CryptSync

CryptSync synchronizes multiple folders with each other, keeping them up-to-date. One folder of each pair is kept encrypted. The synchronization works both ways: a change in one folder gets synchronized to the other folder. If a file is added or modified in the unencrypted folder, it gets encrypted. If a file is added or modified in the encrypted folder, it gets decrypted to the other folder. This is best used together with cloud storage tools like SkyDrive, DropBox or Google Drive.