_________SWAT MAGAZINE ISSUE TWENTY SEVEN MARCH  2000 __________
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 /                        French Eavesdroppers                      \
/                              By Frak                               \
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The French government covertly eavesdropped on wireless calls made to 
and from UK mobile phones, according to a report in the Jan. 23 issue
of the UK's Sunday Times.

French intelligence services routinely monitor British cellphone calls
from at least eight centers scattered across France, which are "aiming"
their receivers at "British defense firms, petroleum companies and
other commercial targets," the paper reported.

The Sunday newspaper hints that the British government and relevant
defense company senior managers are well aware of the problem, and are
being told not to discuss sensitive matters on their mobiles as a
result.

The GSM cellular standard - as used in the UK - has a maximum range
between the mobile and a base station of around 35 kilometers, to
allow up to eight wireless calls to occupy a single GSM channel.

However, GSM transmissions can reach up to 150 kilometers or more, a
facility that is exploited using GSM cellular base stations located in
coastal regions.

Such base stations "slip" the timing slot available to mobiles by up
to 100 percent, allowing mobiles up to 120 kilometers away to place
and receive GSM calls.

The disadvantage with this, Newsbytes notes, is that the base station
call handling capacity is cut in half.

As reported previously, there have been several reports that the GSM
encryption system - actually quite weak - can now be broken by "brute
force" decryption techniques.

Reports of around 18 months ago suggested that the technology needed
to decode a GSM transmission cost around $32,000, a figure that is
certain to have fallen in recent times, and well within intelligence
service budgets.

The Sunday Times quotes "an executive within one British defense firm"
as saying that top people use the same mobile telephones as anyone
else, without any sort of high-tech security equipment.

"There is an understanding that we need to be careful. People never
say anything they would not want heard elsewhere - especially at
sensitive times and during projects when other people may have an
interest in listening," he told the paper.

The key to eavesdropping on the GSM calls, the paper said, is that
the listening station needs to know the number of the mobile phone in
question. After that, the paper said, it is a relatively easy task to
listen to all calls made and received.