They do the force calculations, but don't think this through far enough.
Assuming a spherical iron asteroid with a 100m radius (the article mentions two football fields across) and a 20 ton ship you can provide a maximum gravitational force of about 1 pound. This is find and dandy and could provide a deflection of nearly the diameter of the earth over a decade period.
But...
The problem is how to produce that required force on your ship without impacting the asteroid. Conventional rockets or ion thrusters would necessarily be directed in the direction of the asteroid which would nullify any net force on the system (ship+asteroid). If you get enough distance between the asteroid and the ship so yout thrust can miss the asteroid and provide a net force, the force you can provide on the asteroid due to gravity drops as the square of the distance and becomes unusably low. You'd need litterally centuries or millenia of advance warning!
If anyone has ideas how to avoid this problem, I'm all ears.:)
Any boolean value that is not false must, by definition, be true.
True enough, but logic statements can be true, false, or neither (ill-defined?). Particularly self-referential statements often fit the 'neither' category. It's the assumption that logic statements must be either true or false that lead to paradoxes.:)
Illegal means that a law has been broken, and implies a violation of criminal law.
Sorry to be pedantic, but the word 'illegal' does NOT imply a criminal violation. Illegal simply means that something is prohibited by law. It makes no distinction of criminal/civil law.
I agree with the rest of your statements though.:)
The solution is not unique unless there are additional restrictions. For example:
SEND == 9552, MORE == 1005, MONEY == 10557
SEND == 9554, MORE == 1005, MONEY == 10559
SEND == 9553, MORE == 1005, MONEY == 10558
...all seem to work fine.
Do the letters each have to represent a UNIQUE decimal digit?... or be non-zero? It also seems like a requirement to be unique can't be satisfied either, so what's missing here?
Can I ask, unrelatedly, about your feelings toward the term "identity theft"?
Yes. The term "identity theft" is also a ridiculous one. If someone uses my SSN to pretend to be me, they haven't "stolen" my identity. I'm still the exact same person I was before hand. The actual term I believe is "Criminal Impersonation".
Sorry... my brain must have been off this morning.;) I'll have to claim sleep deprivation and a cranky attitude from 5 days of a bad flu....and obviously a bit of cluelessness.
I think you're missing the point of all the other posters here: That the attacks would almost certainly be IMCOMPATIBLE. For example: Suppose an attack is found for SHA1 that is just like this one in nature. You seem to think that these two attacks can be used in conjunction with each other, but that just isn't the case. The modifications to extend the file while preserving SHA1 almost certainly WON'T preserve the MD5 stamp match previously created by the other attack. The same would be true in the reverse order. Bottome line: Even with attacks like this against both algorithms, if you're trying to use this on a file that gives both MD5 and SHA1, then you can't combine the attacks and create new files that match BOTH MD5 and SHA1 of the original. If you still don't understand this, please, please don't try to make a living in cryptography.
So you use your MD5 attack to generate a large set (2^60 or however many you need) of RPMs matching the MD5, then you use your SHA1 attack to find one among them which matches the SHA1 too, or vice versa.
Generate 2^60 RPMs?
Then TRY to find one that matches the SHA1?
You're kidding, right?
Obviously you and I have far different ideas of what "computationally feasable" means.
you can make the file seem legit by generating a "bad" file with the same checksum.s
No you can't. Not with the same MD5 as someone else's exe. Please RTFA before posting. The attack does NOT allow you to produce a file that matches another arbitrary file's MD5.
The "atomic age" was just a pipe dream, people will soon realize that the "space age" isn't any different.
The atomic age was just what it seemed. It saw the development of technologies from the Atomic Ramjet and Nuclear Rocket engines to Thermo-electric Generators that could run for decades. Fuel pellets the size of a marble that hold the energy equivalent of tens of thousands of gallons of hydrocarbon fuel. The technology to free ourselves from our dependence on foreign oil and the effects that dependence is wreaking on our economy.
That technology is all still here, but naive people like you have been deluded into believing that it was just a pipe dream.;)
however, the sky is not the limit as far as fuel density goes
No, real the energy density limit is E=mc^2.
If idiots and bought-and-paid-for "scientists" hadn't worked so hard to kill off the atomic age we'd probably be all over the solar system by now.
The truth is that most people have been conditioned by lies and the media to be afraid of HEALTHY amounts of radiation! If the true health risks were given the media coverage they deserve then the multi-billion dollar radiation protection industry would be destroyed. We spend billions of dollars annually to "clean up" radoactive materials with levels already so low that the would only be healthy for people.
Tesla's radio used amplitude modulation (AM) a fairly obvious type of modulation. Frequency Modulation (FM) is quite a different animal as far as how the signal is encoded and FM is relatively immune to many of the problems that plague AM radio.
Either she doesn't mind existing or she does. Those are two possibilities and he's betting on one of them. Certainly not a completely pointless statement unless you're just a wee bit clueless.
Yes, I'm very familiar with vehicle drive trains, but thanks for pointing that out anyway. Please not though that the GP was clearly talking about a required drivetrain of "belt...chain...gears...something"
Again, from the article, I'm pretty sure they're talking about multi-wheel direct drive - no differential or transmission, etc.
Slashdot Mirror
Yes, and you're going to provide thrust to your spacecraft without affecting the asteroid exactly how?
Assuming a spherical iron asteroid with a 100m radius (the article mentions two football fields across) and a 20 ton ship you can provide a maximum gravitational force of about 1 pound. This is find and dandy and could provide a deflection of nearly the diameter of the earth over a decade period.
But...
The problem is how to produce that required force on your ship without impacting the asteroid. Conventional rockets or ion thrusters would necessarily be directed in the direction of the asteroid which would nullify any net force on the system (ship+asteroid). If you get enough distance between the asteroid and the ship so yout thrust can miss the asteroid and provide a net force, the force you can provide on the asteroid due to gravity drops as the square of the distance and becomes unusably low. You'd need litterally centuries or millenia of advance warning!
If anyone has ideas how to avoid this problem, I'm all ears. :)
True enough, but logic statements can be true, false, or neither (ill-defined?). Particularly self-referential statements often fit the 'neither' category. It's the assumption that logic statements must be either true or false that lead to paradoxes. :)
Anyone for a fuzzy native type? ;)
Sorry to be pedantic, but the word 'illegal' does NOT imply a criminal violation. Illegal simply means that something is prohibited by law. It makes no distinction of criminal/civil law.
I agree with the rest of your statements though. :)
Sorry, you're wrong. Actually, I finally looked this up on google. The numbers must be UNIQUE decimal digits between 0 ant 9.
Actually, I finally looked this up on google. The numbers must be UNIQUE digits between 0 ant 9.
Thanks... that's what I get for reading slashdot late at night. ;)
SEND == 9552, MORE == 1005, MONEY == 10557
SEND == 9554, MORE == 1005, MONEY == 10559
SEND == 9553, MORE == 1005, MONEY == 10558
Do the letters each have to represent a UNIQUE decimal digit? ... or be non-zero? It also seems like a requirement to be unique can't be satisfied either, so what's missing here?
Yes. The term "identity theft" is also a ridiculous one. If someone uses my SSN to pretend to be me, they haven't "stolen" my identity. I'm still the exact same person I was before hand. The actual term I believe is "Criminal Impersonation".
You must be new here.
Sorry... my brain must have been off this morning. ;) I'll have to claim sleep deprivation and a cranky attitude from 5 days of a bad flu. ...and obviously a bit of cluelessness.
I think you're missing the point of all the other posters here: That the attacks would almost certainly be IMCOMPATIBLE. For example: Suppose an attack is found for SHA1 that is just like this one in nature. You seem to think that these two attacks can be used in conjunction with each other, but that just isn't the case. The modifications to extend the file while preserving SHA1 almost certainly WON'T preserve the MD5 stamp match previously created by the other attack. The same would be true in the reverse order. Bottome line: Even with attacks like this against both algorithms, if you're trying to use this on a file that gives both MD5 and SHA1, then you can't combine the attacks and create new files that match BOTH MD5 and SHA1 of the original. If you still don't understand this, please, please don't try to make a living in cryptography.
Generate 2^60 RPMs?
Then TRY to find one that matches the SHA1?
You're kidding, right?
Obviously you and I have far different ideas of what "computationally feasable" means.
No you can't. Not with the same MD5 as someone else's exe. Please RTFA before posting. The attack does NOT allow you to produce a file that matches another arbitrary file's MD5.
I don't see the problem... as long as they only arrest and sentence his in-game character for the "crime". ;)
The atomic age was just what it seemed. It saw the development of technologies from the Atomic Ramjet and Nuclear Rocket engines to Thermo-electric Generators that could run for decades. Fuel pellets the size of a marble that hold the energy equivalent of tens of thousands of gallons of hydrocarbon fuel. The technology to free ourselves from our dependence on foreign oil and the effects that dependence is wreaking on our economy.
That technology is all still here, but naive people like you have been deluded into believing that it was just a pipe dream. ;)
No, real the energy density limit is E=mc^2.
If idiots and bought-and-paid-for "scientists" hadn't worked so hard to kill off the atomic age we'd probably be all over the solar system by now.
The truth is that most people have been conditioned by lies and the media to be afraid of HEALTHY amounts of radiation! If the true health risks were given the media coverage they deserve then the multi-billion dollar radiation protection industry would be destroyed. We spend billions of dollars annually to "clean up" radoactive materials with levels already so low that the would only be healthy for people.
Read more here.
Tesla's radio used amplitude modulation (AM) a fairly obvious type of modulation. Frequency Modulation (FM) is quite a different animal as far as how the signal is encoded and FM is relatively immune to many of the problems that plague AM radio.
Either she doesn't mind existing or she does. Those are two possibilities and he's betting on one of them. Certainly not a completely pointless statement unless you're just a wee bit clueless.
No... they still retain the exclusive RIGHT to discribute the work. The infringer is doing so without any right.
Yes, and dont' forget the flywheel! ;) Again, these have nothing to do with the drive train.
Earth to pablo: We're discussing the DRIVE TRAIN. The gears you're speaking of do absolutely NOTHING to transmit the engine torque to the wheels.
Again, from the article, I'm pretty sure they're talking about multi-wheel direct drive - no differential or transmission, etc.