The RISKS Digest
Volume 2 Issue 10

Wednesday, 12th February 1986

Forum on Risks to the Public in Computers and Related Systems

ACM Committee on Computers and Public Policy, Peter G. Neumann, moderator

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o Computerized aircraft collision avoidance
Peter G. Neumann
o Computerized Feedback and the Stock Market
Eric Nickell
o Analyst Changes City Treasurer's Computer Code
Mike McLaughlin
o Plutonium on the Space Shuttle
Tom Slone
o Request to RISKS Readers from COMPASS 86 (COMPuter ASSurance)
Al Friend
o Info on RISKS (comp.risks)

Computerized aircraft collision avoidance

Peter G. Neumann <Neumann@SRI-CSL.ARPA>
Wed 12 Feb 86 10:46:35-PST
As noted on various previous occasions, it is always nice to report
computer-related successes in avoiding risks, but they seem to get scant
notice.  Perhaps some of you can keep your eyes open.

I had a phone report last night of a TV news item in Washington DC, relating
to a computerized aircraft collision-avoidance system that succeeded in
preventing what otherwise would have been a midair collision yesterday.  Can
anyone provide details?


Computerized Feedback and the Stock Market

Mon, 10 Feb 86 08:31:17 PST
Martin Minow's note about the effect that computerized stock traders can
have on the market brings up an interesting general situation.

Any self-correcting system which has a delay in the feedback loop (as
opposed to something like a spring, where the feedback is instantaneous)
can fail to correct itself if it is pushed too hard during a single
feedback period.  Further, if the forces acting on the system are
themselves made a function of the system, there is the possibility of
increasingly amplified oscillation until the system breaks down at some

The stock market is a case in point.  Stock prices drift according to
the buying and selling of the stock.  But in the case Martin Minow
cites, I am guessing that the computers were able to deluge the system
with sell orders before the price could adjust itself.

The delay in price adjustment was not a problem until we had computers
capable of swamping it with orders.  Thus we may be introducing
computers into environments where slowness provides some degree of
stability to a process.  Speed itself has its dangers.

Eric Nickell    Nickell.pasa@Xerox.xcom

Analyst Changes City Treasurer's Computer Code

Mike McLaughlin <mikemcl@nrl-csr>
Mon, 10 Feb 86 10:14:01 est
Deputy Mayor's Employe Changed Computer
by Peter Perl, Washington Post Staff Writer

Plutonium on the Space Shuttle

415)486-5954] Tue, 11 Feb 86 09:49:49 pst
Recent Freedom Of Information Act (FOIA) information has revealed that NASA
officials considered the possibility of a Space Shuttle exploding to be so
remote that the dangers of carrying tens of pounds of Plutonium aboard was
not given much thought.  Plans are apparently still in the works to launch
these Plutonium driven space probes starting in May of this year.  The
manufacturer of these probes has claimed that the Plutonium element would
have survived the Challenger explosion as material of similar strength was
recovered from the debris.

Request to RISKS Readers from COMPASS 86 (COMPuter ASSurance)

Al Friend <friend@nrl-csr>
Tue, 11 Feb 86 10:41:50 est
                            WE NEED YOUR HELP

TO:    The readers of the RISKS FORUM
FROM:  Program Committee COMPASS 86

1.  We need an estimate of attendees and authors at a conference we are
    planning.  Also, we need input in terms of ideas and events for it.

2.  The conference is COMPASS 86, which stands for COMPuter ASSurance.

    This conference is all about the things we are discussing in this forum.
    The security and safety of processes rather than data banks, or
    communication links.  We have in mind not only weapons and defense type
    systems, but medical systems, tranportation systems, and the multitude of
    computer controlled systems that touch our everyday lives.

    Dave Parnas will be the keynote speaker.

    There will be a series of panel discussions, which will address everything
    from SDI to the application of AI.

    Papers will be reviewed by computer and software scientists working in the
    areas of safety and security from the University of California, SRI,
    and the Naval Research Laboratory.

    The idea is to encourage new ideas, new applications of neglected ideas
    and promote useful interactions.

3.  The conference specifics are:

    DATE:  7-11 July 1986
    PLACE:  The George Washington University, Wash., DC
    HONORARY CHAIRMAN (prospective):  Ruth Davis, former Assistant to
                                      Deputy Undersecretary of Defense
                                      for Research and Advanced Technology
    GENERAL CHAIRMAN (prospective):   H.O. LUBBES, Space and Naval Warfare
                                      Systems Command (lubbes@nrl-csr)
    SPONSOR:                          IEEE Washington Section

4.  It would help us if the readers of this forum could give us some feedback
    on the number of people likely to attend and the number of people likely
    to submit papers.  Also, we would like to incorporate any special events
    that people would like to see into it.  The important dates are:

        March 31 --- Abstracts Due
        April 30 --- Authors Notified
        May 30   --- Camera Ready Manuscripts Due

    The call for papers is in the February issue of IEEE Computer.  Also, a
    version of it ran a little while back in this forum.

          [I won't comment on the risks of running the first conference of
           its kind!  Good luck.  PGN]

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