KeePass gets good comments. (IIRC there's a Linux version, I don't know how kludge-y.) Bruce Schneier (security guru / blogger) uses something similar (though

KeePass gets good comments. (IIRC there's a Linux version, I don't know how kludge-y.) Bruce Schneier (security guru / blogger) uses something similar (though I don't know that he tosses the data files out onto shared storage). In the past, some people have commented about placing a TrueCrypt volume-as-file on DropBox. Apparently performance and storage consumption were, per them, not as bad as one might think. (Think about the potential implications of the version history that DropBox provides by default.) There are some other programs, including some text editors, notepad type editors, and "personal wiki" programs that offer to save to an AES or Blowfish encrypted format. I imagine the correctness/robustness of their implementations may vary. Finally, if you just want to encrypt a file already disk, the well regarded archive program 7zip (and others) includes an AES encryption/decryption implementation. I don't know how its implementation is regarded. Note that, under DropBox, this won't eliminate prior, unencrypted versions that are saved by its versioning system. Also, GPG and PGP are always around. If you encrypt a pre-existing file, outside of the DropBox context it's a good idea to encrypt to a fresh copy, then securely wipe the original. EDIT: Depending upon what is being used for encryption, the DropBox versioning might itself represent a weakness. I'm not qualified to speak to such topics -- just imagining.