anonymous mailboxes

Some time ago I heard about Lucky Green's then-immature scheme for anonymous email boxes, whereby a user can receive email and even a traffic analysis attacker is unable to glean information about who received what when. I forget exactly what ve called vis method... Is there a paper available anyplace? Has the scheme been validated mathematically? Has it been implemented? ::sprokkit:: ______________________________________________________ Get Your Private, Free Email at http://www.hotmail.com