Hi! Does anyone know if can be added to this list?

No it can’t.

What about Or, does it not make sense to use CM with an E2EE cloud storage service, for added protection?

You do not gain more privacy from e2ee services in addition to using cryptomator, but it’s not harmful either. offers a desktop client, so it can be used with cryptomator desktop. But as far as I know they do not offer a WebDAV interface, so you can’t configure a connection in the mobile apps. If there is an integration in your mobile files app (and this folder is accessible by 3rd party apps, which is often not the case) then you can try to use this „local“ path in combination with the mobile apps. Means you configure a local vault and point to the storage in your files app. I never personally did test this, but I guess it’s worth a try.

Thanks @Michael . I didn’t try to test what you mentioned either, but I just installed the Filen desktop client, which allows you to sync a folder in the Filen cloud, to a local folder on your laptop/desktop, or in my case, a mounted thumb drive (that I can remove and store in a safe, for example).

When I did that, the files downloaded from the Filen cloud to my thumb drive did not appear encrypted, since I could see them without needing to enter a password. I found that odd since Filen is supposed to be E2EE, right??

Anyhow, I do need them to be encrypted on that external drive. So I thought maybe I will need CM after all. I installed the CM desktop client, and created a CM vault on the thumb drive. When revealing the vault, it mounted a “localhost” on my Mac.

Then what I did, was create a folder in that mounted localhost, and I synced it using the Filen desktop client, to a location in my Filen cloud storage.

Now for testing the sync. I put a file from my Mac into the synced folder (in the CM vault), and I put a file into the synced Filen cloud folder, and the sync worked!

Then, I locked the CM vault, and the “localhost” unmounted. The files on the thumb drive are encrypted, which is what I wanted.

This caused an issue in the Filen sync client, which is to be expected, because the local sync folder has disappeared.

Back on my phone, I added more files to the Filen cloud location which is essentially synced to the CM vault on the thumb drive.

Then with CM I unlocked the vault. What I had to do then, was, in the Filen client, go to “Issues”, clear the issue, and resume syncing.

It worked. Within a few seconds, the new files were in the CM vault folder, which is synced with Filen.

So, long story short, I can confirm that on desktop/laptop, Cryptomator does work with to essentially create a synced - and encypted - backup of the Filen cloud storage - even using a thumb/external drive.

If I didn’t use CM though, those files downloaded from Filen cloud would be exposed. So I would say that CM did add more security/privacy to just using Filen by itself.

Now I wonder… Can I view the files if I plug the thumb drive into a separate computer (which has the CM and Filen client apps)? Or is my viewing of the files on the thumb drive tied to that one computer? I guess I can try it out…

I am pretty sure you configured your credentials in the filen app. I cannot imagine how you established a connection to your storage without that.

No, you do not sync the content of that virtual drive (localhost). Then you upload the files without cryptomator encryption. Instead you have to sync the vault files, means the local folder that is named after your vault, with the masterkey file in it and the folder “d”. You can see the path to your vault when you open cryptomator desktop an have a look at the vault list on the left. Below the vault name is the path.

I highly doubt that you synced the encrypted files to filen with your configuration. If you can read the file names of your files when logging into filen with a browser, they are not encrypted with cryptomator.

Yes. But as mentioned, you do not want to sync your file in the virtual directory with your online storage. You want to sync your (encrypted) vault files.

And again no: if you do that, you just add files to your filen cloud. They are not encrypted with cryptomator. You need the cryptomator mobile apps to access a cryptomator vault with your mobile device.

With your sync setting all your files are exposed to filen.
Maybe this helps also: Cryptomator Tutorial: Get Started - YouTube

I am probably not understanding what E2E means. I thought that it meant when I download the encrypted files from Filen to my thumb drive (without CM), they should still be encrypted, unless I want to view them, in which case I have to enter my credentials.

But I’m guessing now that the files are automatically decrypted. It’s not what I wanted, since I wanted the files on the thumb drive to be encrypted.

But then, I won’t be able to view the files in the Filen cloud interface, correct? The files in the cloud interface are already stored encrypted, and I can view them decrypted natively with Filen’s web interface.

Correct. But that’s not what I want. I just want the files on the thumb drive to be encrypted, and that’s where CM comes in. I still want to be able to view the files in Filen cloud.

I must have misspoken initially. I know that the files are encrypted (by Filen) when in the Filen cloud, so I don’t care about having CM encrypted files in Filen that I won’t be able to view in the cloud. But I do want the files to be encrypted on the thumb drive, and the Filen client can’t help with that as far as I can tell.

Right but I trust Filen (unlike the closed source alternatives), and I need to view the files in the Filen mobile app.

So I just tested accessing and viewing the files on the thumb drive plugged into another Mac, and everything worked. CM recognized the vault in the thumb drive, and I was able to link up the same folder in the virtual drive for the 2-way syncing with Filen cloud.

I also tried to get this working on a Windows machine, but the thumb drive was formatted for MacOS only. Looks like I need to format the drive as ExFAT for me to use it on both Mac and Windows machines.