I think the point is that Microsoft doesn't sell whole computer systems. They just produce the OS and let others bundle it with their computers.
True, they make mice and joysticks and sell support too, but they don't make their money by bundling their OS with something else, like IBM, SUN, Apple, etc. They're the only company that can sell their OS separately and make a living on it.
Actually, there has been a hack to run MacOS on the Amiga computer, to bring the subject back on topic.
When the Amiga was already on it's decline (after Commodore went bankrupt, actually), there was a little piece of software that loaded a Mac ROM into memory, and booted a Mac partition or partition file off the hardddrive. It was very nifty and worked fairly well.
There were a lot of drawbacks, of course. Virtual memory didn't work. Since the Amiga display hardware was so different from Apple's (and anyobdy else's), everything but monochrome was painfully slow. (This could be made to work better by installing a new graphics card in your Amiga, but these were prohibitively expensive.)
And the guy making all this possible, wrote the program just for his own amusement, and was surprised at how many people wanted it. So it's actually possible to run old 68000 based Mac programs on a quite ordinary Amiga 1200, with a software-only solution.
"It also said that Apple had hired those two guys [who got MacOS to boot on an IBM PowerPC machine]... apparently because they were so smart or something."
Hehehe... because they were so smart they posed a threat to Apple, perhaps?
"And as as we've seen with Microsoft [microsoft.com], operating systems companies don't make much money."
As someone else pointed out, Microsoft is an extreme exception. It's got about 95% market share on the desktop market, so it can sell a lot of copies of the same software package to make up for their development costs.
Apple has less then five percent market share. It's much harder for them to recover their development costs by selling only software.
Well, I'll probably be modded down for this, but isn't there a possibility that Linux will be obsolete one day when OS research has progressed far enough?
For instance, if parallel computers requires the kernel to be multithreaded in order to run efficiently on the new hardware.
Of course, you can keep the POSIX API to keep the OS backwards compatible, while replacing the kernel architecture, but then you can as well run BSD and call it Linux.
Maybe BSD or HURD will replace Linux. GNU may live on indefinitely, even if Linux dies, though.
"Just like when I XOR two streams of data together they take no more space than one stream?"
Yes, but the second stream consists of random numbers, and the same random numbers are generated at both the sending and receiving end. (Except that it's an analog noise signal, not random numbers.)
"Assuming the waves are assembled constructively, receiving them in the same bandwidth requires double the signal/noise ratio that receiving one wave would require, because your equipment needs to be just as sensitive but handle twice the signal amplitude."
The carrier wave doesn't have to contain more data than the original wave, so you can just modulate the amplitude down to what it was originally.
The original thing about the "invention" is that the (almost) random noise signal is generated by chaotic systems at the sending and receiving ends, respectively, so it's practically impossible for an outside eavesdropper to predict it. The two chaotic systems at both ends, however, are kept in sync.
And you don't need that much data to keep the two chaotic systems in sync. They only need to report their macroscopic states to eachother to keep in sync, not down to the last decimal.
"How is this technique any different? You still have to communicate the initial state of the noise source before you can communicate, just like PRNG stream cyphers."
The difference is that you don't have a preset key for the cypher. The "key" (actually an analog noise signal, not a digital key) is generated dynamically by two chaotic systems (with lasers), one at the sending and one at the receiving end.
The nice thing about chaotic systems is that a very miniscule difference in input produces wildly different outputs. You can only know the physical state of the system down to so many decimals. Sooner or later, microscopic differences in the input makes two chaotic systems behave very differently after a while, producing completely different outputs.
Even if the eavesdropper knew the state of the chaotic system down to 20 decimal places, and set up his own chaotic system to simulate the first two, it would very soon diverge, since differences in the 21st decimal place would propagate up to the macro level.
The guy in the article apparently came up with a way to synchronize the chaotic systems at the sending and receiving end, so they generate the same noise signal (the "same sequence of keys", if this had been digital encryption).
The only way for the eavesdropper to keep his own chaotic system in sync with the ones at the sending and receiving end, would be to interfer with them, and that must be much harder than just passively listening to the signal and then trying to decrypt it.
Note: This has nothing to do with quantum mechanics. Chaos arises in all complex, natural systems, and you don't need quantum mechanics to superimpose two waves.
Of course, you need quantum mechanics to build lasers, but that's just an implementation detail. You could, theoretically, use a system of water pumps to generate the chaotic signal and communicate through water waves.
The math is a little beyond me , but I got the part about the Rissanen limit being dependent on the class of input you have. Thanks for the explanation.
Do you have any idea how these compression algorithms fare on typical realworld input, like text, executables and graphic images?
"For a while, apple had the right idea. They tried IBM's strategy of making the platform open, then they chicken shitted out and went back to making their own boxes. [...] Why apple did an about face on this issue I will never know."
I think they faced the same problem as Palm Computing Inc. faces today: they couldn't make enough money on just selling the OS.
Sure, allowing other vendors to sell Macintosh hardware would have given MacOS a greater market share, but that doesn't mean it would have been economically viable for Apple Inc. In the end, it's the profit that counts for a company, not market share.
Making all parts of a computer system (box, motherboard, assembly, operating system, installation) is a form of vertical integration.
It's a classic way of increasing profit for a corporation. There's a small profit in each of the steps of making a computer: the company making the motherboard makes a small profit, the company making the OS makes a small profit, the company assembling the system and installing the OS makes a small profit, and so on. By taking care of all these steps, a company can put all these little profits under one roof, and increase the profit margin, using their organization and economies of scale.
That's probably the reason Apple never released an Intel x86 compatible version of MacOS. It would have been too easy for competitiors to make clones, and too easy for user to upgrade their hardware without buying from Apple. Apple would be stuck with the high cost of developing the OS (and there's a LOT of development money going into it), without making money on the hardware.
The same problem faces the Amiga. There will, most likely, only be ONE company selling Amiga computers. Developing an operating system is so expensive, and the market is so small, they won't be able to survive without the money from selling the hardware.
Unless, of course, the AmigaOS will be some kind of Open Source and gain enough followers...
But this appeared in Corel Linux a long time ago... (or was it Caldera OpenLinux?).
Re:Asymptotic rate is not good enough.
on
Optical Cryptography
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· Score: 1, Insightful
Ok...
So you're saying Rissanen gave the theoretical limit for how quickly a compression algorithm asymptotically approaches maximum entropy in its output, and Context Tree Weighing and other algorithms actually reach that limit?
Or is this only proven for certain classes of input, like Markov models?
Re:Use BWT instead of LZ for even more diffusion
on
Optical Cryptography
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· Score: 0
But I thought Lempel and Ziv, the creators of the LZ algorithm, proved that it was at least as efficient as any other algorithm given a sufficiently large amount of data to be comrpessed.
Are there really any other compression schemes that are essentially better?
Well, for that to work, you have to know what signal is used to mask the original signal.
Apparently this guy came up with a way to generate the *same* noise in two chaotic systems that are kept in sync with eachother -- so the noise (the "sequence of random numbers") isn't predetermined.
Ingenious.
Re:No chaotic communication is *not* a one time pa
on
Optical Cryptography
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· Score: 1, Interesting
That is very interesting, mbkennel.
So you mean there is a chaotic system A at the sender's end, and another chaotic system B at the receiver's end, of the same type?
And that they would diverge if left to themselves, but are continously synchronized with each other, so both A and B generate approximately the same signal (the same "sequence of encryption keys", if this had been digital encryption).
And that an eavesdropper, with his own chaotic system C, cannot synchronize it with A and B?
One Time Pad? Does that mean an encryption key that is only used once?
Re:Seems like a waste of noise...
on
Optical Cryptography
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· Score: 1, Informative
Yes, I assume the two waves occupy the same portion of the spectrum, otherwise the whole idea of hiding the signal behind noise is wasted. The noise has to overlap the signal. The signal doesn't necessarily have to overlap the noise, though.
Re:Nope: You've just given the bad guy your key.
on
Optical Cryptography
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· Score: 0
Yes, public key encryption is the best solution, unless you work for a security agency (or are so paranoid you believe you are:).
Well, if you use encryption or steganography on a computer, you have to utilize digital techniques, which is timeconsuming. Performance drops.
If you merely have to superimpose two lightwaves to steganize (sp?) a message, it all goes in realtime no matter how much bandwidth the lightwave carries. It's not a digital technique. It uses analog lightwaves.
So that technique can be used in e.g. optical fibres, so nobody can intercept messages by physically eavesdropping on the fibre. I don't think it's intended for home computers. It sounds more like a simple way for telephone companies to protect all the data in optic fibres without going in and encrypting the individual IP packages and such.
Re:Nope: You've just given the bad guy your key.
on
Optical Cryptography
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· Score: 0
I think that's a very good idea, quantaman (making cracking attempts harder by sending a lot of fake messages).
Of course, it wastes bandwidth, and somebody may be downloading the messages with a modem...;)
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I think the point is that Microsoft doesn't sell whole computer systems. They just produce the OS and let others bundle it with their computers.
True, they make mice and joysticks and sell support too, but they don't make their money by bundling their OS with something else, like IBM, SUN, Apple, etc. They're the only company that can sell their OS separately and make a living on it.
Actually, there has been a hack to run MacOS on the Amiga computer, to bring the subject back on topic.
When the Amiga was already on it's decline (after Commodore went bankrupt, actually), there was a little piece of software that loaded a Mac ROM into memory, and booted a Mac partition or partition file off the hardddrive. It was very nifty and worked fairly well.
There were a lot of drawbacks, of course. Virtual memory didn't work. Since the Amiga display hardware was so different from Apple's (and anyobdy else's), everything but monochrome was painfully slow. (This could be made to work better by installing a new graphics card in your Amiga, but these were prohibitively expensive.)
And the guy making all this possible, wrote the program just for his own amusement, and was surprised at how many people wanted it. So it's actually possible to run old 68000 based Mac programs on a quite ordinary Amiga 1200, with a software-only solution.
Hehehe... because they were so smart they posed a threat to Apple, perhaps?
"And as as we've seen with Microsoft [microsoft.com], operating systems companies don't make much money."
As someone else pointed out, Microsoft is an extreme exception. It's got about 95% market share on the desktop market, so it can sell a lot of copies of the same software package to make up for their development costs.
Apple has less then five percent market share. It's much harder for them to recover their development costs by selling only software.
Well, I'll probably be modded down for this, but isn't there a possibility that Linux will be obsolete one day when OS research has progressed far enough?
For instance, if parallel computers requires the kernel to be multithreaded in order to run efficiently on the new hardware.
Of course, you can keep the POSIX API to keep the OS backwards compatible, while replacing the kernel architecture, but then you can as well run BSD and call it Linux.
Maybe BSD or HURD will replace Linux. GNU may live on indefinitely, even if Linux dies, though.
Yes, but the second stream consists of random numbers, and the same random numbers are generated at both the sending and receiving end. (Except that it's an analog noise signal, not random numbers.)
"Assuming the waves are assembled constructively, receiving them in the same bandwidth requires double the signal/noise ratio that receiving one wave would require, because your equipment needs to be just as sensitive but handle twice the signal amplitude."
The carrier wave doesn't have to contain more data than the original wave, so you can just modulate the amplitude down to what it was originally.
The original thing about the "invention" is that the (almost) random noise signal is generated by chaotic systems at the sending and receiving ends, respectively, so it's practically impossible for an outside eavesdropper to predict it. The two chaotic systems at both ends, however, are kept in sync.
And you don't need that much data to keep the two chaotic systems in sync. They only need to report their macroscopic states to eachother to keep in sync, not down to the last decimal.
The difference is that you don't have a preset key for the cypher. The "key" (actually an analog noise signal, not a digital key) is generated dynamically by two chaotic systems (with lasers), one at the sending and one at the receiving end.
The nice thing about chaotic systems is that a very miniscule difference in input produces wildly different outputs. You can only know the physical state of the system down to so many decimals. Sooner or later, microscopic differences in the input makes two chaotic systems behave very differently after a while, producing completely different outputs.
Even if the eavesdropper knew the state of the chaotic system down to 20 decimal places, and set up his own chaotic system to simulate the first two, it would very soon diverge, since differences in the 21st decimal place would propagate up to the macro level.
The guy in the article apparently came up with a way to synchronize the chaotic systems at the sending and receiving end, so they generate the same noise signal (the "same sequence of keys", if this had been digital encryption).
The only way for the eavesdropper to keep his own chaotic system in sync with the ones at the sending and receiving end, would be to interfer with them, and that must be much harder than just passively listening to the signal and then trying to decrypt it.
Note: This has nothing to do with quantum mechanics. Chaos arises in all complex, natural systems, and you don't need quantum mechanics to superimpose two waves. Of course, you need quantum mechanics to build lasers, but that's just an implementation detail. You could, theoretically, use a system of water pumps to generate the chaotic signal and communicate through water waves.
No, I didn't mean "security firm". I meant a security agency like CIA or MOSAD.
128-bit public key encryption might not be enough for their secret messages.
I put you among my Friends just for mentioning Haskell.
And I thank God that there isn't any programming language based on the Turing machine.
No, wait, there is... Assembler!
The math is a little beyond me , but I got the part about the Rissanen limit being dependent on the class of input you have. Thanks for the explanation.
Do you have any idea how these compression algorithms fare on typical realworld input, like text, executables and graphic images?
I think they faced the same problem as Palm Computing Inc. faces today: they couldn't make enough money on just selling the OS.
Sure, allowing other vendors to sell Macintosh hardware would have given MacOS a greater market share, but that doesn't mean it would have been economically viable for Apple Inc. In the end, it's the profit that counts for a company, not market share.
Making all parts of a computer system (box, motherboard, assembly, operating system, installation) is a form of vertical integration.
It's a classic way of increasing profit for a corporation. There's a small profit in each of the steps of making a computer: the company making the motherboard makes a small profit, the company making the OS makes a small profit, the company assembling the system and installing the OS makes a small profit, and so on. By taking care of all these steps, a company can put all these little profits under one roof, and increase the profit margin, using their organization and economies of scale.
That's probably the reason Apple never released an Intel x86 compatible version of MacOS. It would have been too easy for competitiors to make clones, and too easy for user to upgrade their hardware without buying from Apple. Apple would be stuck with the high cost of developing the OS (and there's a LOT of development money going into it), without making money on the hardware.
The same problem faces the Amiga. There will, most likely, only be ONE company selling Amiga computers. Developing an operating system is so expensive, and the market is so small, they won't be able to survive without the money from selling the hardware.
Unless, of course, the AmigaOS will be some kind of Open Source and gain enough followers...
Nah -- not among Linux users.
But this appeared in Corel Linux a long time ago... (or was it Caldera OpenLinux?).
Ok...
So you're saying Rissanen gave the theoretical limit for how quickly a compression algorithm asymptotically approaches maximum entropy in its output, and Context Tree Weighing and other algorithms actually reach that limit?
Or is this only proven for certain classes of input, like Markov models?
But I thought Lempel and Ziv, the creators of the LZ algorithm, proved that it was at least as efficient as any other algorithm given a sufficiently large amount of data to be comrpessed.
Are there really any other compression schemes that are essentially better?
I see. "Security through obscurity" relies on the the cracker's lack of competence, not mathematical methods, like ordinary public key encryption.
How does one hide messages in reandom noise, though? Would it work to LZ-compress them, to make them appear random?
Well, for that to work, you have to know what signal is used to mask the original signal.
Apparently this guy came up with a way to generate the *same* noise in two chaotic systems that are kept in sync with eachother -- so the noise (the "sequence of random numbers") isn't predetermined.
Ingenious.
That is very interesting, mbkennel.
So you mean there is a chaotic system A at the sender's end, and another chaotic system B at the receiver's end, of the same type?
And that they would diverge if left to themselves, but are continously synchronized with each other, so both A and B generate approximately the same signal (the same "sequence of encryption keys", if this had been digital encryption).
And that an eavesdropper, with his own chaotic system C, cannot synchronize it with A and B?
Chaotic doesn't equal random. There are algorithms for creating chaotic signals. How else would we generate the Mandelbrot set?
One Time Pad?
Does that mean an encryption key that is only used once?
Yes, I assume the two waves occupy the same portion of the spectrum, otherwise the whole idea of hiding the signal behind noise is wasted. The noise has to overlap the signal. The signal doesn't necessarily have to overlap the noise, though.
Yes, public key encryption is the best solution, unless you work for a security agency (or are so paranoid you believe you are :).
Hm... I don't think it's any more "security through obscurity" than PGP is.
Well, if you use encryption or steganography on a computer, you have to utilize digital techniques, which is timeconsuming. Performance drops.
If you merely have to superimpose two lightwaves to steganize (sp?) a message, it all goes in realtime no matter how much bandwidth the lightwave carries.
It's not a digital technique. It uses analog lightwaves.
So that technique can be used in e.g. optical fibres, so nobody can intercept messages by physically eavesdropping on the fibre.
I don't think it's intended for home computers. It sounds more like a simple way for telephone companies to protect all the data in optic fibres without going in and encrypting the individual IP packages and such.
I think that's a very good idea, quantaman (making cracking attempts harder by sending a lot of fake messages).
;)
Of course, it wastes bandwidth, and somebody may be downloading the messages with a modem...