From: pmetzger@shearson.com (Perry E. Metzger)
Date: Thu, 4 Feb 93 12:59:35 PST
To: cypherpunks@toad.com
Subject: `Sunday Times' article on GSM changes
Message-ID: <9302042024.AA09970@maggie.shearson.com>
MIME-Version: 1.0
Content-Type: text/plain


Thought I'd forward this.


----- Begin Included Message -----

>From libernet-request@dartmouth.edu Wed Feb  3 18:51:12 1993
Resent-Message-Id: <4fQ2vaH0BwxI41u9ED@transarc.com>
Resent-Date: Wed,  3 Feb 1993 15:45:26 -0500 (EST)
Resent-From: Lyle_Seaman@transarc.com
Resent-To: libernet@dartmouth.edu
X-Andrew-Widereply: netnews.sci.crypt
Newsgroups: sci.crypt
Path: andrew.cmu.edu!bb3.andrew.cmu.edu!news.sei.cmu.edu!cis.ohio-state.edu!zaphod.mps.ohio-state.edu!howland.reston.ans.net!usenet.ins.cwru.edu!agate!doc.ic.ac.uk!rhbnc!andy
From: andy@csqx.cs.rhbnc.ac.uk
Subject: `Sunday Times' article on GSM changes
Organization: RHBNC
Date: Tue, 2 Feb 1993 16:07:01 GMT
Lines: 94
Sender: libernet-request@dartmouth.edu
X-Mailing-List: libernet@Dartmouth.EDU
Content-Length: 4387

  Having finally managed to track down a copy of last Sunday's `Sunday
Times', here is the text of the article describing changes to the GSM
mobile communications standard.

  The A5 `scrambling code' refered to in the article is the stream cipher
between the mobile and base stations, which uses a 64-bit key derived from
an initial authentication exchange.  Whilst it's not exactly secret, as
many people involved with developing GSM need to know the details, it is
covered by non-disclosure agreements.

  `New Scientist' also have an article on GSM in this week's issue.

andy
--

`The Sunday Times',  31 January 1993.   Main section, p. 12.  (Home News)

SPYMASTERS ORDER REDESIGN OF `TOO SECURE' MOBILE PHONES  by Christopher Lloyd

[Cartoon of a ridiculous mobile handset with various antennaea and dishes
protruding.  It is being held by a dismayed, purple-suited, man whilst a
sign reads: "New! GCHQ-approved mobile phone".]

  The next generation of mobile telephones has proved so secure against
tapping that it is to be made less safe on the advice of the intelligence
services.  The phones, based on coded digital technology, will have their
technology modified so that spies can continue to eavesdrop on private
conversations.

  The changes, ordered by a European Community (EC) telecommunications
committee in Brussels, are being made at the insistance of European
governments, including Britain's.  They fear that surveillance operations
against drug barons, the criminal underworld and foreign powers could be
undermined.

  Digital mobiles phones, based on a system called GSM, are already
replacing standard analogue networks across the world. They are equipped
with a sophisticated scrambling code called A5, offering protection from
interception equivelant to many military systems.

  It is this code that is to be replaced by one called A5X, to allow
undercover eavesdropping to continue.

  Last week a Department of Trade and Industry spokesman confirmed changes
were being introduced to make it easier for security agencies - ranging
from GCHQ, the British government's listening post near Cheltenham, to the
FBI in America - to eavesdrop.

  "Alternatice coding is being developed for the reasons you have
outlined," he said.  "There is a general desire for this among the
governments of Europe."

  The department, which issues export licenses for the phones, is
particularly concerned that the original A5 technology should not be sold
to countries that may adapt it for military applications. 

  In America, the FBI has voiced similar concern.  Nestor Michnyak,
spokesman for the FBI headquarters in Washington, said that digital
technology was advancing so fast that counter-surveillance was in danger
of being undermined.

  "We are trying to get companies and manufacturers to work with us to
allow us to maintain the surveillance operations we have undertaken since
the late 1960s," he said.  "All we are asking is to be able to continue to
do what we are currently doing and we want the same access we are having
now."

  Manufacturers of GSM mobile phones will be forced to adapt products to
work with the new codes.  Motorola, one of the leading makers of the
digital mobile handsets, complained that costs may rise as a result.

  "We are flying blind here," said Larry Conlee, the assistant general
manager of Motorola's European cellular division.  "The GSM system has
ended up more secure than it should have been for the commercial market
and now we're trying to recover from it."

  Vodafone, Britain's largest analogue mobile phone company, which has
already installed 250 GSM base stations covering 50% of the UK population,
said its network will need to be adapted to accept the new codes.

  "Government authorities have made it known that they don't want this
high level of encoding," said Mike Caldwell, the spokesman for Vodafone.

  Caldwell said the problem with the original system was that it would
take security services weeks rather than minutes to decode the
conversations they wanted to bug.  Despite the changes, it will be still
virtually impossible for any amateur eavesdropper to intercept calls made
on the digital mobile phones.

-- 
Andy Thomas
Information Security Group,  Department of Computer Science
Royal Holloway,  University of London   TW20 0EX, England
Internet:  andy@dcs.rhbnc.ac.uk   phone: + 44 784 443696


----- End Included Message -----