from
The Free On-line Dictionary of Computing (8 July 2008)
passphrase
<operating system> A string of words and characters that you
type in to authenticate yourself. Passphrases differ from
passwords only in length. Passwords are usually short - six
to ten characters. Passphrases are usually much longer - up
to 100 characters or more. Their greater length makes
passphrases more secure. Modern passphrases were invented by
Sigmund N. Porter in 1982.
Phil Zimmermann's popular encryption program {PGP}, for
example, requires you to make up a passphrase that you then
must enter whenever you sign or decrypt messages.
(http://world.std.com/~reinhold/diceware.page.html).
(1996-12-21)