to intercept the signal, you simply tap the fiber and split a small portion of the beam into your copy of their device.
their "descrambling" method doesn't sound hard - you take the light you receive and send half through a delay loop equal to one circuit through the originating ring laser. then you compare the two signals to obtain the data.
the only eavesdropper this will thrwart is the guy who uses only intensity (and not polarization) measurements. communication using "Polaritons" has been around for a while.
the easy way is to put your light through an birefringent crystal and modulate the input voltage - this produces a change in the polarization you can read out with a simple polarizer. the problem is, when you try to change the phase on a photon fast (like for data transfer), you screw up the frequency. and by screwing up the frequency you reduce the gain of your doped fiber amplifiers and you crowd signal space for other colors (although not much, admittedly).
conclusion: this is useless for sending obscure data. hiding your data in noise is useless if everyone knows how to remove the noise.
I have an ATI PCI TV Wonder, and the card has worked great for me. It worked on Win98, and now works on Win2K, under two difference Athlon processors.
I have had some hardware issues, and always suspected the TV Wonder, but in the end that was never the case.
Updated TV Wonder drivers are indeed available from ATI, and if you can manage to follow the needlessly complex driver install instructions, the card works without even rebooting!
The image quality is great, and the capture works just fine. Cyberlink PowerVCR 3 is much better than the crap MultiMediaCenter that comes with the card, but at least the drivers are fine.
So if your card is sitting unused in a drawer somewhere, and you're running Win2K, fire up the new drivers and give it a try.
there are many tools which allow you to hide things in images. there is already "Steganotools" (i forget the website) and programs like "Camoflage" that hide files inside of other files, or append them on the end as junk.
if you really want secrecy, you can move to things like "DriveCrypt", which makes containers you can mount as new drives. but these containers have no header, and being compressed and encrypted, it's impossible to distinguish them from purely random data unless you know the strong passphrase.
the idea of hiding data in the LSB of pictures (or mp3's for that matter) is old. just better hope that no one else has a copy of the original file! if you choose specific pictures where the LSB is statistically random enough, there is nothing that says you can't hide data there securely. the simplest way for short messages is to run MD5 (or some other hash) on your passphrase, and XOR the resulting digest on your message to produce your cyphertext. then just replace the LSB's in your image file.
just make sure you replace all your LSB's or else an attacker can detect that there is something hidden.
the only thing new about this particular tool is that it uses a browser plugin to decrypt the picture by double clicking on it. that sounds insecure to me.
drivecrypt lets you install the program entirely on removable media, so you don't have strange stego tools installed on your computer when the Red Police come busting down your door...
The "Black Light Energy" or "Zero Point Energy" hoax has been around for a long time.
Basically, the crackpot theory says that, "Well, if Hydrogen in the n=1 state has an energy of -13.6eV, and if energy goes as 1/n^2, then if I make n=1/2, that's 30.8 eV per hydrogen in free energy!!"
That's all this theory is, folks, I promise.
This is impossible. Why don't we see this energy signature anywhere in nature? How would the energy get back into the Hydrogen atom? What's to prevent the atom from collapsing into n=1/(infinity). If I can make n (the energy level) arbitrarily close to zero, I can get an infinite amotn of energy out of each atom!
It's kinda like tying a marble to a string and dropping it to a black hole - i can get infinite energy by tying the string to a generator. Except in the caser of hydrogen it's actually not possible.
The uncertaintly principle is a well proved physical theory that would have to be seriously (and impossibly) violated for this guy's crackpot theories to work.
I have psuedo-responsibility for our tiny network of about 15 computers. So some jackass has to use Outlook to sync his email with his expensive handheld, and he gets nailed by Klez.
So Klez works even by simply previewing the message and launches itself. It has its own mail sending engine, and forges the From: field to look like it's real. It also copies past Subject: fields to fool the recipient.
But this time, our little friend Klez has brought his little friend Elkern32. This nasty little guy infects executables on the infected computer, and is also network aware and infects files across the network. So even people who didn't use Outlook were infected. Some people had hundreds of infected programs on their computer.
And a cool thing about Elkern is that it can randomly overwrite a files bytes with all zeroes, while maintaining the file length. It can be nasty.
All this because no one updates their virus definitions.
In this experiment, tiny drops of oil are suspended in mid-air between two charged plates by the interaction of a discrete electric charge on the oil drop.
You use a microscope to measure the speed of the drop with no charge on the plates, then adjust the charge on the plates to hold the drop in place. In other words, the force of gravity is cancelled by the electrostatic force.
If the drops are small enough, you can notice discrete steps in the data when you plot the variables. The beauty is in its simplicity: Using some oil, two pieces of metal and microscope, you can determing the charge of a single electron.
i built a water CPU cooler for $20 out of pocket costs. of course, that doesn't count the stuff i stole from work.:) it's a machined copper slug, a reservoir, and a $20 aquarium pump.
if you turn the thing on with a cool reservoir, the CPU temp stays below 76F. but after being on for 10 hours, the reservoir temperature raises to about 113F due to my lack of money to buy a real radiator. so my equilibrium CPU temp with an Athlon XP 1600 is 123F, when the fan it came with ran it at 145F.
granted, copper slugs and machining equipment and "free" swagelock (and peltiers!) is not something everyone has, but use what you got, right?
hope someone finds it useful or interesting.
muerte
Not Stopped For So Long...
on
Stopping Light
·
· Score: 2, Informative
before everyone gets all excited, please keep in mind that the light pulse could only be stopped for something on the order of 100ms. the information about the light pulse is stored in the spin state of the atoms, which are told to release the information by another, perpendicular, laser beam.
but this phase information is quickly lost as the atoms move around in a thermal equilibrium. think about it as sky-writing. the information is written there, but as the particles move around the infomatino is quickly lost.
most of these experiments have been done with UltraCold atom clouds, and the most recent ones (presented at DAMOP last year) were done in Bose-Einstein Condensates.
due to the very short "coherence time", this phenomena is most likely not very useful for quantum computing.
the buzzwords to look for when it comes to quantum computers (i.e. the things most likely to work) are "trapped ions" and "optical lattices". i promise, one of those two will be used in the first functional quantum computer.
here at MIT BEC, the webserver is a mid-power pentium that WAS runing win2k professional with IIS. but of course i get a call at 8:30 am (i'm a grad student i sleep late) with someone yelling "THE WEBSERVER ISN'T WORKING".
that was because it was some dumbed down version of IIS that limited the connections to 10, and no one around here cares enough about windows to figure out the right registry settings (me neither).
so instead of fixing it i downloaded apache and configged it in about 5 minutes. maybe less.
since then it appears that web browsing has been a bit smoother. i checked the web log, which is normally about 200k on any given day, but by 4pm today is had grown to 17 MEGABYTES. ha! at it's peak we were serving around 10 megabytes per minute in pdfs, jpegs, etc. we have served 1.7 gigs so far today. whew.
so now that it's fixed, come on in and check it out. go to ketterle, then research, and especially check out rubidium.:)
and while i'm here, let me just say that wolfgang ketterle is one of the nicest people i have ever worked for. he, and everyone else here at MIT just kicks ass. wolfgang had gone to bed at 2:30am last night, and was awoken at 5:30am by some strange swedish dude...
i have a TiPB with 128 mb ram also, and i don't have problems putting it to sleep. as long as the pmud daemon actually loads (sometimes it doesn't ???), if you close the lid or type 'apm' in a shell, it goes to sleep.
and he complains about using batmon to monitor the battery. batmon? jeez. try the APM module for gkrellm and get with the times.:)
i just used my PB on a plane flight from boston to sweden, and it was great. the only problem is that it's a little _too_ big to use in those darn British Airways seats!!! the person in front of me reclined and almost snapped my display in half.:(
as for as yellowdog goes, i agree that it's great. i can't believe that they "recommend" tthe "dekstop user" install, as it doesn't even include gcc!!! i had tot uninstall and reinstall with the developer's workstation.
one thing that it doesn't have that i missed was linuxconf (and when i try tto compile it is is missing 'crypt'? what's that?). but i suppose that webmin does everything that linuxconf used to do.
on the extras cd they also include Mac On Linux. now _that_ is cool. i run OS9.1 in a little window in enlightenment. if you change the screen res inside the mac OS it actually resizes the window! well, at least i thought it was cool. the only problem is that when you wantt to change (or insert) CDs, you have to reboot the macos.
before yellowdog i had been using OSX, and i was SO tired of using buggy apps and a piss slow GUI that i was incredibly relieved when my x server startted for the first time.
all you mac users out there, give it a try. good job yellowdog!
(a) He has fudged his data or left out some important part of his apparatus.
(b) He has discovered something important.
Not having been published in a peer reviewed journal, and having no physical collaboration from independent observers (his co-author never actually participated in the experiment), I would have to lean toward choice (a).
His experimental apparatus is also very home grown. What does he mean that he couldn't "get a good enough vacuum to prevent condensation on the superconductor" ??? His home brew method to manufacture his SC coating looks EZ Bake style to me also.
However, if his experiment and results are God's honest truth, there are some interesting implications.
He says that he measured the force on pendulums of ceramic, wood, rubber, etc hanging from cotton strings seperated from his spark discharge machine by distances of SIX and ONE HUNDRED AND FIFTY meters, including walls and steel plates. One must not that he does not publish the results for the 150m experiment. His primary results are from a rubber sphere, and he doesn't explicitly publish any other data. However, he claims to have imparted about 2 milliJoules of energy into the ball about 20 feet away. That's a 1/2 ounce ball on a 30 inch string given enough kick to swing 6 inches. If this is correct, it really is truly amazing.
His writing style and lack of clarity also lead me to believe that his results do not speak for themselves.
Once we get some replication of his setup, then we can see for ourselves. Nobel Prize - or Cold Fusion.
what a sexy piece of hardware. it's so thin, and the screen is so big! it also really does last almost five hours on a battery. 256 megs of ram and a 20 gig hard drive with a 500 mhz processor. sure, it cost a freaking ton, but i didn't pay for it.
i finally ditched the mac install for a YellowDog Linux setup, and i am much happier. i boot MacOnLinux in a little window which still impresses me. if you change the desktop resolution inside the mac os, it actually resizes the little window! freaking rad.
i think it's cool when people see the mac and expect some schmuck playing with Hypercard or something, and instead i'm coding something and running Enlightenment.
if you can get your employer to spring for it, i highly recommend it.
at lund university in sweden there is a group that is using high speed lasers to actually take pictures of the combustion process in engines. they are working with volvo to achieve the same goals talked about in the header here - reduced emmissions and increased efficiency.
when i visited the lab there a guy explained it to me:
1: make a mockup cylinder with a glass viewport (!!!). 2: use a laser that emits pulses on a femtosecond time scale. 3: shine the laser on a spinning mirror. 4: shine the result (absorbtion image) on a very high speed digital camera.
the result is a crystal clear picture of the fluid dynamics of the combustion process at any given microsecond. they say that this technique gives much better resolution than finite element analysis because of the incredible computational power needed to analyze the fluid dynamics in even largish (~5mm) chunks.
it doesn't always pay to simulate what you can take pictures of...
the report says they are using RF, which makes it easier to detect the signal from up close (no LOS), but the signal is harder to pick up from farther away.
one easy way to make a pretty secure connection would be to make little enigma-esque scrambler wheels on the keyboard and base station. since the number of intercepted characters is probably low, your key length doesn't have to be outrageous to provide some security.
another way is to, every couple hours or so, prompt the user to type a special, newly generated word or two into the keyboard. the computer makes up the words, puts them to the screen, and tells the keyboard to stop transmitting. then the keyboard uses the typed in phrase for a new cryptographic key and begins transmitting again. it won't work with current models, but it would be a fairly robust system for newer models.
they are beaming an easily detectable infrared signal from a fairly strong LED. if your keyboard has to be a palm pilotesque 3 feet from your receiver which has a lens/detector about 1/8" across, that means that if i have a mirror/detector about a foot in diameter i can get the same signal strength from almost 300 feet away. barring dust, humidity, etc, etc.
what's _really_ scary is the TEMPEST style attatcks. where the RF from your monitor can be received and reproduced from hundreds of feet away. look around on the web for TEMPEST stuff. the _only_ way to protect yourself from being sniffed in that manner is to encase the whole room in copper. as in a copper door that seals on a copper frame, etc. the bright side is that the attacker needs fairly sophisticated and expensive equipment to be able to do this.
going back to the logitech wireless thing, i think there is a way to defeat the more casual sniffers. if the base station continuously transmits a sort of "key" back to the mouse/keyboard, it is _very_ improbably that the attecker has a good enough Line Of Sight to be able to intercept both signals, and then do distinguish the two. it doesn't have to be any kind of complicated cypher, just an additive digital key.
why doesn't somebody program a palm pilot to sniff digital keys? just use some eyeglasses and a holder and you could pick up signals from (2 /.125 * 3 =) 50 feet away.
muerte
speaking then of digital keys, someday microsoft will enforce digital rights management on my keyboard. it will have to negotiate a session on my computer, then i will have to sign a lengthy agreement that i won't type in any copyrighted text.
since i am too lazy to turn java on and off, maybe they can put geocities (or whoever) on the RTBL so that when i mistakenly click on blind links i am not immediately whisked away to a pr0n popup hell.
...or maybe i just shouldn't surf sites that would lead me down blind links in the first place.
and why the heck isn't AOL on the list? seems like every other piece of spam i get is from some AOL ip, and no one i care about uses that schwag...
...or maybe i could get off my lazy butt and set up my filtering right.
in any case, i think that it's a good strategy to block certain high profile WWW sites if their apathy is causing me to waste my time sorting mail. however, this system does lend itself towards abuse.
with all of these people running fancy chillers, etc, etc, i have to wonder if all their cooling power is really worth it.
since most people don't want water dripping around, cooling systems should keep the chip above the dew point. usually less than 50-60 degrees F or so. and also keep the chip cooler than, say (ouch) 150 degrees F or so.
all this, and the processor makes about, as an insane maximum number, 100 watts of heat.
now what happens if you take a 100 watt lightbulb and put it in a box about 20cm on a side. thermodynamics says that the box will be about 130 degrees on its surface, assuming an 80 degree room. so that means if you can transfer all your processors heat to the surface of a box about 8 inches on a side, the result will be an equilibrium of about 130 degrees F. (sorry for mixing metric and standard, just trying to use _some_ recognizable numbers).
so now just use a chimney. attach a small copper block to your cpu and drill a hole or somehow attach a hose passing through the block _vertically_. give about 6 inches or so above the block for good thermal convection. run both of those tubes into a 8 inch box filled with water (uninsulated as possible).
the water will naturally circulate due to heating from the chip and recycle to the reservoir.
upon further calculation, if you have a tube about 1 cm in diameter and a convection style flow rate of, say, 1 cm (or ml) per second, the exit temperature of the water (and hence the cpu heat) is about 50 degrees F hotter than the input. that's bad!!! almost boiling, and certainly disappointing.
so you must have pump to provide at least 10 ml/sec of flow to keep the heat to only +5 deg F. i would think that any fish tank style pump could do that cheap.
anyways, i was hoping to show that pumps were unnecessary, but instead all i can say that a _chiller_ is pretty much a waste of money. (ps. doubling the surface area of the reservoir reduces the delta T by a factor of 2, etc)
i hope that someone has found this little bit of physics interesting.
Slashdot Mirror
their "descrambling" method doesn't sound hard - you take the light you receive and send half through a delay loop equal to one circuit through the originating ring laser. then you compare the two signals to obtain the data.
the only eavesdropper this will thrwart is the guy who uses only intensity (and not polarization) measurements. communication using "Polaritons" has been around for a while.
the easy way is to put your light through an birefringent crystal and modulate the input voltage - this produces a change in the polarization you can read out with a simple polarizer. the problem is, when you try to change the phase on a photon fast (like for data transfer), you screw up the frequency. and by screwing up the frequency you reduce the gain of your doped fiber amplifiers and you crowd signal space for other colors (although not much, admittedly).
conclusion: this is useless for sending obscure data. hiding your data in noise is useless if everyone knows how to remove the noise.
muerte
I have had some hardware issues, and always suspected the TV Wonder, but in the end that was never the case.
Updated TV Wonder drivers are indeed available from ATI, and if you can manage to follow the needlessly complex driver install instructions, the card works without even rebooting!
The image quality is great, and the capture works just fine. Cyberlink PowerVCR 3 is much better than the crap MultiMediaCenter that comes with the card, but at least the drivers are fine.
So if your card is sitting unused in a drawer somewhere, and you're running Win2K, fire up the new drivers and give it a try.
muerte
if you really want secrecy, you can move to things like "DriveCrypt", which makes containers you can mount as new drives. but these containers have no header, and being compressed and encrypted, it's impossible to distinguish them from purely random data unless you know the strong passphrase.
the idea of hiding data in the LSB of pictures (or mp3's for that matter) is old. just better hope that no one else has a copy of the original file! if you choose specific pictures where the LSB is statistically random enough, there is nothing that says you can't hide data there securely. the simplest way for short messages is to run MD5 (or some other hash) on your passphrase, and XOR the resulting digest on your message to produce your cyphertext. then just replace the LSB's in your image file.
just make sure you replace all your LSB's or else an attacker can detect that there is something hidden.
the only thing new about this particular tool is that it uses a browser plugin to decrypt the picture by double clicking on it. that sounds insecure to me.
drivecrypt lets you install the program entirely on removable media, so you don't have strange stego tools installed on your computer when the Red Police come busting down your door...
just my $.02.
muerte
Basically, the crackpot theory says that, "Well, if Hydrogen in the n=1 state has an energy of -13.6eV, and if energy goes as 1/n^2, then if I make n=1/2, that's 30.8 eV per hydrogen in free energy!!"
That's all this theory is, folks, I promise.
This is impossible. Why don't we see this energy signature anywhere in nature? How would the energy get back into the Hydrogen atom? What's to prevent the atom from collapsing into n=1/(infinity). If I can make n (the energy level) arbitrarily close to zero, I can get an infinite amotn of energy out of each atom!
It's kinda like tying a marble to a string and dropping it to a black hole - i can get infinite energy by tying the string to a generator. Except in the caser of hydrogen it's actually not possible.
The uncertaintly principle is a well proved physical theory that would have to be seriously (and impossibly) violated for this guy's crackpot theories to work.
Maybe next time.
So Klez works even by simply previewing the message and launches itself. It has its own mail sending engine, and forges the From: field to look like it's real. It also copies past Subject: fields to fool the recipient.
But this time, our little friend Klez has brought his little friend Elkern32. This nasty little guy infects executables on the infected computer, and is also network aware and infects files across the network. So even people who didn't use Outlook were infected. Some people had hundreds of infected programs on their computer.
And a cool thing about Elkern is that it can randomly overwrite a files bytes with all zeroes, while maintaining the file length. It can be nasty.
All this because no one updates their virus definitions.
Muerte
In this experiment, tiny drops of oil are suspended in mid-air between two charged plates by the interaction of a discrete electric charge on the oil drop.
You use a microscope to measure the speed of the drop with no charge on the plates, then adjust the charge on the plates to hold the drop in place. In other words, the force of gravity is cancelled by the electrostatic force.
If the drops are small enough, you can notice discrete steps in the data when you plot the variables. The beauty is in its simplicity: Using some oil, two pieces of metal and microscope, you can determing the charge of a single electron.
It doesn't get much prettier than that.
Muerte
if you turn the thing on with a cool reservoir, the CPU temp stays below 76F. but after being on for 10 hours, the reservoir temperature raises to about 113F due to my lack of money to buy a real radiator. so my equilibrium CPU temp with an Athlon XP 1600 is 123F, when the fan it came with ran it at 145F.
you can see pictures and stuff here.
granted, copper slugs and machining equipment and "free" swagelock (and peltiers!) is not something everyone has, but use what you got, right?
hope someone finds it useful or interesting.
muerte
but this phase information is quickly lost as the atoms move around in a thermal equilibrium. think about it as sky-writing. the information is written there, but as the particles move around the infomatino is quickly lost.
most of these experiments have been done with UltraCold atom clouds, and the most recent ones (presented at DAMOP last year) were done in Bose-Einstein Condensates.
due to the very short "coherence time", this phenomena is most likely not very useful for quantum computing.
the buzzwords to look for when it comes to quantum computers (i.e. the things most likely to work) are "trapped ions" and "optical lattices". i promise, one of those two will be used in the first functional quantum computer.
muerte
that was because it was some dumbed down version of IIS that limited the connections to 10, and no one around here cares enough about windows to figure out the right registry settings (me neither).
so instead of fixing it i downloaded apache and configged it in about 5 minutes. maybe less.
since then it appears that web browsing has been a bit smoother. i checked the web log, which is normally about 200k on any given day, but by 4pm today is had grown to 17 MEGABYTES. ha! at it's peak we were serving around 10 megabytes per minute in pdfs, jpegs, etc. we have served 1.7 gigs so far today. whew.
so now that it's fixed, come on in and check it out. go to ketterle, then research, and especially check out rubidium.
and while i'm here, let me just say that wolfgang ketterle is one of the nicest people i have ever worked for. he, and everyone else here at MIT just kicks ass. wolfgang had gone to bed at 2:30am last night, and was awoken at 5:30am by some strange swedish dude...
later,
muerte
and he complains about using batmon to monitor the battery. batmon? jeez. try the APM module for gkrellm and get with the times. :)
i just used my PB on a plane flight from boston to sweden, and it was great. the only problem is that it's a little _too_ big to use in those darn British Airways seats!!! the person in front of me reclined and almost snapped my display in half. :(
as for as yellowdog goes, i agree that it's great. i can't believe that they "recommend" tthe "dekstop user" install, as it doesn't even include gcc!!! i had tot uninstall and reinstall with the developer's workstation.
one thing that it doesn't have that i missed was linuxconf (and when i try tto compile it is is missing 'crypt'? what's that?). but i suppose that webmin does everything that linuxconf used to do.
on the extras cd they also include Mac On Linux. now _that_ is cool. i run OS9.1 in a little window in enlightenment. if you change the screen res inside the mac OS it actually resizes the window! well, at least i thought it was cool. the only problem is that when you wantt to change (or insert) CDs, you have to reboot the macos.
before yellowdog i had been using OSX, and i was SO tired of using buggy apps and a piss slow GUI that i was incredibly relieved when my x server startted for the first time.
all you mac users out there, give it a try. good job yellowdog!
muerte
(a) No one else works there.
or
(b) He is the only one there that ever publishes.
I wanna be a crackpot and make my own institute! Then NASA will know where to send the grant money...
(a) He has fudged his data or left out some important part of his apparatus.
(b) He has discovered something important.
Not having been published in a peer reviewed journal, and having no physical collaboration from independent observers (his co-author never actually participated in the experiment), I would have to lean toward choice (a).
His experimental apparatus is also very home grown. What does he mean that he couldn't "get a good enough vacuum to prevent condensation on the superconductor" ??? His home brew method to manufacture his SC coating looks EZ Bake style to me also.
However, if his experiment and results are God's honest truth, there are some interesting implications.
He says that he measured the force on pendulums of ceramic, wood, rubber, etc hanging from cotton strings seperated from his spark discharge machine by distances of SIX and ONE HUNDRED AND FIFTY meters, including walls and steel plates. One must not that he does not publish the results for the 150m experiment. His primary results are from a rubber sphere, and he doesn't explicitly publish any other data. However, he claims to have imparted about 2 milliJoules of energy into the ball about 20 feet away. That's a 1/2 ounce ball on a 30 inch string given enough kick to swing 6 inches. If this is correct, it really is truly amazing.
His writing style and lack of clarity also lead me to believe that his results do not speak for themselves.
Once we get some replication of his setup, then we can see for ourselves. Nobel Prize - or Cold Fusion.
/Muerte
i finally ditched the mac install for a YellowDog Linux setup, and i am much happier. i boot MacOnLinux in a little window which still impresses me. if you change the desktop resolution inside the mac os, it actually resizes the little window! freaking rad.
i think it's cool when people see the mac and expect some schmuck playing with Hypercard or something, and instead i'm coding something and running Enlightenment.
if you can get your employer to spring for it, i highly recommend it.
muerte
when i visited the lab there a guy explained it to me:
1: make a mockup cylinder with a glass viewport (!!!).
2: use a laser that emits pulses on a femtosecond time scale.
3: shine the laser on a spinning mirror.
4: shine the result (absorbtion image) on a very high speed digital camera.
the result is a crystal clear picture of the fluid dynamics of the combustion process at any given microsecond. they say that this technique gives much better resolution than finite element analysis because of the incredible computational power needed to analyze the fluid dynamics in even largish (~5mm) chunks.
it doesn't always pay to simulate what you can take pictures of...
one easy way to make a pretty secure connection would be to make little enigma-esque scrambler wheels on the keyboard and base station. since the number of intercepted characters is probably low, your key length doesn't have to be outrageous to provide some security.
another way is to, every couple hours or so, prompt the user to type a special, newly generated word or two into the keyboard. the computer makes up the words, puts them to the screen, and tells the keyboard to stop transmitting. then the keyboard uses the typed in phrase for a new cryptographic key and begins transmitting again. it won't work with current models, but it would be a fairly robust system for newer models.
muerte
what's _really_ scary is the TEMPEST style attatcks. where the RF from your monitor can be received and reproduced from hundreds of feet away. look around on the web for TEMPEST stuff. the _only_ way to protect yourself from being sniffed in that manner is to encase the whole room in copper. as in a copper door that seals on a copper frame, etc. the bright side is that the attacker needs fairly sophisticated and expensive equipment to be able to do this.
going back to the logitech wireless thing, i think there is a way to defeat the more casual sniffers. if the base station continuously transmits a sort of "key" back to the mouse/keyboard, it is _very_ improbably that the attecker has a good enough Line Of Sight to be able to intercept both signals, and then do distinguish the two. it doesn't have to be any kind of complicated cypher, just an additive digital key.
why doesn't somebody program a palm pilot to sniff digital keys? just use some eyeglasses and a holder and you could pick up signals from (2 / .125 * 3 =) 50 feet away.
muerte
speaking then of digital keys, someday microsoft will enforce digital rights management on my keyboard. it will have to negotiate a session on my computer, then i will have to sign a lengthy agreement that i won't type in any copyrighted text.
and why the heck isn't AOL on the list? seems like every other piece of spam i get is from some AOL ip, and no one i care about uses that schwag...
...or maybe i could get off my lazy butt and set up my filtering right.
in any case, i think that it's a good strategy to block certain high profile WWW sites if their apathy is causing me to waste my time sorting mail. however, this system does lend itself towards abuse.
muerte
since most people don't want water dripping around, cooling systems should keep the chip above the dew point. usually less than 50-60 degrees F or so. and also keep the chip cooler than, say (ouch) 150 degrees F or so.
all this, and the processor makes about, as an insane maximum number, 100 watts of heat.
now what happens if you take a 100 watt lightbulb and put it in a box about 20cm on a side. thermodynamics says that the box will be about 130 degrees on its surface, assuming an 80 degree room. so that means if you can transfer all your processors heat to the surface of a box about 8 inches on a side, the result will be an equilibrium of about 130 degrees F. (sorry for mixing metric and standard, just trying to use _some_ recognizable numbers).
so now just use a chimney. attach a small copper block to your cpu and drill a hole or somehow attach a hose passing through the block _vertically_. give about 6 inches or so above the block for good thermal convection. run both of those tubes into a 8 inch box filled with water (uninsulated as possible).
the water will naturally circulate due to heating from the chip and recycle to the reservoir.
upon further calculation, if you have a tube about 1 cm in diameter and a convection style flow rate of, say, 1 cm (or ml) per second, the exit temperature of the water (and hence the cpu heat) is about 50 degrees F hotter than the input. that's bad!!! almost boiling, and certainly disappointing.
so you must have pump to provide at least 10 ml/sec of flow to keep the heat to only +5 deg F. i would think that any fish tank style pump could do that cheap.
anyways, i was hoping to show that pumps were unnecessary, but instead all i can say that a _chiller_ is pretty much a waste of money. (ps. doubling the surface area of the reservoir reduces the delta T by a factor of 2, etc)
i hope that someone has found this little bit of physics interesting.
muerte