passphrase

    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.

   Modern passphrases were invented by Sigmund N. Porter in 1982.

   Their greater length makes passphrases more secure.

   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)