I am just a programmer; however, for three and a half years I worked at CTR Division here at Los Alamos. I augmented ( in a very minor way, ) and maintained the control system for a series of Magnetic Fusion Energy experiments. The programs ran in "real time" and attempted to use magnets to "contain" and shape a plasma. The plasma is very like the ball of gas in your neon light over your desk, but instead of neon, we used a vacuum and a tiny amount of sulfur-hex... ( that same stuff that was in the tank in Oklahoma that the workmen dropped because it was overfull ). The plasma is started by discharging a huge arc across a quartz bottle that contains the vacuum and the sulphur-hex. The computer controls the point at which huge capacitors discharge through the quartz bottle. There are many independent power supplies that discharge through different portions of the quartz bottle. The computer program controls "precisely" when each power supply or capacitor bank discharges into the quartz tube. These power supplies/ capacitor banks are placed by the physicists such that the ball of lightning ( plasma ) formed inside the quartz tube is kept from touching the inside of the tube. The power supplies form a magnetic bottle inside the quartz tube ( the quartz tube is about 14 inches across, ) and under computer control have kept the plasma alive and away from the edge of the 14 inch wide tube for more that 3/100 ths of a second. Now the tube has been made about twenty feet long and the ball of plasma has been created, stabilized, and then slowly ( different time frame ) moved to the other end of the tube; controlled by a Pr1me 300 ( I'd guess that is about the same as any of the 68000-based micros ). The Pr1me did all of this stuff remotely over a fiber-optic CAMAC highway. The point of this was that any failure of the control system was capable of killing personnel. The "man in the loop" who was running the control system was not necessarily knowledgeable about what he was controlling ( sometimes this was me... ). The software was much smarter than the operator and certainly swifter. There is no way that I could hit the "kill" switch before the plasma got loose. The "kill" switch was used as a mechanical lockout ( in conjunction with the software lockout and the "key switch" we had installed ) while we were testing the control system. I sit here and am bored by endless arguments on Unix "news" that the Strategic Defense Initiative contains portions which "can't be programmed" because they have this or that seemingly insurmountable characteristic. I look at my friends MacIntosh and think fondly of the days when I helped with the payroll and accounting for a 2000 person company on an IBM 1411 which wasn't the machine that the Mac is... What may be "impossible" for me is resting forgotten in one of the software libraries down the hall.
To: "risks@sri-csl"@Sushi Reply-to: email@example.com Has anyone noticed the proposals made in the article "Security Without Identification: Transaction Systems to Make Big Brother Obsolete" by David Chaum in the October issue of Communications of the ACM (vol 28, # 10, 10330-1044)? If so, what is the response? Basically, he asserts that it would be in the interests of both individuals and organizations to adopt a system whereby transactions would be essentially unforgeable and untraceable. Jim
To: mcgrath%mit-oz@MIT-MC.ARPA What you suggest might indeed be an improvement. However, remember that nothing is guaranteed unforgeable. You will always have some points of vulnerability, and you have risks of spoofing, clever system programmers, embedded Trojan horses in hardware and software, etc. If you were to rely blindly on such a system, you would be making yourself even more vulnerable! You can indeed come closer to having an unforgeable communication, but believing that you have it may actually increase the risk. Peter
To: mooremj@EGLIN-VAX.ARPA cc: LIN@MC.LCS.MIT.EDU, risks@SRI-CSL.ARPA > As has been pointed out by previous contributors, human intervention during > boost phase is out of the question, since it's all over in a minute or two. From: mooremj@eglin-vax For SLBMs, or missiles aimed at Europe from the western Soviet Union, I'll grant the point. But for land-launched missiles aimed at the US, I estimate at least a five-minute boost. If this is wrong, someone please correct me! Currently, the SS-18 has boost phase of about 5 minutes = 300 sec. MX has a boost phase of 180 sec. Probably 120 sec boost isn't impossible if you really tried to do it (as the Sovs will undoubtedly do if we ever deploy SDI). Indeed, the US is studying fast burn boosters even as I write this.
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