--list-only and symmetric encryption

[Atom 'Smasher']

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

using "--list-only" to learn more about a symmetrically encrypted file, it 
tells me (something like):
 	gpg: CAST5 encrypted data
 	gpg: encrypted with 1 passphrase

it says it's "encrypted with 1 passphrase"... can it be encrypted with 
multiple passphrases?


         ...atom

  _________________________________________
  PGP key - http://atom.smasher.org/pgp.txt
  762A 3B98 A3C3 96C9 C6B7 582A B88D 52E4 D9F5 7808
  -------------------------------------------------

 	"For every dollar the boss has and didn't work for,
 	 one of us worked for a dollar and didn't get it."
 		-- William 'Big Bill' Haywood
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.3.6 (FreeBSD)
Comment: What is this gibberish?
Comment: http://atom.smasher.org/links/#digital_signatures

iEYEARECAAYFAkDbr5MACgkQnCgLvz19QeM7ugCeJTeyA1x3JARGZy7rTuc6gDiP
tacAoIdSfTFL2LjXCiAGmvUHV8mjl9SV
=r+5T
-----END PGP SIGNATURE-----