The default Outlook installation uses 40-bit encryption. If you have an earlier version of Outlook installed using 128-bit encryption, the Windows Installer updates that installation to the most recent 128-bit technology.

An update is available that enables users to upgrade existing 40-bit Outlook 2000 encryption to 128-bit. The update may be downloaded from the following Web address: NOTE: Users do not need to have 128 bit to use the download on the Web site. This update can only be applied to Outlook 2000; it does not work with earlier versions.

128-bit and 40-bit encryption refer to the size of the key used to encrypt the data in the message. 40-bit encryption is not as secure as 128-bit. 128-bit encryption is approximately 309,485,009,821,345,068,724,781,056 times more secure than 40-bit encryption.