Scientists develop first completely covert communication system with lasers:
As computing power continues to increase, previously unbreakable forms of encryption have crumbled. Now, though, we appear to be on the verge of what may be truly unbreakable quantum encryption. It's possible in the not too distant future no one will be able to spy on a message secured with these advanced methods no matter how long they hammer at it. Researchers are now looking to take things one step further and completely camouflage a message so no one even knows that a message was sent in the first place. If you can't even risk an eavesdropper knowing that a message has been sent, let alone what it says, you need a covert communication system. That's the idea at the heart of a new experiment conducted at the University of Massachusetts. Researchers there have developed a method of using photons to make a message invisible to everyone but the intended recipient.
The covert system relies on a technique called pulse position modulation, which is actually much more simple than you'd expect. It involves dividing a second, minute, or other unit of time into discrete bands, each of which correspond to a different letter or symbol. This code would have to be shared with the intended recipient ahead of time, which is perhaps the most notable flaw with the whole scheme. Once that's done, through, a series of pulses could be delivered like optical Morse code to convey a message.
http://www.extremetech.com/extreme/182142-scientis ts-develop-first-completely-covert-communication-s ystem-with-lasers
http://arxiv.org/abs/1404.7347
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For the first time in the history of quantum mechanics, scientists have been able to transmit a black and white image without having to send any physical particles. The phenomenon can be explained using the Zeno effect, the same effect that explains that movement itself is impossible.
The journal article is in Proceedings of the National Academy of Sciences of the United States of America (DOI: 10.1073/pnas.1614560114)
Wikipedia has an article about the quantum Zeno effect.
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Typing By Slamming Your Laptop Closed. Repeatedly:
Do you sometimes feel that your custom mechanical keyboard is not quite loud enough to proclaim your superior hacking powers? Or do you need a more forceful way shout in all caps at someone who is wrong on the internet? For all this and more, [Jesse Li] has got you covered, with a set of bash scripts that allows you to type by slamming your laptop closed repeatedly, using Morse code.
The scripts are quite simple, and work receiving the lid open/close events from ACPI (Advanced Configuration and Power Interface), recording the open and close timestamp and converting the timing to dots and dashes. After slamming to the required rhythm, you keep the lid open to see the character appear.
Yes, I see no practical use for this. Yes, I think it is a neat "hack". Had an itch and scratched it. Any soylentils here done their own Morse transceiver? How about on your smart phone? Transmit by long- or short-press anywhere on the screen for dits and dahs. Receive by phone vibration. Nearly silent communication while never needing to look at the screen!
Previously:
(2020-02-29) Learning Morse Code The Ludwig Koch Way
(2016-06-22) Ham it up! 2016 ARRL Field Day is June 25-26
(2015-02-27) Verizon Issues Furious Response to FCC, in Morse Code, Dated 1934
(2014-05-11) First Covert Communication System with Lasers
(2014-04-03) The POW Who Blinked "Torture" In Morse Code
(Score: 2) by Common Joe on Sunday May 11 2014, @10:29AM
I don't know. I don't have a brain that can reach PhD levels, so I'm no expert, but this whole thing smells a little overblown or fishy. The articles says they use lasers to hide information with only a few photons. I was ready to call BS but noticed the sentence "That means an eavesdropper (that's "Willie" in the diagram above) would be unable to distinguish the coded message from background noise -- like it never happened." had a link to this article [extremetech.com] from a year ago about temporal cloaks.
Ok... So, the article about hiding information in a laser beam makes a little more sense... except I'm dubious about temporal cloaks from the get-go. It sounds too good to be true. Like the perpetual motion machine. The claim that it is impossible to break the code is too overhyped for my taste. After all, some people thought the enigma machine was unbreakable too.
I could be very wrong and this could be bullet proof encryption, but I don't understand the technology well enough about temporal cloaks. To me, it sounds like the message could be reconstructed if the key were ever found out. And how does one hide a laser with that kind of technology anyway? Can anyone else speak a bit more about spacial and temporal cloaks?
(Score: 2) by JoeMerchant on Sunday May 11 2014, @11:57AM
Some kit is required at both the sending and receiving end, so, possession of this kit is indication that a message may be sent.
Regardless of encrypted message delivery method, if you constantly chatter, then nobody knows when the encrypted message is saying something like "MARYHADALITTLELAMB" or "TASKAGENT004TOELIMINATETARGETVICTORAT1900", I believe this is the theory behind the short wave "numbers stations" which seem to have defied at least public breaking for decades.
I suppose there's some academic value in all this secret message theory, but, from a practical perspective, hiding messages in everyday communications that don't require exotic gear to decode would seem to be more practical.
🌻🌻 [google.com]
(Score: 0) by Anonymous Coward on Sunday May 11 2014, @01:33PM
i can see it now... "i'm da HaX0r and ima gunna crack your shit up... AHHH MY EYE! I'M BLIND!!!!"
(Score: 3, Interesting) by VLM on Sunday May 11 2014, @12:07PM
Thanks for the arxiv link. Without the journalist filter in the way, I was able to figure out how it works, kinda interesting.
This might not be perfect but the one liner TLDR is something like if you cut down the signal until you end up with just one photon sized signals, then in the event you lose a photon here or there, a fancy enough error correcting code will fix it for you while its not enough to enable an attacker to decode it.
My pitiful attempt at a numerical example, or at least analogy, is if you try to send 100 bits of data, and the absolute best ECC out there turns that into 110 photons of which you can afford to lose no more than 3 photons, and about 99% of photons make it to the correct detector and 1% miss and we'll incredibly optimistically assume all 1% are captured by the enemy (obviously totally made up numbers to make the math easy). Lets run this thing. So sender blasts out his message, and intended recipient only gets 108 or so photons, and his fancy ECC works down to 107 so all is well. The enemy gets a whopping 2 photons. Not sure what he can do with that, can't decode 2 photons into 100 bits because if that were possible we'd already be implementing that modulation scheme, can't even really "prove" communication is happening. The stats are more complicated because obviously every packet doesn't lose precisely 1% of photons, its a smooth graph, and with real numbers instead of made up numbers it actually works out.
Note that they're all talking theoretical cryptographer not military intelligence. If the physicists can't figure out why stereotypical IR communication band photons are occasionally appearing on a mountain top, true, it may never be possible to decode the message even in theory, but those mountain peaks can still get nuked from orbit just to be certain, because a strange long term noise source is still a real world signal even if it can't be decoded. No you can't nuke every random IR photon from orbit, or shouldn't, but if the commo guy says he'd put a commo relay on any or all of those four mountain peaks and only one of the four has stray photons emitted and you've got a spare missile waiting to be used...
(Score: 2) by JoeMerchant on Sunday May 11 2014, @01:23PM
I appreciate theoretical work for its own sake, but this does seem fairly far removed from realistic application. If you are communicating with low number of photon lasers, the comm gear itself is going to be far more telling of potential communications than any stray photons (reflected off passing insects?) Why not simply chatter all the time if you're worried about the enemy knowing "when" you're communicating?
🌻🌻 [google.com]
(Score: 2) by VLM on Sunday May 11 2014, @01:42PM
I originally assumed "of course" it was a DOD grant under some tenuous connection to communicating with submarines or stealth aircraft or drones or maybe special forces deep behind enemy lines, and was motivated enough to check the original paper PDF, and was surprised to discover its just a NSF grant. I sure those guys find this all very interesting, and probably in secret the NSA figured this out in the 70s or whatever, its just now public. Meaning its no longer militarily useful, for some odd reason. Wonder what that is?
Other than DoD stuff the only app I can think of where it might be useful to know someones talking, would be some kind of financial market trading scheme (Well, we "know" he's in a buying mood, but we don't know when, so if we had warning he was about to buy in the immediate future, then we could sneak in our own buy ahead of his, and turn around and sell at a higher price, which is highly illegal front running but legality only matters for the little guys...)
In the paper they generated "a couple" photons by generating a huge boatload of them and attenuating (turning into heat) most of them. But I suppose if you had a commercially scalable way of efficiently directly generating a very small number of photons, then you could save a lot of energy (because its efficient, and you don't need many) while also increasing your security by quite a bit "for free" sorta. Along with ecological analogies to electromagnetic smog and eliminating EMI/EMC interference class of problems. So its got a greenwashing aspect too, not only would saving energy be good greenwashing, it might be more secure and might be more reliable WRT causing interference to other parts of a system.
(Score: 3, Interesting) by JoeMerchant on Sunday May 11 2014, @03:24PM
I always thought the "down a well" effect was a really cool way of attenuating photonic noise / discriminating signal from noise - as an example, transmit a modulated signal with a laser, and on the receiving end, place a 12' long 1/2" diameter pipe with a rough, black painted surface on the inside, in front of your photosensor. Day or night, very few photons that didn't originate from your laser will make it down the pipe to the sensor. I had a house with an attic vent in a gable end wall that I could point such a tube at the top of a tall building, all you'd have to do communicate with that receiver is illuminate the top of that building with your modulated light - probably a laser, but anything that will get photons headed toward my attic would do the trick. Simple, cheap, and bloody effective. Too bad I sold the house before I realized that I didn't even need to place a mirror on the tall building's roof. A wavelength discriminator (colored plastic) lens on the front of the tube would make an even stronger signal/noise ratio.
🌻🌻 [google.com]
(Score: 1, Insightful) by Anonymous Coward on Sunday May 11 2014, @03:17PM
This. Encryption as we currently understand it is Good Enough to keep messages secret for long enough to be useful to the senders and frustrating to adversaries. The battle isn't on the encryption front now. What matters are side channels and obviousness: if you have special laser equipment, you're obvious, and you're a target. If your adversaries want to figure out what you're saying, they'll find a side channel, like inserting a tap into the USB cable [nytimes.com] that connects your computer to your fancy laser-schmaser. If not, they'll just call in an airstrike on your laser, which is helpfully painting you as a target.
(Score: 0) by Anonymous Coward on Sunday May 11 2014, @04:01PM
"First Covert Communication with Lasers"
What did the lasers have to say, covertly?
(Score: 2) by hash14 on Sunday May 11 2014, @04:46PM
As computing power continues to increase, previously unbreakable forms of encryption have crumbled.
It's just a big turn-off to read scientific articles which start out with rubbish statements like this. While it is true, often these encryption systems are poorly designed, vulnerable, etc. while well-designed ones have remained unbreakable for quite some time.
It just makes the researchers sound desperate for attention (ie. grant money).
This code would have to be shared with the intended recipient ahead of time, which is perhaps the most notable flaw with the whole scheme.
This is why we have asymmetric encryption methods (RSA and the like). Quantum Key Distribution [wikipedia.org] for example, ensures that any information that you send was not snooped on by an eavesdropper. So it's not really a shortcoming for this method - any encrypted communication over a network works nowadays starts with an asymmetric encryption scheme to negotiate the exchange of a symmetric key. That could change of course with future developments, but for now it's the standard.
(Score: 2) by Foobar Bazbot on Sunday May 11 2014, @04:53PM
No, pulse position modulation works exactly as I'd expect, and I'm not sure I've ever heard of it before (though it probably popped up in some list in a textbook). If you know what PWM, PFM, PCM, and PDM are, it's not hard to figure out PPM.
I think most of the SN community would get it from the name, but if you want to include an explanation for those who don't, great! But we don't need the introduction that presumes to tell us how stupid we are.
(Score: 1) by tftp on Sunday May 11 2014, @07:58PM
No, pulse position modulation works exactly as I'd expect, and I'm not sure I've ever heard of it before
Some UHF radio relay stations used pulse position modulation in concentrators. They were designed somewhere in 1960's. It's trivial to implement with just analog circuits. Something like this [russianarms.mybb.ru].
(Score: 2) by AnonTechie on Tuesday May 13 2014, @01:16PM
What the Most Secure Email in the Universe Would Look Like:
Say you wanted to send an email more secure than any message that had ever been transmitted in human history, a message with absolutely no chance of being intercepted. How would you do it?
http://www.defenseone.com/technology/2014/05/what- most-secure-email-universe-would-look/84247/ [defenseone.com]
Albert Einstein - "Only two things are infinite, the universe and human stupidity, and I'm not sure about the former."