Path: utzoo!attcan!uunet!cs.utexas.edu!wuarchive!mit-eddie!bloom-beacon!bu.edu!buit13!kwe
From: kwe@buit13.bu.edu (Kent England)
Newsgroups: comp.dcom.lans
Subject: Re: Motorola wireless lan?
Message-ID: <67319@bu.edu.bu.edu>
Date: 29 Oct 90 17:43:22 GMT
References: <418@bartal.CRLABS.COM> <67070@bu.edu.bu.edu> <1990Oct26.155442.27053@zoo.toronto.edu>
Sender: news@bu.edu.bu.edu
Reply-To: kwe@buit13.bu.edu (Kent England)
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Organization: Boston U. Information Technology
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In article <1990Oct26.155442.27053@zoo.toronto.edu> 
 henry@zoo.toronto.edu (Henry Spencer) writes:
>In article <67070@bu.edu.bu.edu> kwe@buit13.bu.edu (Kent England) writes:
>>... The headache you get, of
>>course, is you will have to look to find out who is using your radio
>>LAN...
>
>Including that van parked out in front with your competitor's name on it!
>Nobody who has any concern for privacy or confidentiality should even be
>considering wireless LANs unless they plan to encrypt all traffic.
>-- 

	Henry, that's a good point and I failed to note that spread
spectrum has a certain degree of security that it gains from the
pseudo-random encoding that is used to spread the spectrum.  An
observation of a deterministic pseudo-random number sequence does not
help much in determining the algorithm and seed used to generate the
PSN sequence.  Without the PSN sequence, the actual data cannot be
extracted from the spread spectrum digital sequence.

	Spreading the spectrum makes the signal hard to jam and
pseudo-random encoding sequences make the actual data difficult to
decipher, both features initially attracted the military development. 

	A receiver has to have the pseudo-random number algorithm
(easy), seed (hard), and a good idea of the time (a little tricky) to
decipher a spread spectrum signal.  You might find spread spectrum
technology to be sufficiently secure for your purposes, although I
would recommend Kerberos or other robust authentication mechanism for
access to your wireless LAN and for distributing information like seed
number changes to your authorized users.

	Thanks for pointing out this problem area.  It is something
that potential users will have to satisfy themselves about.

	--Kent