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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. [3] Kopp C., A Doctrine for the Use of Electromagnetic Pulse Bombs, Working Paper No.15, Air Power Studies Centre, Royal Australian Air Force, Canberra, July 1993. [4] Micron DRAM Data Book, Micron Technology Inc, Idaho, 1992.MOTO3 - Motorola RF Device Data, Motorola Semiconductor Products Inc, Arizona, 1983. [5] Winn Schwartau, "Information Warfare - Cyberterroism: 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). REFERENCES [6] [1] Carlo Kop and Ronald Pose , The Impact of Electromagnetic Radiation Considerations on Computer System Architecture. Dept of Computer Science, Monash University, Clayton, Victoria, 3168, AUSTRALIA. Hughes to Build HPM SEAD Demonstrator, pp.29, Journal of Electronic Defence, February, 1996 (Last Accessed 5-10-2012 ). [7] Ramo S. et al, Fields and Waves in Communications Electronics, New York, John Wiley & Sons, 1965. [8] The EMP - A Triangular Impulse, 2.29, A Handbook Series on Electromagnetic Interference and Compatibility, Don White Consultants, Maryland, 1978. [2] Jena Baker Mcneill and Richard Weitz, Electromagnetic Pulse (EMP) Attack: A Preventable Homeland Security Catastrophe, The Heritage Foundation. October 2008,