The RISKS Digest
Volume 8 Issue 85

Wednesday, 28th June 1989

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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Air Force satellite positioning system cracked
Dave Curry
Loose wire caused Clapham train crash
Jon Jacky
London firms reportedly offer amnesty to ``hacker thieves''
Ken Berkun via Jon Jacky
Re: Microcomputers in the operating theater
Jon Jacky
Diomidis Spinellis
Don't celebrate big tax refund too quickly
David Sherman
Reading meters and gauges by robot in nuclear power plants
Robert Cooper
Info on RISKS (comp.risks)

Air Force satellite positioning system cracked

Wed, 21 Jun 89 22:43:43 -0700
Taken from the San Jose Mercury News, 6/21/89 (from the Kansas City Star):

Teen hacker hits satellite guide system

  A 14-year-old Prarie Village, Kan., boy, using a small home computer,
cracked an Air Force satellite-positioning system and browsed the confidential
files of at least 200 companies, officials say.
  The teen-ager, a computer hacker since the age of 8, apparently did not dam-
age the computer systems he easily entered during the past six months.  He
hoped to use his know-how to persuade the companies to hire him as a computer
security consultant, police said.
  At least two military investigators and representatives of several companies,
including Hewlett-Packard Co. of Palo Alto, showed up at a meeting this month
in Johnson County to try to find out how he did it.
  Dialing unauthorized long-distance access codes, authorities say, the teen-
ager linked his Apple computer with systems throughout the country.  He spec-
ialized in cracking the H-P 3000, a Hewlett-Packard minicomputer widely used
by businesses and the federal government.
  At one point, authorities say, he gained access to an unclassified Air Force
computer system.

[Other than in the first paragraph, there's no more mention of what, if
 anything, the kid did to the satellite positioning system.  The comment that
 he was hoping to be hired seems intriguing to me; I wonder if there's now a
 wave of "interview by cracking" starting up? --Dave]

Loose wire caused Clapham train crash

23 Jun 1989 11:59:16 EST
Here are excerpts from IEEE INSTITUTE, May 1989, p. 4:

``British train accidents signal systemic problems'' by Fred Guterl and
Erin E. Murphy

... Sloppy installation caused (a) recent fatal train accident..., according
to Britrail, the state-run railway system ...  

On Dec. 12 at the busy Clapham junction in south London, ... one commuter
train plowed into the back of another, killing 35 and injuring almost 100.
... In that accident, according to British Rail, the evidence found so far
points to an installation error made a few years ago, when British Rail
replaced the older electromagnetic switches in its signalling system at
Clapham.  ... during this process an equipment room wire from an old switch
was not properly removed and came into contact with the new electromagnetic
signaling system.

The signaling system regulates the movement of a train from one section of
track to another. ... The presence of current indicates both that the next
section of track is unoccupied and what the next signal's setting is. ...  At
Clapham, the loose wire directly operated the signal, overriding the checks in
the system and causing the signal to turn green.  The signaling system was
thought to be fail-safe because a short circuit would simply cause a red
light. ...

The worker who has taken responsibility for leaving the wire loose testified
in the inquiry that on that day he had worked more than 12 hours with only
a 5-minute break ...

- Jon Jacky, University of Washington

London firms reportedly offer amnesty to ``hacker thieves''

<JON.JACKY@GAFFER.RAD.WASHINGTON.EDU [Originally from Ken Berkum}>
23 Jun 1989 12:09:06 EST
  [This comes to me from a friend who lives in Hong Kong.  - Jon Jacky]

From:  (Ken Berkun)

Reported in the June 12, 1989 South China Morning Post, apparently 
reprinted from the London Times, retyped by me, without 

Headline: "Worried firms pay hush money to 'hacker' thieves"

By Richard Caseby

Firms in the City of London are buying the silence of hackers who 
break into their computers and steal millions of pounds.

At least six London firms have signed agreements with criminals, 
offering them amnesties if they return part of the money.  The firms 
fear that if they prosecute they will lose business when customers 
learn that their computer security is flawed.

In several of the case the losses exceeded 1 million  pounds but only 
a tenth of the total was returned.

The Computer Industry Research Unit (CIRU) which uncovered the 
deals and which is advising the Department of Trade and Industry in 
data security, believes the practice of offering amnesties is 

"Companies who feel vulnerable are running scared by agreeing to 
these immoral deals.  Their selfishness is storing up serious problems 
for everyone else," said Peter Nancarrow, a senior consultant.

Police have warned that deals struck with criminals could possibly 
lead to an employer being prosecuted for perverting the course of 

Detective Inspector John Austin, of Scotland Yard's computer fraud 
squad, said: "Employers could find themselves in very deep water by 
such strenuous efforts to protect the credibility of their image."

Legal experts say the firms are mking use of section five of the 
Criminal Law Act 1967 which allows them to keep silent on crimes 
and privately agree on compensation.  However, an employer 
becomes a witness to the offence by taking evidence from a criminal 
when the deal is drawn up.

Hackers steal by electronically transferring funds or by programming 
a computer to round off all transactions by a tiny amount and 
diverting the money to a separate account.

In one case, an assistant programmer at a merchant bank diverted 8 
million pounds to a Swiss bank account and then gave back 7 million 
in return for a non-disclosure agreement portecting him against 

Such thefts have spread alarm throughout the City, with consultants 
offering to penetrate the computer networks of banks and finance 
houses to pinpoint loopholes before a hacker does.

The biggest contracts cost up to 50,000 pounds and can involve a 
four month investigation in which every weakness is explored.

Detectives have found that computer security at many City 
institutions is riddled with loopholes.  A City of London police 
operation, codenamed Comcheck, revealed wide spread weaknesses.  
Firms were asked to track the number of unauthorized logons over 
Easter bank holiday.

Some companies unable to tell whether hackers had penetrated their 
network, while others lacked any security defences.

In addition to theft, companies are vulnerable to blackmail.  Hackers 
can threaton to sabotage computers by inserting "viruses" and "logic 
bombs" - rogue programs which can paralyse a system.

This type of threat has prompted the offer of a new insurance policy 
underwritten by Lloyd's which specifically covers viruses and other 
computer catastrophes.

Re: Microcomputers in the operating theater

23 Jun 1989 13:01:44 EST
There are computer-controlled drug infusion devices on the market; they
are definitely not hobbyist items.  IVAC Corporation of San Diego has made
several presentations at technical meetings recently about a new product
of theirs called the Titrator (registered trademark) Sodium Nitroprusside
Closed Loop Module, which began development in 1981 and was finally approved
by the FDA in December, 1987.  

The FDA began regulating medical device software in 1987.  IVAC believes
its device was the first to be reviewed by the FDA under the new regulations.
Two papers about their experience appear in PROCEEDINGS ON THE ENGINEERING
OF COMPUTER-BASED MEDICAL SYSTEMS, June 8-10, 1988, Minneapolis, Minnesota,
published by the IEEE Computer Society: ``The travail involved in getting
FDA approval --- an overview of what it took to get FDA approval of a medical
device with computer technology (a recent experience)'' by Albert Paul,
pps. 28--29, and ``Failsafe design of closed loop systems'' by Alvis J.
Somerville, pps. 23--27.

- Jonathan Jacky, University of Washington

Re: Microcomputers in the operating theatre

Diomidis Spinellis <diomidis@ecrcvax.UUCP>
Thu, 22 Jun 89 10:37:41 +0200
Keith Emanuel, brings up the question of responsibility in the case of
a microcomputer malfunction.  I remember that National Semiconductor
data sheets used to have a warning to the effect that the component
described should not be used on any life critical application without
prior written permission from the company.  They defined a life
critical application as one whose malfunction or failure to operate
could cause human deaths or injury.  I have not seen such a warning in
data sheets of other manufacturers, so it is probable that this
problem has a precise legal answer.

Diomidis Spinellis, European Computer Industry Research Centre (ECRC).

Don't celebrate big tax refund too quickly

David Sherman <>
Tue, 27 Jun 89 14:48:07 EDT
Toronto Star, June 27, 1989, page B3:

About 6,000 people across Canada have received extra-large refunds after filing
their 1988 income tax returns, and must return the excess.  Clyde King,
spokesman for Revenue Canada's Toronto office, said yesterday the people
affected pay quarterly tax instalments.  These taxpayers, the self-employed and
some retired people, must pay the instalments because they're not subject to
withholding at source on the bulk of their income.  King said that in some
cases Revenue Canada's computer in Ottawa added the first-quarter 1989 tax
instalment to the 1988 refund due, resulting in the excessive refund.

Though about 70,000 people were affected, the error was caught in all but about
6,000 cases before the cheques were sent.  In many cases, taxpayers have
contacted Revenue Canada and sent back the excess.  Eventually the others will
be sent letters of explanation and asked for the return of the money."

[Comment 1: I like the "Revenue Canada's computer added" part.
 People don't create bugs, computers create bugs.]

[Comment 2: one hopes that as well as fixing the bug, they have
 correctly fixed the accounts of people whose 1989 instalments
 may not have been credited properly as of the date due...]

David Sherman, Tax Lawyer, Toronto

Reading meters and gauges by robot in nuclear power plants.

Robert Cooper <>
28 Jun 89 21:16:31 GMT
The June issue of IEEE Computer Magazine contains an article on a robot
vision system which reads analogue and digital meters, lights, and
determines valve, slider and switch positions:

        "A Vision System for Robotic Inspection and Manipulation"
        M. Trivedi, C. Chen, and S. Marapane
        Computer Magazine, June 1989, p. 91.

<The authors envisage a system such as their's being used to inspect and
monitor nuclear power plants: 

        "Although most of our findings relate to a broad class of
        industrial automation tasks, the specific operational environment 
        we considered was a nuclear power plant, where robotic inspection
        offers the potential for reduced radiation exposure to personnel
        and lower plant operating costs."

However the authors, who are funded by the Department of Energy, do not
discuss the risks of relying on such technology in critical applications
such as nuclear power plants. The ONLY allusion to any possible misgivings
people might have to this technology is:

        "These tasks need not be performed totally autonomously; a human
         observer can interpret images acquired by staionary cameras or
         those mounted on robots."

There would appear to be several, more robust, more easily validated
alternatives to this technology. In particular, using a robot vision system
to read an LCD display seems to be a rather expensive and error prone
implementation of a wire!

I feel that anyone proposing a software system for use in critical
applications must discuss the risks involved. And an article in a broad
readership professional magazine such a Computer would be the ideal place.

                              — Robert Cooper (

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