Counter Intelligence Measures:
RE:
Your PLDT phone
Phone taps, especially for people who use phones a lot, are a good way
to pick up information. As well as taping your voice conversations,
with the appropriate equipment, private investigators as well as the
'official' government departments can monitor fax and computer/modem
transmissions too. There is no way to prevent, or detect, any official
(Government) telephone tap. Today, with digital telephone switching
technology, government agencies do not even have to physically visit
your exchange to set a tap on your phone - they just instruct their
computer to redirect a copy of your phone conversations to their computer
systems. Unofficial taps are another matter. Generally unofficial taps
are physically connected to your phone line, either taking power from
the line (in which case, the line will be cut and the device connected
into the circuit) or picking up the phone signals by inductance (in
which case the device will have a coil of wire around the phone line
- with no physical connection - and it will have to have its own power
supply). Those with direct connection will reduce the voltage on the
telephone line, but voltages can vary so much anyway they are still
difficult to detect unless you have very expensive equipment. The traditional
image of official phone taps is a large tape machine which records when
you pick your phone up. These machines produced hours of tape, which
all had to be listened to costing lots of staff time and money. This
meant tapping was only used where the results were guaranteed, or it
was an absolute necessity to have continuous monitoring. Today, with
computer technology, this is no longer the case. The phone tap plays
into a computer. The computer is programmed with snippets of your voice
speaking 'keywords' - for example "hit", "nuclear", "explosive", "bomb",
etc. - gathered from previous phone recordings. When the conversation
has been recorded, the computer digitally examines the playback looking
for these words. If it finds a match then it keeps the recording for
later use. This has made tapping easier, and thus more widespread. There
is absolutely no way to defend yourself against phone tapping - you
just have to work around the problem. Rather than organising things
on the phone you have to do it in person, or invent a variable and confusing
set of codewords to fool the listeners. If you have a computer things
get easier - it is possible to send encrypted (scrambled) messages via
a modem, or just on a floppy disk through the post. Even so, the growing
power of computers means that unless you have a very good encryption
program the code may be broken eventually. Mobile phones are another
option - but make sure it is the 'digital' type which encrypts the call.
Even then, this does not stop the Government eavesdropping on you because,
via the phone company, they will have access to your code. Another practice
used by various tappers, and widely used by the police and security
services, is number logging. The authorities only have to have a warrant
to actually 'listen' to the call - they can make a note of the numbers
dialled from the premises without any control whatsoever. Also, now
that exchanges are fully digital, they can also find out the number
of people calling you. From this information it is possible to draw
up a 'web' of your contacts and associates.