interesting, however it comes with its own issues. Sparsebundles have files within them that have a sequence of bits that say, "I'm a sparsebundle!". So, in our example of the "evil-NSA geek", if they really wanted to get you, they'd be able to search the entire drive looking for that exact pattern of bits, and they'd find them.
We could do some trickery like encrypting the sparsebundle header files themselves, but I think this is already getting to an area that's a bit too involved and doesn't have much applicability to most users. If you are that paranoid, there are other things you can do that are basically just as effective, and not as involved and convoluted.
We have to prioritize what features we implement, and disguising sparsebundles as movie files, while a very interesting idea, would be difficult to get right, and simply doesn't increase the value of Espionage enough to justify the effort we'd have to put into it. Simply move the sparsebundles onto a thumb drive and breathe easy if that's a concern to you.
If you really want this feature, I think you could actually already do something like it with Espionage's Folder Actions. You, or someone else, could write a script that is run prior to unlocking a folder that extracts a sparsebundle out of some other file (be it a 1080p video or something else), and places it where Espionage expects it. Voila!
Topic: Folder Sets and Plausible Deniability (Read 42860 times)