The oscilloscope is the most valuable piece of equipment to the hacker.
With this device the secrets of all but the most secure systems are laid
bare. A dual trace model is essential as normally two signals have to be
examined and compared. Television synch triggering is an advantage. A
ten megahertz bandwidth is the ideal lower limit. A few professional
hackers use digital storage oscilloscopes. While these scopes are useful,
the majority of professional hackers try to use the least amount of
equipment as possible. This may seem strange in some respects. The
system designers developed the system with high cost test equipment.
They try to make their system as secure as possible against the best
equipped hacker. They fall into the trap of thinking that they have
developed the ultimate system. By using the minimum of equipment, the
hacker forces himself to innovate. The use of the scope will be covered
later.
The next item of equipment is a video test signal generator. This device
can be cost anything form thirty pounds to three thousand pounds.
A lot of hackers rely on microcomputers to provide the test signals. There
is a disadvantage in this use of a computer. Computers generate a lot of
R.F noise and as a result the case of the computer has to be coated in
some sort of R.F shield. A suitable aerosol is available from a number of
suppliers.
Professional hackers generally use computers to provide their test signals.
This may seem strange as you would expect them to use the best possible
equipment. The computer is more versatile than an ordinary video
generator. It is almost impossible to find two identical test cards. Most of
them carry station identifiers. This fact is not of any great significance
with analogue signals but with digital encryption it can be essential. Most
digital scrambling systems are hacked during the test card period. Services
rarely scramble from the start and so the hacker has access to the test
card. The computer generates this test card and compares it to a
'snapshot" of the encrypted signal. With complex systems, the
comparison process can take up to six weeks or longer.
The next piece of equipment is the low pass filter. This is a very useful
item when the signal being examined is noisy. A cut-off frequency of one
megahertz is commonest. This unit is used to remove most of the video
information from the signal so that the synch signals can be observed.
A digital storage oscilloscope is an expensive item that a lot of hackers
cannot afford. There is a way around this problem - build a digital storage
circuit. There are basically four circuits involved an analogue to digital
converter a RAM storage circuit, a digital to analogue converter and some
triggering circuitry. A number of designs have been published in various
electronic journals so the constructional details will not be given here.
The most valuable use of the oscilloscope is in comparative analysis of
two signals. A dual trace scope is virtually essential as it is very difficult
to do any serious work with a single trace unit. Some hackers use an
oscilloscope multiplexer. One such unit is available from Thandar Ltd.
The main disadvantage of such units, after their cost, is their bandwidth.
The majority of those on the market have an upper limit of five hundred
kilohertz. This is all right for looking at synch signals but is useless for
video or high speed digital signals. When designing and building a
multiplexer the main thing to ensure is that the sampling frequency is at
least three times the maximum signal frequency. In order to make the
device as future proof as possible an upper signal frequency limit of
twelve megahertz Is recommended.
There are some hacker programs available for microcomputers. They are
aimed at the professional hacker rather than the amateur. The program
user draws the scrambled video waveform on the screen using a graphics
tablet. The program then analyses the waveform and first draws the
block diagram for the descrambler and also produces a circuit for the
descrambler. The waveform and the circuit are then stored so that a
library of scrambling systems is built up. Don't bother trying to find such
a program in any magazine or journal as they are only available through
the elite hacker networks.
Database programs are available for virtually every computer. Such a
program can be a powerful ally when it comes to storing your information
on various scrambling systems. The main headings for the information
would be system type , audio type , suppressed synch , frame inversion ,
line inversion, digital video and digital) audio. A new scrambling system
could then be checked against a list of known systems and a list of known
descrambler circuit blocks could be suggested for dealing with the system.
The template for such a database is given below. This particular format
is known to be in use by a number of the top European hacker networks.
The same type of database is used throughout these networks in order to
ensure the rapid exchange of data on any new system.
This template is also used by the Scramble Fax newsletter and as such is
a standard format. It is most commonly implemented in Database where
the user is allowed to have large text memo sections in some key points.
System File Reference:
System Name:
Start Date:
Audio Type:
Video Inverted:
Video line Inversion:
Video Frame Inversion:
Random Line Inversion:
Alternate Line Inversion:
Alternate Frame Inversion:
Horizontal Synch Suppression:
Frame Synch Suppression:
Horizontal Synch Replacement:
Frame Synch Replecement:
Pulse Suppression:
Sine Suppression:
Line Delay:
Audio On FM Carrier:
Audio On Sideband:
Audio Spectrum Inversion:
MAC System: Digitised Audio:
DESed Digital Audio:
Origin Of System:
Media Cross References:
Pro Media References:
Other Users Of System:
Descrembler Circuit Known:
Possible Useful Circuits:
Availability Of Official Descramblers:
Custom ICs Used:
Function Of Custom ICs:
Descrembler Addressing:
