4 ms·

Great, now only if they actually encrypted my files.

by batgaijin 14y ago

matwood 14y ago
Put a truecrypt volume in your DropBox. Why rely on someone else to do the encryption?
- mapgrep 14y ago
  If Dropbox were designed to handle sequentially-numbered blobs of encrypted data, changing one file would require your other devices to download only that file (an encrypted blob of roughly the same size). With a TrueCrypt volume or other encrypted file solution on top of Dropbox, you have to resync the entire multi-GB volume any time a single file in there changes, since to Dropbox it's just one big file. (Another option is to use something like an OS X sparsebundle -- encrypted data banded across many files -- but God help you if you have two computers reading/writing from that sparsebundle at once.) I've started using SpiderOak and it is quite efficient even though the data is encrypted such that the server admins couldn't see your data even if they wanted too. https://spideroak.com/engineering_matters https://spideroak.com/engineering_matters SpiderOak also offers two-factor auth. (The SpiderOak UI, however, is fairly atrocious.)
  - icebraining 14y ago
    If Dropbox were designed to handle sequentially-numbered blobs of encrypted data, changing one file would require your other devices to download only that file (an encrypted blob of roughly the same size). But they do: store files and name them sequentially ;) I think Encfs is the best solution, since it encrypts each file separately. Just mount the encrypted end over the Dropbox directory and the plaintext end somewhere else, and use it transparently.
  - yafujifide 14y ago
    Only part of a truecrypt volume changes when you make a change to the data within. Since Dropbox intelligently syncs files in parts, only part of a truecrypt volume has to be re-uploaded when something changes -- not the entire multi-GB file. I know because I do exactly this with a 1GB file. It takes about 2 minutes to sync when I unmount the file. Dropbox is not re-uploading all 1GB. However, like the other commenter, I still recommend encfs for most uses.
    - mapgrep 14y ago
      Very interesting, I did not know that.
  - mceachen 14y ago
    If you only have Macs, using an encrypted sparse bundle disk image is pretty simple, and changed files result in a small delta for dropbox to sync. It's built in and you'll be up and running in a couple minutes: http://matthew.mceachen.us/blog/free-easy-encrypted-storage-for-mac-142.html http://matthew.mceachen.us/blog/free-easy-encrypted-storage-...
    - chmars 14y ago
      it is only simple if you always manage not to open such a sparse bundle on another Mac before it has been fully synced after being used on another Mac. Otherwise, you will mess up your sparse bundle sooner or later. A service for syncing and sharing with built-in encryption might therefore me more convenient for most users. Spideroak and Wuala are two examples.
- sliverstorm 14y ago
  The downside, of course, is no differential sync'ing. So, if you make a change to your volume, you must re-upload the entire volume. Worth doing for some files, yes, but still a pain. Per-file encryption would be ideal, but a monstrous pain to implement with TrueCrypt. Dropbox is probably not crazy about widespread encryption because it would eliminate their ability to perform deduplication. Perhaps they could get around this if you had a special encrypted quota. For example, you have 5GB of space and 100MB of encrypted space.
  - deleted 14y ago
    [deleted]
  - Dylan16807 14y ago
    If you only change a few kilobytes, dropbox only has to upload a few kilobytes. I just modified a file in a 64MB truecrypt container and unmounted it. Dropbox took roughly five seconds to sync it. The only real problem with truecrypt in dropbox is that you can't keep it mounted on multiple devices.
    - sliverstorm 14y ago
      What do you know, you're right. I am impressed; I was under the impression that because of the encryption, Dropbox couldn't reliably determine what pieces changed.
      - Dylan16807 14y ago
        Truecrypt is designed to work on a block-by-block basis or else it would be horribly slow at everything. So dropbox's job isn't harder than any arbitrary binary file with a few KB changing. Easier, really, since nothing changes size and shifts the data after it.
    - mikhael 14y ago
      You would also lose easy access to file histories, correct? This is one reason why I'm a fan of SpiderOak -- the index remains encrypted, but file histories are still stored (efficiently).
- chime 14y ago
  Kinda defeats the purpose of DropBox. If you're going to use volume encryption, might as well use Tarsnap or something else to just backup the one large file.
- rdl 14y ago
  The problem is on mobile/console/etc. devices.
- Spooky23 14y ago
  Consider what your goals are with respect to encryption -- allowing the deltas generated by modifying your TrueCrypt volume will almost certainly make it easier for an adversary to break into your encrypted volume.
  - Dylan16807 14y ago
    Are the algorithms used weak to that? I know that deltas will reveal the locations of changes and also let you detect whenever the same sector has the same bytes written to it. What else might be revealed?
irunbackwards 14y ago
You seem like you'd be appreciative of this service: http://getsecretsync.com/ss/ http://getsecretsync.com/ss/
bschlinker 14y ago
Get Boxcryptor.
SCdF 14y ago
Spideroak works pretty well for me as a secure Dropbox replacement :-)

Great, now only if they actually encrypted my files.

matwood 14y ago

Put a truecrypt volume in your DropBox. Why rely on someone else to do the encryption?

mapgrep 14y ago
If Dropbox were designed to handle sequentially-numbered blobs of encrypted data, changing one file would require your other devices to download only that file (an encrypted blob of roughly the same size). With a TrueCrypt volume or other encrypted file solution on top of Dropbox, you have to resync the entire multi-GB volume any time a single file in there changes, since to Dropbox it's just one big file. (Another option is to use something like an OS X sparsebundle -- encrypted data banded across many files -- but God help you if you have two computers reading/writing from that sparsebundle at once.) I've started using SpiderOak and it is quite efficient even though the data is encrypted such that the server admins couldn't see your data even if they wanted too. https://spideroak.com/engineering_matters https://spideroak.com/engineering_matters SpiderOak also offers two-factor auth. (The SpiderOak UI, however, is fairly atrocious.)
- icebraining 14y ago
  If Dropbox were designed to handle sequentially-numbered blobs of encrypted data, changing one file would require your other devices to download only that file (an encrypted blob of roughly the same size). But they do: store files and name them sequentially ;) I think Encfs is the best solution, since it encrypts each file separately. Just mount the encrypted end over the Dropbox directory and the plaintext end somewhere else, and use it transparently.
- yafujifide 14y ago
  Only part of a truecrypt volume changes when you make a change to the data within. Since Dropbox intelligently syncs files in parts, only part of a truecrypt volume has to be re-uploaded when something changes -- not the entire multi-GB file. I know because I do exactly this with a 1GB file. It takes about 2 minutes to sync when I unmount the file. Dropbox is not re-uploading all 1GB. However, like the other commenter, I still recommend encfs for most uses.
  - mapgrep 14y ago
    Very interesting, I did not know that.
- mceachen 14y ago
  If you only have Macs, using an encrypted sparse bundle disk image is pretty simple, and changed files result in a small delta for dropbox to sync. It's built in and you'll be up and running in a couple minutes: http://matthew.mceachen.us/blog/free-easy-encrypted-storage-for-mac-142.html http://matthew.mceachen.us/blog/free-easy-encrypted-storage-...
  - chmars 14y ago
    it is only simple if you always manage not to open such a sparse bundle on another Mac before it has been fully synced after being used on another Mac. Otherwise, you will mess up your sparse bundle sooner or later. A service for syncing and sharing with built-in encryption might therefore me more convenient for most users. Spideroak and Wuala are two examples.
sliverstorm 14y ago
The downside, of course, is no differential sync'ing. So, if you make a change to your volume, you must re-upload the entire volume. Worth doing for some files, yes, but still a pain. Per-file encryption would be ideal, but a monstrous pain to implement with TrueCrypt. Dropbox is probably not crazy about widespread encryption because it would eliminate their ability to perform deduplication. Perhaps they could get around this if you had a special encrypted quota. For example, you have 5GB of space and 100MB of encrypted space.
- deleted 14y ago
  [deleted]
- Dylan16807 14y ago
  If you only change a few kilobytes, dropbox only has to upload a few kilobytes. I just modified a file in a 64MB truecrypt container and unmounted it. Dropbox took roughly five seconds to sync it. The only real problem with truecrypt in dropbox is that you can't keep it mounted on multiple devices.
  - sliverstorm 14y ago
    What do you know, you're right. I am impressed; I was under the impression that because of the encryption, Dropbox couldn't reliably determine what pieces changed.
    - Dylan16807 14y ago
      Truecrypt is designed to work on a block-by-block basis or else it would be horribly slow at everything. So dropbox's job isn't harder than any arbitrary binary file with a few KB changing. Easier, really, since nothing changes size and shifts the data after it.
  - mikhael 14y ago
    You would also lose easy access to file histories, correct? This is one reason why I'm a fan of SpiderOak -- the index remains encrypted, but file histories are still stored (efficiently).
chime 14y ago
Kinda defeats the purpose of DropBox. If you're going to use volume encryption, might as well use Tarsnap or something else to just backup the one large file.
rdl 14y ago
The problem is on mobile/console/etc. devices.
Spooky23 14y ago
Consider what your goals are with respect to encryption -- allowing the deltas generated by modifying your TrueCrypt volume will almost certainly make it easier for an adversary to break into your encrypted volume.
- Dylan16807 14y ago
  Are the algorithms used weak to that? I know that deltas will reveal the locations of changes and also let you detect whenever the same sector has the same bytes written to it. What else might be revealed?

irunbackwards 14y ago

You seem like you'd be appreciative of this service: http://getsecretsync.com/ss/ http://getsecretsync.com/ss/

bschlinker 14y ago

Get Boxcryptor.

SCdF 14y ago

Spideroak works pretty well for me as a secure Dropbox replacement :-)