著名的加密软件的应用于电子邮件中

				/*
				 * pass.h -- Information about PGP passphrases
				 *
				 * Copyright (C) 1997 Pretty Good Privacy, Inc.  All rights reserved.
				 *
				 * Brett A. Thomas (quark@baz.com, bat@pgp.com)
				 *
				 * $Id: pass.h,v 1.1.2.2 1997/06/07 09:49:10 mhw Exp $
				 */
				
				#define PASSLEN 256