[redblacktree]

I combine dropbox with TrueCrypt for sensitive stuff. For me, that's just digital copies of important documents.

[aasarava]

So are you just syncing entire truecrypt .tc files to Dropbox? Does that work incrementally or does the entire .tc file have to get resent every time you modify a file within?

[d23]

I always assumed it wouldn't work incrementally, but it seems to sync my 200MB tc file too quickly to be uploading the entire thing when I make a small change. Perhaps someone who actually knows something about encryption can speak to this. Does every byte in an encrypted volume change when a piece of data changes? I guess that would be too inefficient to be the case, no?

[dchest]

Yes, only parts of the underlying file are changed. TrueCrypt uses XTS mode of operation (https://en.wikipedia.org/wiki/Disk_encryption_theory, http://www.truecrypt.org/docs/modes-of-operation).

[redblacktree]

The entire file may be resent, but practically it works just fine for me. The total volume is only 250mb and it is updated infrequently.

[Afforess]

The entire file is resent.

[sigil]

No, only changed blocks are resent. The scattering effect of Truecrypt encryption plus the relatively large blocksize does amplify the number of changed blocks somewhat.

Previous investigation and results:

http://news.ycombinator.com/item?id=2546626

[BHSPitMonkey]

Citation? Other comments are offering conflicting reports.

[philip1209]

Yes - in my dropbox public folder, I keep a truecrypt bucket with scans of everything in my wallet, should I lose it.