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 😀

Air-stream community wi-fi link

Yesterday I finished the install of a Wireless Access point I’ve been working on for a while. It consists of a high gain wifi antenna on my roof, connected to an access point, and thats connected to my home computer network. The Access point is a Mikrotik RB411UAHR built into a Jaycar 5050 Aluminium enclosure ( with the plastic cover from an A4 folder to insulate the board :p ).

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The Antenna is a 24dBi Grid antenna I’ve had sitting around for a while. Because we’re renting here I designed an antenna mast that is removable. To do that I took measurements of the chimney and built a mast..

I ran a network cable I had sitting around down the chimney and into a Power over Ethernet adapter. In order to align the antenna I used trusty google earth.

ant_alignBuild Photos: