Re: [sc] Qantas Flight 72 Final Report



Re: [sc] Qantas Flight 72 Final Report

From: Peter Bernard Ladkin <ladkin_at_xxxxxx>
Date: Fri, 23 Dec 2011 12:59:23 +0100
Message-ID: <4EF46D1B.6090707@xxxxxx>
On 12/23/11 11:07 AM, Thierry.Coq@xxxxxx wrote:
> Isn't this a Byzantine General problem?

Yes. A one-failure instance.

> In the absence of other information on the validity of the inputs, doesn't this need (at least) 4 values to be able to discount one properly?

Maybe. To go with the majority reading in cases in which there are at least three sensors and at 
most one failure, and no authentication, in all possible cases, this needs at least four devices, 
yes. And a hairy algorithm.

If one uses a weak form of digital signature, you can do it with three.

This all from the original papers 
http://research.microsoft.com/en-us/um/people/lamport/pubs/pubs.html#reaching and 
http://research.microsoft.com/en-us/um/people/lamport/pubs/pubs.html#byz

PBL

Peter Bernard Ladkin, Professor of Computer Networks and Distributed Systems,
Faculty of Technology, University of Bielefeld, 33594 Bielefeld, Germany
Tel+msg +49 (0)521 880 7319  www.rvs.uni-bielefeld.de
Received on Fri 23 Dec 2011 - 11:59:30 GMT