Maybe we can ask if she could give directions to the nearest bar?
Posted on 10/10/2006 11:15:52 AM PDT by Teflonic
WASHINGTON, Oct. 10 -- A new technique sends secret messages under other people's noses so cleverly that it would impress James Bond--yet the procedure is so firmly rooted in the real world that it can be instantly used with existing equipment and infrastructure. At this week's annual meeting of the Optical Society of America in Rochester, N.Y., Bernard Wu and Evgenii Narimanov of Princeton University will present a method for transmitting secret messages over existing public fiber-optic networks, such as those operated by Internet service providers. This technique could immediately allow inexpensive, widespread, and secure transmission of confidential and sensitive data by governments and businesses.
Wu and Narimanov's technique is not the usual form of encryption, in which computer software scrambles a message. Instead, it's a more hardware-oriented form of encryption--it uses the real-world properties of an optical-fiber network to cloak a message. The sender transmits an optical signal that is so faint that it is very hard to detect, let alone decode.
The method takes advantage of the fact that real-world fiber-optics systems inevitably have low levels of "noise," random jitters in the light waves that transmit information through the network. The new technique hides the secret message in this optical noise.
In the technique, the sender first translates the secret message into an ultrashort pulse of light. Then, a commercially available optical device (called an optical CDMA encoder) spreads the intense, short pulse into a long, faint stream of optical data, so that the optical message is fainter than the noisy jitters in the fiber-optic network. The intended recipient decodes the message by employing information on how the secret message was originally spread out and using an optical device to compress the message back to its original state. The method is very secure: even if eavesdroppers knew a secret transmission was taking place, any slight imperfection in their knowledge of how the secret signal was spread out would make it too hard to pick out amidst the more intense public signal.
Although the researchers have made public this transmission scheme, and the components for carrying it out are all available, lead author Bernard Wu does not think this technique is being used yet.
"As the method uses optical CDMA technology, which is still undergoing significant research, I don't think any government or corporation is implementing this technique yet," Wu says.
While Wu foresees that government and businesses would have the greatest use for this technique, consumer applications are possible, he says. For example, consumers may occasionally transmit sensitive data via fiber-optic lines for a banking transaction. "This would not be a primary transmission scheme one would employ 24/7, as the price for enhanced security is a lower transmission rate," says Wu. Yet, since consumers send encrypted information to banks only intermittently, "the stealth method is practical" for that purpose, he says.
What tower?
is this "spread spectrum"?
No, I dont get that read. You need a form of matched filter but that's software. You use a pseudo random code to encode the signal and at the other end a matched filter (can be hardware or just software depending of the speed/bandwidth needs) which is properly seeded with the same pseudo random code sequence can pluck out the correct signal componenets from where they were buried. This is done all the time with spread spectrum radios, radars, etc. I admit I havent read the paper but from the article description this sounds like basic spread spectrum technology applied to a fiber optic channel. Different noise characteristics than the atmosphere, which is probably why this is considered novel, but the technique is well established and in use all over.
Interestingly, Spread Spectrum was first patented by Hedy Lamarr (the actress!) in the early 1940s.
I built an equivalent system 20 years ago that used LEDs. I demonstrated it to several appropropriate potential customers but for a variety of reasons (some valid), it never got past the "interesting but..." stage.
Wasting massive amounts of bandwidth.
Is this a great country or what?
I know that nice clean looking wholesome HEALTHY gal just HAS to vote Conservative, right? ;
I used truly random noise and a little hardware. No software or careful filtering needed.
Thanks for the trip down Mammary Lane....
You think all messages into America from S.A., Jordan, Syria, and Iran are by word of mouth?
If it's pseudo random, both sides can generate the same sequence and thus stay synchronized. How do you randomly encode the signal (really randomly) and get it back? If it is true random data, by definition it would be impossible for both sender and receiver to have the same sequence. I suppose you could use truly random data to encode a signal for recording as a rudimentary form of encryption as long as you saved the random sequence to later reconstruct (as the key) but I dont know how you could do it in a comms system unless perhaps you use static random data which each side has recorded.
Actually, I think the opposite is true. In radar theory, if you use signals encoded appropriately you can greatly decrease the power you transmit. The reason is that it is a lot easier to extract the signal from the noise in the returns due to what is called the integration imprvement factor which results from the use of a known code in the system. In fact it is so much easier that the signal can be made much smaller and still be found. I would think that in a fiber channel with fixed capacity, the use of smaller signals which utilize this same integration improvement to pull them out would allow much more efficient use of the bandwidth.
Maybe we can ask if she could give directions to the nearest bar?
Tower?
What "Tower?"
Have you got another test that I could try?
Tower?
What "Tower?"
Have you got another test I could try?
This one is too hard.
=Marking article=
Dang Verizon wireless connection!
You didn't say anything wrong but that's not how I did it. Sorry and don't take it personnel, but since it has been so long and since I have already talked all I want to talk about it (to people with $'s) I am of the age that I'd rather concentrate on reply's from IzzyDunne and ASA Vet.
Could she even stand up without her hand on that tree?
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