Alas, for the Mac users out there, there is only one free solution that I have been able to find. The Disk Utility application that ships with all Macintosh computers has the ability to create encrypted disk images. These images are only readable on Mac computers and are not portable to Windows or Linux.
The encrypted DMG format only allows for one encryption mechanism – AES-128. It is not my algorithm of choice. I would prefer to have the capability of using AES-256, and even an option to select a different encryptions such as TwoFish, Blowfish or Serpent. I would also like the ability to select different hash algorithms for the keys. I am unaware of the hash format used for these virtual drives. It would be nice if Apple would provide a selection from the most current hash systems of RIPEMD-160 and Whirlpool.
The solution that I currently use is to create an 80GB DMG on a removable 100GB G-Drive. For added security, the entire disk is formatted as a Mac drive. This renders it unreadable on all but Macintosh computers. It is not as secure as I would like it to be, nor as portable. But I suppose that some sacrifices are necessary in order to use my Mac as my primary machine.
Apple is also lacking in a method to provide whole disk encryption. The FileVault feature only encrypts the user directories on a user-by-user basis. The ability to encrypt the entire contents of the drive is becoming a requirement. I hope that Apple is considering this in Leopard. Failure to provide this feature will further limit Macs acceptance as a viable alternative in the marketplace. With the new security mandates for government computers, it will prevent it from being used in both the government and corporate arenas.