Encryption keys require a pass phrase, which is similar to a password. Pass phrases are usually longer than passwords and are comprised of several words or groups of text. A good pass phrase is between eight and 128 characters. The minimum number of characters for 128-bit AES encryption is eight. The minimum number of characters for 256-bit AES encryption is 16. Symantec recommends that you use more than the minimum number of characters.
A pass phrase can include only printable ASCII characters, which are characters 32 through 126. ASCII character 32 is the space character, which is entered using the space bar on the keyboard. ASCII characters 33 through 126 include the following: