Which encryption method is best for me?

Mozy Backup encrypts the files on your computer before they are sent over the Internet to the Mozy cloud. Your files remain encrypted when stored in the Mozy cloud and can only be read if you have both the encryption key and the means to read the encrypted file.
When you install Mozy software, you will able to select the type of encryption method you want to use for your backups. That encryption is permanently associated with all files sent to the Mozy cloud from that computer, so we recommend you to read very carefully the information below.

You can change the encryption key type after you install the Mozy Backup software. Doing this requires you to uninstall the Mozy software, delete that computer from your account, then reinstall the software, choosing the different encryption key at that time. The Mozy software then uploads all your files again to ensure that the stored files match the current encryption key.

Which encryption methods are available?

You will be able to choose between 448-bit Blowfish encryption (selected by default) or Personal Key (using the Advanced Encryption Standard (AES)).

With 488-bit Blowfish encryption, Mozy separately creates and store the encryption key for you. This is the least complicated, imposing no restrictions on any Mozy features.

Personal Key provides a higher level of security; you will be asked to create your own encryption key passphrase. When you download and restore files, you must supply the key you've created to decrypt those files. However if you lose or forget the Personal Key passphrase, neither BT nor Mozy will be able to decrypt your data.

More details on both encryption methods can be found here.