wmartin@ALMSA-1.ARPA.UUCP (03/25/87)
Here are a few followups on those items from the RISKS Digest that I
previously submitted to Telecom. (These are from RISKS 4.67.)
Will Martin
(The RISKS moderator has some comments in [square brackets]. I stuck mine
in also in [square brackets] but with asterisks in col. 1 in addition. WM)
******
Date: Tue, 24 Mar 87 12:19:53 est
From: Jerome M Lang <jmlang%water.waterloo.edu@RELAY.CS.NET>
To: RISKS@CSL.SRI.COM
Subject: Who called? (Re: RISKS DIGEST 4.66)
In the last digest mention was made about the possibility of learning the
phone number of the caller. This raises the question of what is done when
the caller has an unlisted phone number (usually for very good reasons).
Jerome M. Lang || jmlang@water.bitnet jmlang@water.uucp
Dept of Applied Math || jmlang%water@waterloo.csnet
U of Waterloo || jmlang%water%waterloo.csnet@csnet-relay.arpa
[Clearly one would have to suppress that information -- under certain
circumstances -- although it is clearly needed for the 911 computers.
This gets into the problem of secure databases and how difficult it can be
to prevent inferences from being drawn if you are going to hide information
selectively. Lots of nice research has been done, but basically this is a
very difficult problem once you take the blinders off. PGN]
*[Myself, I disagree. I feel you lose your right to have your number
*secret as soon as you call someone else. Once you impose on that other
*party (and it doesn't matter if you are calling a residence or a
*business), they have the right to know your number. But note that this
*doesn't mean they know who YOU are, unless they have the facilities for
*looking up a name/address given a number. - WM]
------------------------------
Date: Tue, 24 Mar 87 09:02:16 CST
From: munnari!augean.oz!alex@seismo.CSS.GOV (Alex Dickinson)
To: risks@csl.sri.com
Subject: Car Phone Intercept -- implications of captured data
On Sunday 22nd March an Australian activist group using a radio frequency
scanner intercepted and recorded an unencrypted car phone conversation
between a federal opposition shadow minister and a state opposition leader
(both members of the Australian Liberal Party). The conversation referred to
the Liberal Party federal leader in what has been euphemistically termed
`colourful language' and discussed his intended political demise. The group
released the tape to a Melbourne newspaper that proceeded to publish a
number of juicy excerpts.
Today the federal shadow minister was fired from his party post, and the
chance of an election being called by the Prime Minister to take advantage
of opposition confusion was regarded as having doubled from 15 to 30%.
Federal police are considering whether to press charges under the
Telecommunications Act that broadly covers such interceptions. The fine?
$5000 maximum. Good value for altering the course of the country's politics,
although it's not clear that that was the intent.
Alex Dickinson
------------------------------
Date: Tue, 24 Mar 87 16:41:19 EST
From: Michael Wagner <wagner@gpu.utcs.utoronto>
Subject: Re: Increased Telephone Switching Capabilities
X-To: risks@sri-csl.arpa
I can offer two pieces of information, neither of which answer the questions
completely.
1) the 911 emergency number in Toronto displays the number from which a call
was made. It does this for a wide variety of originating exchanges (but I
don't know if it does it for all exchanges). I have been told, by people
who are more knowledgable about phones than I, that the number is sent on
the same circuit as the phone call. They claim that almost no gymnastics
were required to make this work.
(The phone company also makes a database of phone numbers and addresses
available to the emergency service, so that numbers are quickly turned into
street addresses. That clearly wouldn't be available to the average
business or home. But that is a different matter.)
The implications are that (a) exchanges send the origination phone number
along with the call, and (b) exchanges can relatively trivially send the
information to the customer phone, and (c) the customer phone can decode
the information while the phone is still ringing, and (d) it's not illegal
in Canada for emergency use.
2) The University of Toronto recently switched over to a Centrex III system.
Certain (secretarial) phones can now display the number called and the
number calling. The number calling works only if the call originated within
the centrex exchange. It is not clear whether the restriction is technical
or legal. The implication is that it's not illegal in Canada for calls
originating within an enterprise.
It is clear that, if such a telephone were to become a consumer item, it
would change the whole way we deal with telephones. I could refuse to
answer calls from people I didn't want to speak to right now. In fact, I
would probably program the micro in the telephone with a phone list of
people who were and weren't allowed to disturb me. There would appear to be
many human engineering problems to solve there. And many computer RISKS.
Michael
------------------------------
Date: Mon, 23 Mar 87 12:45:40 PST
From: bnfb@beaver.cs.washington.edu (Bjorn Freeman-Benson)
To: RISKS@CSL.SRI.COM
Subject: Re: Telephone switches
>The issue of automatic callers releasing the phone line is actually
>a people issue rather than a technology issue.
As far as I know it depends on the "office" (telephone company term for
switching equipment) connected to your phone. In the NW US
there are three types: mechanical, ?, and electronic. A mechanical
office will hold the line open as long as the caller has his/her phone off the
hook regardless of the callee's actions. An electronic office will close
the connection as soon as either party hangs up.
>Panic sets in and a feedback loop ensues.
However, I do agree that this can be a problem in any human system.
Bjorn N. Freeman-Benson
******
End of extract from RISKS
[JSol: First of all, the 3 types of switching are Step-By-Step,
crossbar (both of these are mechanical) and Electronic (and digital).
All forms of switching posess a facility to terminate the call within
20 seconds of hang up. Almost all telephone companies will install
this upon request if not already there.]leonard%percival%reed@tektronix.tek.COM.UUCP (03/29/87)
There has been a lot of talk about the 'display calling number" feature in the public Bulletin Board Syystems (BBS's) locally. Most of it was a year or so back. Most sysops would kill to get this feature. The number of would be 'hackers' and other low-life BBS nuisances would be vastly reduced. I saw a msg from a sysop somewhere in the southeastern US who claimed to be particpating in a test of the feature by his local phone co. He seemed quite pleased with it. -- Leonard Erickson ...!tektronix!reed!percival!leonard CIS: [70465,203] ...!tektronix!reed!percival!!bucket!leonard "I used to be a hacker. Now I'm a 'microcomputer specialist'. You know... I'd rather be a hacker."