[Perceptes]

I'd never heard of Boxcryptor. Does anyone else use this? I'm not sure I understand why I need to sign up for an account to use it if its entire purpose is to do client-side encryption.

Also, it's not quite the same functionality, but this also reminds me: For a long time I've used Knox (by AgileBits, the same company that makes 1Password) for encrypted disk images, but they no longer sell or maintain it. It works just fine, but I should probably find a replacement that's still maintained, at least for security updates. Anyone know a good alternative? VeraCrypt (mentioned in the article) seems like one possibility.

[robertjfclarke]

Veracrypt is a great piece of software, but it isn't as easy to integrate across various platforms. Boxcryptor is great because they have iOS/Android/etc. apps.

[daveidol]

Try Cryptomator instead! It's free and open source and does essentially the same thing (no account required)

[bootlooped]

You must sign up for an account to use Boxcryptor because it is paid software. That is the only reason as far as I can tell. As far as I know their servers do nothing for you once you have installed the software on your devices.

[hrunt]

Boxcryptor[1] started out as an EncFS[2] implementation. At the time, EncFS was the only real good solution for file-based encryption. Solutions like TrueCrypt are disk-based, which means for cloud syncing solutions like Dropbox, one file -- the entire disk volume -- gets synced, and every time a file changes, the entire disk gets synced again. EncFS encrypts individual files, which works great for file-based syncing services.

Boxcryptor offered a client for macOS, Windows, Android, and iOS that worked really well, and if you needed Linux support, one could install EncFS and use it transparently on that platform. Boxcryptor charged for a creating volumes with more advanced EncFS settings, but if you created the EncFS volume with those advanced settings using EncFS itself (e.g. on a Linux machine), the free version of Boxcryptor could read and write those volumes with those settings.

In 2013, the people who ran Boxcryptor wrote a second version that implemented a proprietary, unpublished encryption and/or file management scheme. They relegated the previous version to an unmaintained Boxcryptor Classic product and eventually removed it.[3] The proprietary version is what is offered today.

IF you want Boxcryptor-like functionality today, the EncFS4win project[4] is a good solution for Windows. EncFS can be installed via Homebrew[5] on macOS and its volumes mounted via a shell script or some FUSE GUI managers. You can install EncFS on Linux and use gencfsm[6] for a GUI manager. The Windows, macOS, and Linux implementations all use FUSE for exposing the encrypted files via a native filesystem interface. For Android, Encdroid provides an application browser for volumes. I am unaware of an iOS solution. I use the FUSE systems to keep certain sensitive cloud documents synced between my Windows, macOS and Linux machines while still being able to edit and use them like normal files on those systems.

EncFS does have a few attack vectors they have been slowly addressing. It also suffers from the same problem that all cloud-synced file-based encryption systems suffer; someone could restore your cloud files to a previous known version without your knowledge. The file-based encryption does not prevent what is in effect a replay attack. A research paper proposed a solution -- CryFS[7] -- with some solutions for this problem, but the implementation is immature.

(edited for formatting)

1. https://www.boxcryptor.com/en/

2. https://vgough.github.io/encfs/

3. https://www.boxcryptor.com/en/blog/post/6-years-of-boxcrypto...

4. https://encfs.win/

5. https://formulae.brew.sh/formula/encfs

6. https://moritzmolch.com/apps/gencfsm/

7. https://www.cryfs.org/