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Arise, you have nothing to lose but your barbed wire fences!

1995-01-27 - Re: CERT statement

Header Data

From: “Perry E. Metzger” <perry@imsi.com>
To: Thomas Grant Edwards <tedwards@src.umd.edu>
Message Hash: 620d27042192c1b2f94bb65b613dc15b70c7ea89e18650a39e79994e70089dd0
Message ID: <9501271852.AA19504@snark.imsi.com>
Reply To: <Pine.SUN.3.91.950127134421.22225A-100000@thrash.src.umd.edu>
UTC Datetime: 1995-01-27 18:53:30 UTC
Raw Date: Fri, 27 Jan 95 10:53:30 PST

Raw message

From: "Perry E. Metzger" <perry@imsi.com>
Date: Fri, 27 Jan 95 10:53:30 PST
To: Thomas Grant Edwards <tedwards@src.umd.edu>
Subject: Re: CERT statement
In-Reply-To: <Pine.SUN.3.91.950127134421.22225A-100000@thrash.src.umd.edu>
Message-ID: <9501271852.AA19504@snark.imsi.com>
MIME-Version: 1.0
Content-Type: text/plain



Thomas Grant Edwards says:
> On Thu, 26 Jan 1995, Perry E. Metzger wrote:
> 
> > Kerberos per se isn't sufficient to defend against session hijacking
> > attacks, you know. The situation in question is really insidious and
> > requires packet-by-packet cryptographic authentication.
> 
> Do you really need to authenticate every packet?  Isn't it enough to 
> authenticate the party and perform a secure key exchange, then depend on 
> the encryption (+ message authentication code for block ciphers) ?

If things are merely encrypted, an attacker can garble them without
being caught -- I can "decrypt" random numbers into other random
numbers if I want.  Think of an attacker trying to sabotage the
transfer of a binary file and you'll see why you need authentication.

Perry

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