DESLock+ lets you choose from among three strong standard algorithms.Encryption programs let you control who has access to your files--ideal when you're sharing your PC or working on a laptop that could be lost or stolen. The apps use an algorithm to scramble a file's plain text into encrypted ciphertext. You need a password-protected key--either software or USB-connected hardware--to descramble the files. Lose this password (or the dongle), and unless you've made backups, it's adios data.

I reviewed shipping versions of a trio of encryption programs: DESlock+ 3.2.4 Single User Pack, Namo FileLock 3.10, and T3 Basic Security. Of the three, DESlock+ 3.2.4 earned the highest rating--it's the most robust app, but the hardest to use. Namo FileLock 3.10 flips that equation. T3 Basic Security, designed for laptop use, balances strong encryption with a simple interface.

The DESlock+ 3.2.4 software, although free for personal use, costs $185 with two USB hardware dongles--one for daily work and the other for backing up encryption keys. It permits you to assign and share encryption keys with other DESlock users; and unlike the other two programs, it allows you to choose your algorithm, whether 3DES, AES, or Blowfish (all top-grade options). Right-clicking on a file or folder lets you encrypt it and create e-mailable encrypted file archives. For automatic creation of e-mail attachments, DESlock+ comes with plug-ins for Microsoft Outlook and Lotus Notes.

DESlock+ isn't all that easy to use, so make sure to keep its 110-page printed manual handy. Commands aren't self-explanatory, and you need to immediately configure both of the USB dongles and designate one as a backup in the DESlock control panel. If you don't, you'll be greeted with a pesky backup wizard each time you plug one in.

The $40 FileLock 3.10, on the other hand, is a quick one-window application that lets you drag and drop files and folders into a designated, encrypted area with its own drive volume. Upon installation, you have to create a password and set aside a portion of your hard drive to store your encrypted files. At subsequent launches, FileLock brings up a small orange window with a picture of a safe, which you click on to enter the password for accessing files.

FileLock has no USB hardware option, but it does let you back up your encrypted folder. Namo's packaging doesn't acknowledge that FileLock uses a 96-bit proprietary algorithm as well as a 128-bit SEED algorithm. Namo should disclose the inclusion of its own algorithm, though, because some experts view proprietary algorithms as inferior to highly tested standard algorithms such as 3DES, AES, and Blowfish.

I experienced a few interface bugs with FileLock, too. When I tried to allocate more space to the FileLock folder, the application window sometimes disappeared. Other times, the FileLock window remained on top of other application windows even though I had the 'FileLock always on top' box unchecked. Namo did not respond to PC World's queries about these oddities in time for publication.

T3 Basic Security, intended for use with laptops, comes with a USB hardware key and uses the 128-bit CAST standard algorithm for encryption. T3's unique installation process required that I install the software from a CD, register my full name and contact information, and create a user name and password. This process generated an e-mail that allowed me to download, using Internet Explorer (Firefox support should be available by the time you read this), the Virtual Vault and Parental Control modules included in the $80 Basic Security Suite.

A $100 version adds international laptop theft insurance, and a $130 package includes antivirus, firewall, antispam, and antispyware modules. The T3 software interface includes all of these modules, but the ones you're not paying for are grayed out.

Creating multiple virtual vaults is easy, though T3's interface is rudimentary. With the USB key inserted in the PC, you just specify the size (up to 30GB), the file system (NTFS, FAT32, or FAT), and the name of each vault. Simply drag files and folders into the drive volume. Unlike FileLock and DESlock+, it has no backup feature.

As a laptop user, I liked T3 Basic Security the best. I'd recommend DESlock+ for users who have heavy encryption needs; FileLock is strictly for home use, due to its proprietary encryption.