With TrueCrypt For Mac No data stored on an on-the-fly-encrypted volume (data storage device).  On-the-fly encryption means the data is loaded or decrypted right before it is a software system for establishing and maintaining an encrypted volume can be read (decrypted) without using the correct password/keyfile(s) or correct encryption keys. TrueCrypt For Mac is encrypted (e.g., file names, folder names, contents of every file, free space, meta data, etc). Entire file system is automatically encrypted or saved, without any user intervention.

License : Freeware

Download TrueCrypt  for Mac