CenturionSoft was originally invited to participate in our review. After we looked at their software, it became apparent that it wasn't fair to include the company, because it provides desktop encryption. However, its software is quite good, so we've included a brief summary of what it offers.

Its product, CenturionMail 3.0, installs locally on each workstation that needs encryption. It uses one encryption scheme, the AES cipher with a 256-bit key. This is symmetric encryption; that is, you must supply a passphrase to use for encryption and decryption. The user needs to communicate this password to the recipient in some secure fashion ahead of time. Or a user can employ the "hint" function as a password reminder.

While it can work with any e-mail system, it has a snap-in for Microsoft's Outlook. If you click the padlock icon before you hit send, the program will load the CenturionMail client to encrypt the message before it goes. It takes the text from the message and encrypts it into a file. The original body of the message is replaced with a standard message that tells the recipient that the attachment is an encrypted file, which they need to save locally and launch. The attachment can have an extension of .zip, .exe or .cab. Because some e-mail systems block attachments with these extensions, you can also specify a custom extension, which defaults to .cef.

Regardless of what it is named, you must save it locally, rename it to .exe, which tells Windows it is an executable file, and then open it. You will be asked for the password, with the hint displayed, if one has been specified.

It works well, in that the recipient needs no encryption technology to receive an encrypted e-mail. The disadvantages are that recipients must run Windows to open the executable file. Further, there is no way for the recipient to reply to the message in a secure way.

There is also an administrator toolkit, which allows your IT group to lock certain aspects of the program. It allows for limited branding of the messages, including a logo and company URL. Further, you can set a default location for copies of secure messages to be stored for later use.

CenturionMail includes utilities that allow for local file encryption. This is handy for traveling users with laptops. They may want to encrypt sensitive data on their desktops in case their laptop is stolen.