Tuesday 15 January 2013

Radiation Comprehension

If you like to watch television while you use your computer, you may have noticed something funny happening when the channel is turned to certain stations. With the computer on, channel two on my television is complete static, while channels 3 and 4 get decreasingly snowy. This happens when electromagnetic fields radiating
from my computer and cables are picked up by the televi-sion antenna. If I'm watching channel 2, 1 can even make out a very fuzzy representation of what I see on the computer screen.

There is a simple reason for this happening. The various components of a computer - amplifiers, cables, the coupling between cables, the power supply to power line coupling, switching transis-tors, the ground loop, internal wires, and even printed circuit boards - all act as antennae to con-duct electromagnetic radiation. The
components, cables and whatnot will not only pick up the radia-tion, but transmit it as well, sometimes re-emitting it at some distance from the source equipment. Nearby electrical wiring and metal pipes can further act as antennae. Computers operate at radio frequencies and so they are also radio transmitters.
That's why the Federal Communications Commission must ap-prove all computers (and many other electronic appliances) before they can be sold in the United States. The FCC wants to make sure those radio emissions aren't strong enough to interfere with other licensed radio receivers (such as television sets). In fact, there
have been cases of unregistered computer monitors whose screens have been picked up on the next-door-neighbor's television set. This sort of thing is more likely to occur when the neighbor has a black and white television and the computer has a composite monitor, because a black and white set can more easily adapt the syn-chronization signals that it picks up from a com-posite monitor (especially if the TV has an antenna amplifier attached).

When my television receives computer fre-quencies, it is doing so accidentally. Imagine the consequences of someone setting out to purposely receive radiated information. Indeed, such a thing is possible, and has been going on for quite some time. For years the Department of Defense has stashed away its most hush-hush
computers and communications devices in copper-lined rooms to prevent radiation leakage. They have also pro-duced guidelines for a security standard called TEMPEST ( Transient Electromagnetic Pulse Emanation Standard. ) which defines how military computers are to be constructed so that the radiation leaking from
them is minimal.

Special military computers might be well pro-tected, but your run-of-the-mill PC or terminal is not. The FCC ensures that equipment won't inter-fere with other equipment; it makes no promises that equipment is safe from prying eyes. In fact, those eyes don't even have to be at the scene of the crime. There is an electronic
marvel called the Van Eck device which picks up your favorite leaked radiation and projects it onto a television screen. Hook up a VCR to the television and you've got a living document of everything that goes on in your target's computer account.

Radiation Comprehension

If you like to watch television while you use your computer, you may have noticed something funny happening when the channel is turned to certain stations. With the computer on, channel two on my television is complete static, while channels 3 and 4 get decreasingly snowy. This happens when electromagnetic fields radiating
from my computer and cables are picked up by the televi-sion antenna. If I'm watching channel 2, 1 can even make out a very fuzzy representation of what I see on the computer screen.

There is a simple reason for this happening. The various components of a computer - amplifiers, cables, the coupling between cables, the power supply to power line coupling, switching transis-tors, the ground loop, internal wires, and even printed circuit boards - all act as antennae to con-duct electromagnetic radiation. The
components, cables and whatnot will not only pick up the radia-tion, but transmit it as well, sometimes re-emitting it at some distance from the source equipment. Nearby electrical wiring and metal pipes can further act as antennae. Computers operate at radio frequencies and so they are also radio transmitters.
That's why the Federal Communications Commission must ap-prove all computers (and many other electronic appliances) before they can be sold in the United States. The FCC wants to make sure those radio emissions aren't strong enough to interfere with other licensed radio receivers (such as television sets). In fact, there
have been cases of unregistered computer monitors whose screens have been picked up on the next-door-neighbor's television set. This sort of thing is more likely to occur when the neighbor has a black and white television and the computer has a composite monitor, because a black and white set can more easily adapt the syn-chronization signals that it picks up from a com-posite monitor (especially if the TV has an antenna amplifier attached).

When my television receives computer fre-quencies, it is doing so accidentally. Imagine the consequences of someone setting out to purposely receive radiated information. Indeed, such a thing is possible, and has been going on for quite some time. For years the Department of Defense has stashed away its most hush-hush
computers and communications devices in copper-lined rooms to prevent radiation leakage. They have also pro-duced guidelines for a security standard called TEMPEST ( Transient Electromagnetic Pulse Emanation Standard. ) which defines how military computers are to be constructed so that the radiation leaking from
them is minimal.

Special military computers might be well pro-tected, but your run-of-the-mill PC or terminal is not. The FCC ensures that equipment won't inter-fere with other equipment; it makes no promises that equipment is safe from prying eyes. In fact, those eyes don't even have to be at the scene of the crime. There is an electronic
marvel called the Van Eck device which picks up your favorite leaked radiation and projects it onto a television screen. Hook up a VCR to the television and you've got a living document of everything that goes on in your target's computer account.

Always A Way

Think about the enormous amount of power government possesses over us. Think of the billions of dollars it can spend to pry into our lives, to pho-tograph us, record our movements and our daily activities. Think of all the expertise available to such a powerful entity. Anything that government - or big business, or anyone in power for that matter -wants to know about, wants to happen, or wants to change, will become known to it, will happen, or will be changed.

When we start to think about all the covert ac-tions going on around us, and all the myriad ways in which we don't even know we are being ma-nipulated or spied upon, we begin to think of gov-ernment agencies as unbreakable, unstoppable... unhackable. And even if we think we have a chance at hacking it, we know we will end up in prison.

But all of that is simply untrue!

Government agencies are limited in what they can do and in what they know. You only have to look as far back as Operation Sun Devil a few years ago, when Steve Jackson got his games taken away because they were thought to be a menace to socl-ety. Sure, the Secret Service and the FBI may be powerful, but maybe they arefeeble-minded too.

We read about all these scary spy gadgets that have been developed that can read our lives like a README.DOC. We hear about the "impenetrable" government computer systems that have been set UP, and we are scared away because they sound so hermetically protected. For example, we know that any transmission of an interesting nature has a 100% chance of being intercepted. Therefore, all those spy guys in Washington have set up ul-tra-secure network links in an effort to protect their valuable secrets. Their most safeguarded lines are fiber-optic cables buried deep below the surface of the earth and sealed in gas-filled pipes. These are strictly isolated systems - no connections to outside phones or computers, so no hackers can gain access by dialing in. Even if a hacker were to dis-cover where the (unmarked) underground lines are, and even if that hacker were to manage to dig down undetected, and cut open the pipe to tap the cable, the drop in gas pressure instantly sounds an alarm.

This is heavy protection, and sounds like it would be impossible to hack, especially when you realize that even if there were some way to get at those lines, you still need various levels of permis-sions, passwords and access codes to reach the highest and most secret classifications of data.

But think again. Never forget that behind every complicated system, is nothing more than some human beings. And what are human beings if not fallible? In the case of this seemingly impenetrable system, we can imagine the humans who sit night after peaceful night, watching their TV monitors, waiting for the alarm to sound that signals a breach. They're probably asleep more often than awake, especially if the temperature and humidity is high in their work area. If ever the alarm did sound, they probably would ignore it, or wouldn't know what to do. Or they would take a quick look out the window and go back to sleep.

Even if the guards did go out and check the wires to make sure everything was okay, do you think they would continue checking them after five or six false alarms? "The boy who cried wolf' trick always works, especially on a dark and stormy night. No guard is going to go out sloshing through the mud and rain to investigate an intruder he knows won't be there. There is always a way. Don't be fooled by first appearances.

And here are some more ways you can beat the security:

General Purpose Microcomputers

Now we come to the third We of Public Access Computer from that list I gave several pages back: the General Purpose Micro. I'm going to be talking here about IBMs and MS-DOS machines, although nowadays we're seeing more and more Macs out in the open for public use. Of course, all techniques I discuss can be translated to any computing envirorunent.

Let's say you call up your local library and make an appointment to use a computer there, for word processing or business or whatever. Ordinar-ily these are nonnetwork machines, although if there's more than one they may be connected to the same printer, or to some other peripheral. At col-leges, the word  processing software may be on a non-writable disk - on some sort of mainframe or minicomputer. There are also businesses set up now where people can go to rent time on a com-puter to type up their r6sum6s or reports, and have them printed out on a good quality printer. Set-ups such these can be exploited to the hacker's benefit.