I would like a solution for cloud storage with the following demand:

  • Secure, (only trust myself and not even the cloud storage provider)
  • Support for versioning
  • Compression

Is these combination the best or would you choose something else?

  • Storage, Dropbox
  • Security, TrueCrypt
  • Versioning Subversion
  • Compression Subversion
  • 1
    Well, Dropbox has storage and versioning taken care of. From the website you can roll back to specific versions of a file and even un-delete them.
    – Wuffers
    Nov 6, 2010 at 15:38
  • 1
    @Wuffers Yes, but you don't want to undo all the file changes when you undo entire encrypted file container. That’s why you need your own file versioning. You have also to download the entire container again. Nov 18, 2011 at 19:49

4 Answers 4


This combination works well, however one should configure TrueCrypt right. You have to uncheck "Preserve modification timestamp of file container" under TrueCrypt options. Otherwise DropBox will not detect changes too virtual drive file.

  • 1
    If you are using multiple computers with the same Dropbox account, remember that even reading the contents of a TrueCrypt will mark it as changed in this case. This will create conflicted copies with dropbox. you can avoid that by opening the container in "read only" mode on other computers.
    – user
    Mar 3, 2014 at 15:58

Maybe create a TrueCrypt container in your dropbox and version the contents with subversion?

Let me know how that goes.


I use Mercurial (or Git) + TrueCrypt + Dropbox for encrypted remote backups

The coolest thing is that Dropbox does NOT sync the entire TrueCrypt container if you modify a small portion of your code. The sync time is roughly proportional to the amount of changes. Even though it's encrypted, the combination of TrueCrypt + Dropbox makes excellent usage of block cipher + block level sync. Setup:

  • Create a Truecrypt container (multiple Gigabyte is fine)
  • Under Truecrypt preferences, uncheck preserve modification timestamp*.
  • Create a repo as mentioned above by Dan ( https://stackoverflow.com/a/1961515/781695 )


  • Quit Dropbox
  • Mount the container, push your changes, unmount
  • Run dropbox

P.S. Unchecking the preserve modification timestamp tells dropbox that the file has been modified and it should be sync'd. Note that mounting the container modifies the timestamp even if you don't change any file in it. If you don't want that to happen, simply mount the volume as read-only


TrueCrypt with Dropbox is probably the most secure way to store data encrypted. However, each time you change even one byte of what's in your encrypted container you'll have to re-upload the whole thing. That isn't very convenient unless you're storing a very small amount of highly encrypted data.

There are some secure alternatives to dropbox (see here: http://skeptu.com/secure-alternatives-to-dropbox) which use software to encrypt your files before they're sent to the servers, rendering them unreadable to the company you are storing them with.

The one advantage your proposed solution has over them is that they are mostly closed source, meaning that they theoretically COULD insert a back door in to their own code. That is less likely with truecrypt (it's open source + the code has been eyeballed a fair few times), although still conceivably possible. For the ULTRA paranoid I would advocate your solution.

  • 2
    DropBox doesn’t upload the entire file/container to the server, it only uploads the changes! How that may be a potential security issue for the encrypted container. It may be easier to break the encryption. Nov 18, 2011 at 19:46
  • I haven't tried it myself, but it seems to be the experience of other users that the entire container gets resync-ed even if only a minor change is made: forums.dropbox.com/topic.php?id=14332
    – Colm
    Nov 22, 2011 at 8:27

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