Download An Overview Of The Damage Effects Electromagnetic Weapons

National Conference on Communication and Information Security (NCCIS 2012)
Daffodil International University, Dhaka, Bangladesh, 31 March 2012.
An Overview of the Damage Effects
Electromagnetic Weapons on Computer
Networks Architecture
Abidur Rahaman, Amran H. Bhuyian, Z. H. Mozumder
Department of Applied Physics, Electronics and Communication Engineering
University of Dhaka, Dhaka, Bangladesh.
E-mail: [email protected], [email protected], [email protected]
Abstract—Electromagnetic attack on computer
system is a growing concern now a days. Various
Electromagnetic weapons
with simple structure
supposed to be used by terrorist and weapons of
complex structure and with huge destructive power
are within the thinking of the different global power.
Both these type of Electromagnetic Weapons will
incur huge loss to the system as well as to the data if
are in use. This paper discusses the possible damage
effects produced by various types of electromagnetic
weapons and reviews a range of possible measures
in electrical and system design of computer
systems, which can be used to defend against
electromagnetic attack
Keywords- Electromagnetic Weapon, Computer
Systems, Hardening Strategies.
I.
INTRODUCTION
Computer systems are engaged in many
installations of state and corporate to give efficient
service to the people and to store data for decision
making as well as for future use. Many of these
installations are very sensitive and so the computer
systems that support those installations .The
sensitivity may be commercial or industrial as in a
bank or factory whose whole operation is
critically dependent on the correct and
continuous operation of its computer systems,
and it may be military or government sensitivity
where economic or even physical security is at risk.
Here we consider the threats that may be
present even without physical access to the
computer system components, the invisible but
insidious threats which may be propagated
through electromagnetic waves. Surprisingly the
technology required to attack a computer system
electromagnetically is very cheap; far cheaper than
that required to physically blow things up. It is
based on well-known physical principles, hence
will inevitably become available to the next
generation of ‘hardware hackers’. As computer
system architects, we must be aware of the threats
and methods of dealing with them.
II.
ELECTROMAGNETIC WEAPONS AND
DAMAGE EFFECTS
Any device which can cause semiconductor
devices within equipment to be exposed to unsafe
electrical voltages or power levels could be used as
an electromagnetic weapon. Electromagnetic
weapons fall into two broad categories in terms
of scale of attack and delivered power. The
first category covers Special Forces and terrorist
weapons which have low emitted power and
coverage and the second category belongs to
strategic and tactical military systems which are
built to destroy a whole site. The affects of an
electromagnetic weapon may be described in terms
of “Soft Kill” and “Hard Kill”. A soft kill is
achieved when the effects of the weapon cause
the target to crash or reset, lose data or get
into an unrecoverable state requiring a reboot. A
hard kill is achieved when sufficient energy is
delivered into the target system, such that it is
permanently electrically or physically damaged and
thus can no longer perform its function.
A. Terrorist and Special Forces Weapons
These are weapons are used from very short
distances and dedicated to destroy a single
machine, workgroup of machines, or disable the
networked systems in a single building.
1) HERF Guns: The term High Energy Radio
Frequency (HERF) gun can be used to qualify any
device which can emit and focus a high power
beam of RF energy. Most HERF guns operate at
frequencies above 100 MHz to provide required
directionality. Power levels need to be sufficient to
produce standing wave amplitudes of at least
hundreds of Volts on the wiring or
interconnecting cables associated with the victim
system. The primary damage effect of HERF guns
National Conference on Communication and Information Security (NCCIS 2012)
Daffodil International University, Dhaka, Bangladesh, 31 March 2012.
is the breakdown of MOS gates and BJT PNjunctions.
2) Portable Explosive Flux Compression
Generators: It is a strategic and tactical military
electromagnetic weapon[3]. A generator device is
designed to produce Mega Gauss magnetic flux at
very short distances. Cables and wiring exposed to
the generator field will have a single high voltage
pulse coupled into them. This pulse can punch
through transformers and destroy semiconductors.
Such device can be sited several meters from a
victim site, may be against the outside wall of a
computer centre machine room, and then
detonation may be done under timer control.
3) Tazers and Power Line Spiking: The Tazer
stun gun can be used to damage network interfaces
across large numbers of machines, by injecting KV
magnitude voltage pulses into network cabling.
Any device which can produce a very rapid short
circuit, and then open circuit, can be used to
“spike” mains power lines. Such sharp transients
travelling along power cables can penetrate
power supplies to damage components, as well
as damage data communication
interfaces
differential earth potentials. Both The attacker
using the Tazer and power line spiking will require
physical access.
B. Strategic and Tactical Military Weapons
Strategic and tactical military electromagnetic
weapons are at its immature but growing stage.
Such devices will be specifically designed to
destroy a wide range of electronic equipment
over footprints of up to hundreds of meters of
diameter.
1) Low Frequency (EMP) E-Bombs & HPM EBombs
An air bomb containing a pure flux generator
warhead is termed an LF EMP-bomb which is
capable of producing an intense magnetic field in
the near vicinity of the bomb when delivered. The
intense magnetic field will inductively couple into
wiring, producing a single high voltage pulse,
possibly with a ringing transient decay.
An air bomb containing a flux generator
powered HPM warhead is termed as HPM E-bomb.
Its primary effect upon delivery is to produce
microwave field strengths of between(1-100)
KVs per meter for
a duration of several
microseconds, in a footprint of hundreds of meters
of diameter. The microwave will produce high
voltage standing waves on wiring and cables, and
will also directly penetrate through holes in
shielding. There is also a possibility of High Power
Microwave Directed Energy Weapons (HPM
DEW) capable of delivering peak powers of
GigaWatts and average powers of hundreds of
Kilowatts. It can produce damage through high
voltage as well as thermal effects.
III.
COUPLING MODES AND DAMAGE EFFECTS
Two principal coupling modes are- Front Door
coupling occurs through antennas and destroys the
RF semiconductor devices in receivers and
transmitters. Back door coupling occurs through
power and data cables and wiring, and can harm
both power supplies, data receiver and transmitter
devices, and any other devices exposed upon
propagated deep into the equipment.
Undoubtedly the primary target of any
electromagnetic weapon is semiconductor devices.
Bipolar devices are primarily damaged by causing
breakdowns in reverse biased PN junctions they
may face further thermal damage due the direct
effects of the weapon, or thermal runaway as a
natural fate of device after breakdown. Field Effect
Transistors like MESFET or MOSFET are
damaged by very high electric fields that punch the
Gate dielectric caused by the weapon. Damage can
amount to gate leakage, degrading performance, or
permanent breakdown causing permanent transistor
damage. In all those cases the equipment power
supply will contribute extra damage.
National Conference on Communication and Information Security (NCCIS 2012)
Daffodil International University, Dhaka, Bangladesh, 31 March 2012.
Figure1: System Level Susceptibilities.
IV.
HARDENING STRATEGIES
Hardening is the technique of protecting
computer systems from electromagnetic attack.
Computer or communications equipment is a nonredundant system. Therefore a partial hardening is
not a proper measure. Equipment and sites must be
comprehensively hardened. Because the threat may
be operating within a frequency band spanning tens
of kilohertz to tens of gigahertz, implementation
can incur much expense. There are many options
for host level hardening like dissipation of effects
which is accomplished by using either passive
networks, gas discharge devices or fast switching
protection diodes, that will dissipate the coupled
wave or pulse to a level that it will not be able
damage exposed semiconductor devices. A more
robust strategy for protection is exclusion of
electrical effects. This is achieved by using
comprehensive shielding of sensitive components,
by creating Faraday cages around sensitive
components, and also by using non-electrical
channels for the transfer of data and power. This
ensures that no path exists via which damaging
voltages or radiation can get into the equipment.
These copper connections used for connecting
different peripherals to computer system constitute
potential vulnerabilities. Replacement of these with
optical fibers or free space optical transceivers may
solve problem. For keyboards and mouse, these
could also be built as wholly optical devices. The
comprehensive use of optical fiber for LANs as
connecting cable as replacement of copper cable
removes vulnerability of the networking
infrastructure.
For Site level hardening the whole building or
rooms in buildings can be turned into Faraday
cage. Inside such sites, unhardened equipment may
be safely used. But cost is a major factor here.
There is also a problem with how to transfer
power efficiently into a Faraday cage without an
electromagnetic path between the interior and
the exterior of the cage. A solution could be the
use of a closed cycle fuel cell scheme.
Figure 2: Comprehensive Host Hardening Strategies.
V.
CONCLUSION
Electromagnetic weapons structure may be simple
with possibility of recovery or may be complex
with huge destructive power with potential to
permanently damage a computer system .It will
incur huge economic loss if computer system of
financial sector is attacked by such weapons.
National Conference on Communication and Information Security (NCCIS 2012)
Daffodil International University, Dhaka, Bangladesh, 31 March 2012.
Furthermore such attack may cripple the whole
government in the age of E- governance. Public
Utility system which are becoming computer
controlled and networked system may get down
upon such an attack and may trouble a whole city
or the whole nation. So system designers should
have active concern on preventing their system of
Electromagnetic weapons attack and take
hardening measures. Further research can be done
on improvement of hardening measures.
www.heritage.org/Research/HomelandSecurity/bg2199.cf
m.
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Kopp C., A Doctrine for the Use of Electromagnetic Pulse
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Micron DRAM Data Book, Micron Technology Inc,
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Protecting Your Personal Security in the Electronic Age"
1996 Thunder's Mouth Press, 632 Broadway 7th Fl, New
York,
New
York,
ISBN:
1-56025-132-8,
(http://www.infowar.com).
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