Path: utzoo!utgpu!watserv1!watmath!att!cbnews!military
From: jeff@aplcomm.jhuapl.edu (JEFF NANIS )
Newsgroups: sci.military
Subject: Re: Time-lapse PALs on nuclear attack subs
Summary: Can we end this discussion?
Keywords: LF, ELF, VLF
Message-ID: <15586@cbnews.ATT.COM>
Date: 14 Apr 90 04:11:39 GMT
References: <15509@cbnews.ATT.COM>
Sender: military@cbnews.ATT.COM
Organization: JHU/APL, Laurel, MD
Lines: 34
Approved: military@att.att.com



From: jeff@aplcomm.jhuapl.edu (JEFF NANIS )

	I would like to try and resolve this thread. There _is_ a bottom
line (or lines):
	1) SSBNs aren't going to go near the surface to receive messages
	on anything like a regular basis
	2) The laws of physics (remember, this is *sci*.military) limit
	the data rate of those LF and lower frequencies that can penetrate
	water to a significant depth. This in turn means that a code of the
	complexity required to enable a PAL (assuming modern encryption 
	algorithms - I have no official knowledge of PALs, only academic
	understanding of encryption) could not be transmitted over such
	links in an *operationally* meaningful time frame.
	3) Just because something is technically feasible does not mean
	that it has any operational utility.

	As was said before:
> Unfortunately for you, anyone with knows enough on this topic to
> have an informed opinion can't say a word about it.
	Please, he's right. This problem has been thought through quite
extensively by many people. There are potential alternatives being assessed.
'Nuff said.

[mod.note:  You're correct, of course; but a rigorous application of this
standard would eliminate most of the topics in this group.  I have no
objection to speculative postings (guesswork, if you insist 8-) of
this sort.  It's part of why we're here.  - Bill ]

--
Jeff Nanis			"You can't send me out there,		
jeff@aplcomm.jhuapl.edu 	 I'm an analyst, not a field agent!"
	Not an official opinion which might get me put in jail.