Does Cryptomator download all data for decrypting?

Ok, this may seem to be a stupid question but I’m not fully into cryptography.

My question is basically if Cryptomator downloads all data regardless if I open a file or not.

My scenario is as follows:

  • I want to upload a folder from my local machine to my cloud storage provider
  • I want to include this folder on other devices low on storage
  • the other devices should download the files only when I try to open them

Everything is working with Cryptomator but I’m not sure if I will quickly run out of space on the said devices. The cloud storage is included via WebDAV and SSHFS currently.

It depends on the device.
If you are using the android or iPhone app, then the answer is no. Only the files you want to read are downloaded for decryption

If you use a desctop app, then it depends also.
If you are using Cyberduck as 3rd party app for direct accessing you vault, then the files are downloaded and decrypted on demand.
If you are not using a 3rd party app and store your decrypted files in Cryptomator WebDAV network drive, then you’ll have to use the sync client of your Storage provider to sync the encrypted files to the online storage. In that case obviously all the encrypted files are always on your device as well.

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Hi Michael,

thanks for your reply! To see all the different options was really helpful.

And thanks for pointing to Cyberduck! This seems my way to go.

Hey there, I would like to ask a question on this topic.

I am currently using Google Drive File Stream (DFS) as a sync client for my files on Google Drive, and I am aware that it only requests the specific bits requested from a file (if one opens a video, it will start playing right away, since it makes the requests from the beginning).

I noticed that it takes a rather long time for the cryptomator vault to open the contents of the file, and I suppose it is due to DFS only receiving/making one request at a time. After a while waiting, it shows a “(directory) is not accessible. Insufficient system resources exist to complete the requested service.”.

My doubt on this is if the request made by cryptomator do the file system (and therefore, to DFS) is specific about what piece is necessary at the moment, or if everything is fully downloaded, either for it being impossible to make requests of pieces on encrypted files (is it? what about thumbnails and just names?), or for such feature not existing.
Just trying to better understand how things work.

P.S.: After the error, which takes like 20 seconds to appear, if I click on the folder again, the folders within are displayed more quickly (why is that?). I have also tried to use Cyberduck, as mentioned by @Michael, which works wonderfully to see what is in those folders and get stuff on demand (not as well as the mountain version, but thats acceptable).

To integrate your unlocked vault into the system, Cryptomator can choose between three different technologies: WebDAV, Dokany (windows only), FUSE (unix).

Your shown error message indicates that you are using Dokany. It means that the file system call (here directory listing) reached a timeout and therefore Dokany gives up on that call (and even unmounts the whole drive). The workaround is by increasing this timout threshold with the vault specific mount options.


Regarding the question if everything is fully downloaded: There was a discussion specific to Google Drive File Stream, see Drive File Stream Quota Management · Issue #1093 · cryptomator/cryptomator · GitHub.

In the end it seems that, even if only a certain part of the file is accessed, the whole file is downloaded when Dokany is used.

Oh, now I think I get what it means. I will turn on the notifications for that issue.

Indeed, when I changed to WebDAV on the settings I did not experience any problems opening folders or seeing their names and extensions. Sadly, neither way permits the use of the “stream” feature, and the file is downloaded in full (the same is applicable when seeing thumbnails, apparently).

Thanks for replying :slight_smile:, the content was very useful to understand and I can now browse my files without using Cyberduck or Mountain Duck (which had problems transferring more than a few files).

To integrate your unlocked vault into the system, Cryptomator can choose between three different technologies: WebDAV, Dokany (windows only), FUSE (unix). rubeus: … In the end it seems that, even if only a certain part of the file is accessed, the whole file is downloaded when Dokany is used.