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Hacker Tinkering With Yahoo Stories
Lifter writes "A hacker named Adrian Lamo had access for three weeks to the web-based content control system for Yahoo!'s news section, according to a story at SecurityFocus. He tinkered with a couple of stories without anyone noticing, then edited an August Reuters story about Dmitry Sklyarov, so that it said that Dmitry's program raised "the haunting specter of inner-city minorities with unrestricted access to literature, and through literature, hope." He also added a quote by John Ashcroft,"They shall not overcome. Whoever told them that the truth shall set them free was obviously and grossly unfamiliar with federal law." Funny stuff in itself, but the SecurityFocus story explores the harm that could come from a trusted news site being easily hacked in these times."
"Signing" content with MD5 would be pointless. If I were going to modify the content, I'd update the MD5 sum, too. You can't do that with PGP unless you've got the private key.
I like to play children's songs in minor keys.
"We're all sons of bitches now." --J. Robert Oppenheimer
No, the Comet jetliners did NOT explode due to explosive decompression. That doesn't even make sense; it is sort of like saying a match burns because it combusts.
What happened with the Comet was a result of crack propagation and stress concentration.
Stress concentration (for those who don't already know) is a phenomenon that occurs when you have a discontinuity in a load bearing structure. Imagine a plate with a hole in it which is under load. The area of the plate away from the hole has a fairly constant stress that can be calculated with your "ideal" equations. As you get near the hole, however, the stress in the material increases; it is as if the hole literally concentrates the stress into that area, hence the name "stress concentration." The smaller the radius of the hole, the greater the stress concentration. In order to keep the stress in the material low, engineers will design things so that they have as large a radius as possible anywhere the geometry changes. Square corners are avoided, because at a perfectly sharp corner you have an infinitely small radius and therefore an infinite stress concentration. Take a look at the rounded corners and stress reliefs on some items around your home or office. The material around a sharp corner will fail under almost any load. At the point of cracks or tears you also have one of these "near infinite" stress concentrations. That is how the little sharp cut at the "tear here" location of potato chip bags and ketchup packets works.
Well, the engineers who made the Comet put in square windows, with those wonderful stress concentrators in the corners. As the aircraft was pressurized and depressurized it stressed the material and in the area around the corners of the window the stress was highly concentrated and the material failed... it cracked. And the crack is also as stress concentrator, so the crack grew with every cycle of pressurization and depressurization until the structural integrity of the airplane was compromised and the force caused by the pressure difference between the inside and outside of the aircraft "unzipped" it like someone opening a bag of chips. Cracks in aircraft structures still cause problems, but it doesn't cause the airplane to "explode" like something out of the movies. One or two sections of the skin may be peeled off, and the airplane decompresses "suddenly" (which is why it is called explosive) but the airplane doesn't just detonate. Some of you may remember back in the 1980s this happened at the intersection of a structural support and skin to a 737 headed to Hawaii and it lost 18 ft. of skin (and a flight attendant).
Could a bullet hole cause similar rapid crack propagation and sudden decompression? Not a clean one, the radius is too big. I suppose little star cracks could exist around the hole that could propagate, in theory; but I doubt the damage would ever be worse than that experienced by the aforementioned 737. I am familiar with aircraft conceptual design, but am not an expert on aircraft survivability so IANAEOAS, however I have never heard of any survivability enhancement programs that focus on preventing structural failure from projectile or fragmentation damage to the skin of pressurized aircraft. Structural failure is one of the rarest causes of military aircraft loss(fuel and propulsion systems are the big problems), and is not usually a high priority on increasing aircraft damage tolerance. Civilian aircraft structures are not sufficiently different to negate the usefulness of this historical data. Of the 34 modern airliners that were subjected to in-flight bombings, 56% survived; of those only 10 crashed because of structural failure. If anyone is interested in the effects of aircraft pressurization on enhancing damage can take a look at http://www.dtic.mil/ndia/aircraft/21.pdf. It is significant, but not what I suspect most people would imagine. My best guess, is that any shot which punctures the skin will cause pressure loss. It would take a lucky shot in an older aircraft to unzip a portion of the skin, even then aircraft would likely not be lost. A modern airliner with multiple load paths would be even harder to "unzip," maybe impossible without multiple penetrations. As I said, though IANAEOAS, so if anyone does have specialized knowledge to the contrary I'd certainly like to see it. If no one does have any data or specilized knowledge in this area that contradicts this, then lets please stop rehashing this "bullets vs. aircraft" debate. Of course the smart thing would just be to use frangible bullets that won't penetrate.