Much discussion this morning about EMP, electromagnetic pulse weapons, HERF guns, Winn Schwartau's "Information Warfare" scenarios, TEMPEST, etc. Not closely related to Cypherpunks themes, but lots of speculation is continuing. I happen to know a fair amount about chip vulnerability to various kinds of radiation and electrostatic discharge, and have had contacts with folks who know Schwartau. (I was also interviewed for a Schwartau-oriented BBC television program called "The I-Bomb.") Here's what I know: * EMP can of course zap devices. High electric field gradients can induce voltage drops that blow inputs, burn out circuits, etc. Lots of mechanisms for this, of course. Latch-up in CMOS circuits, field oxide overvoltage breakdown, etc. There is an entire sub-industry devoted to electrostatic discharge (ESD), with conferences, products, consulting services, etc. * However, getting the voltages coupled into circuits is another matter. Modern chips can usually handle static charge buildups that are in the tens of thousands of volts range (input protection devices are on the input pads). Static discharge should be avoided (wrist straps, etc.), but most modern devices will survive the static discharges that folks can generate. * The point? A _distant_ (tens of meters away) source of electromagnetic fields will have a pretty hard time of creating field gradients able to equal these 10,000 volt local fields caused routinely by static buildup. (Electric fields are of course measured in terms of "volts per meter"...do the math.) * The traditional EMP work is well-covered in each year's "Nuclear and Space Radiation Effects Conference," the Proceedings of which are included in the December issue each year of "IEEE Transactions on Nuclear Science and Space Radiation Effects." I advise anyone interested in this topic to consult these sources. (I've been to a few of these conferences, beginning in 1978.) * Most of the traditional EMP work is oriented toward the detonation of nukes in orbit, where the interaction of the photons from the bomb with electrons in the upper atmosphere create an electromagnetic field of millions of volts per meter, the so-called "electromagnetic pulse" that blows circuits. (This effect was apparently first noticed, by U.S. scientists at least, after a 1962 high altitude burst over Johnson Atoll in the Pacific, with electric circuits as far away as Hawaii being blown.) * Schwartau has not, to my knowledge, ever seen a direct demonstration of the effects he is describing in his book. In fact, much of his "HERF gun" stuff is admittedly speculative. * He has gotten interest from British intelligence (MI-5 or MI-6, not sure which) in his "scenarios" for knocking out financial centers with EMP bombs and HERF guns. A friend of mine, who can speak up if he wishes here, has had some contacts with Schwartau and may have started to do some preliminary experiments on this stuff. (The EMP/HERF folks in governments have of course a lot of experience here. I'm just saying that the "Schwartau crowd" appears to just be getting started on actual experiments, so any speculations in "Information Warfare" should be taken as just that, as speculations.) * As a matter of commenting on one thread about damage to the "HERF gun" itself, the conventional notion is that such a device would be a "set and forget" device, with a suitcase planted near a corporate office complex and set to "detonate" some time later. All the talk about reuse and damage to the operator is beside the point. (As is the speculation about effects on the human body....bodies can withstand incredibly high fields, so long as a ground path for current does not form (electrocution)....I could go on about this, but won't.) * In my opinion, Schwartau's chief interest is in spreading fear and concern about the "vulnerability" of the world's "information infrastructure." This cranks up interest in his book, in getting talk show interviews, etc. He may have "patriotic" motives as well, but I think a large part of what we're seeing is the usual, and increasingly common, journalistic hype. This is not to say there is no basis for concern, just that this is not the first and foremost concern. After, cutting power lines has long been an easy way to knock out economic activity--it may have recently happened in Penang, Malaysis, for example, where many chip assembly plans were knocked off-line for a few weeks by a power cable cut. This is all I'll say on the current debate on TEMPEST, HERF, EMP, etc. --Tim May .......................................................................... Timothy C. May | Crypto Anarchy: encryption, digital money, tcmay@sensemedia.net | anonymous networks, digital pseudonyms, zero 408-728-0152 | knowledge, reputations, information markets, Corralitos, CA | black markets, collapse of governments. Higher Power: 2^756839 | Public Key: PGP and MailSafe available. "National borders are just speed bumps on the information superhighway."