Syncing TrueCrypt Volumes (across a windows network)

I have been looking for a way to synchronise an encrypted Truecrypt  volume. This is a tricky problem, as a truecrypt volume is simply a large (possibly several GB) file, which appears as a disk drive when mounted with truecrypt. I have been looking into this technology lately as a method to have a safe location to store documents which which can’t be accessed by anyone else. Truecrypt is perfect for this, and as I have been listening on security now lately, it is still pretty much a very impressive solution for encryption on windows – and it’s free. I have heard bad things about dropbox being able to access your whole computer and similar things so truecrypt seems a perfect solution. So I’m very satisfied using the various simple to use options truecrypt has, the next problem is backup. I want to be able to backup my encrypted volume. The encrypted truecrypt volume is simply a large file sitting on my computer, each time I modify the contents of the volume, the encrypted volume changes. Herein lies the problem, I need to be able to backup only the part of the volume that has changed – otherwise for example if I change the name of a file in the truecrypt volume, the whole volume would need to be resynchronised with the backup location. This is called Block level synchronisation, where only modified parts of a file are synchronised. Dropbox does Block level synchronisation, so it is possible to use dropbox with a truecrypt volume – but that still has the problem of using dropbox… The best source of various solutions I found is here. The one I have got to work is Syncovery, there are others on GitHub which were free, but Syncovery seems the best option – even if it does cost ~$35.

This allows me to have a remote backup of a truecrypt volume – where the remote location doesn’t need access to the contents of the volume. With this solution only encrypted noise is sent out of my computer to the backup 🙂

To get this to work:

  1. Create Truecrypt volume (needs to be a volume not a partition so the sync software can access the encrypted data).
  2. Set truecrypt to change modification date when modifications are made. (Settings>Preferences>Windows>Uncheck Preserve modification…)
  3. Create Syncovery Profile (with block level mode).
    – Select Advanced Mode from the start screen
    – Create New profile with Standard Copying mode
    – Select Partial File Updating (in the Special tab sheet)
  4. Since my backup drive is portable, I attached it and synchronised it locally.
  5. After the first synchronisation, it will create a database of the files, so the second time should be much faster. I tested this by putting the backup on a remote machine over wifi and making a small change to the contents of the source truecrypt volume. It ran through the whole 12GB volume in no time at all 😀

2 thoughts on “Syncing TrueCrypt Volumes (across a windows network)”

    1. I forgot that I even downloaded syncovery. You can just copy the truecrypt volume to an external drive connected to an RPi. Then on the remote client machine attach the folder containing the truecrypt volume as a network drive, you can then mount the truecrypt volume within the attached network drive. From here you can use a free tool like Allway Sync..

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