Sending secret messages over public internet lines can take place with new technique

Eurekalert ^ | 10-Oct-2006 | Colleen Morrison

[NY Attitude]

What tower?

[familyop]

"This is old stuff. For instance, properly trained observers can detect the tower in this picture:"

Hmmm...for some of us, finding the tower is as difficult as trying to figure Skanamaru out.

The inside of old Toshiba COCOM Affair (Troll reads a book)
http://209.157.64.201/focus/f-bloggers/1634861/posts

[Mark Felton]

is this "spread spectrum"?

[pepsi_junkie]

In short, only works in the lab.

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.

[nevergiveup]

YAWWWWWN!

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.

[mkjessup]

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? ;

[nevergiveup]

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

I used truly random noise and a little hardware. No software or careful filtering needed.

[tracer]

Thanks for the trip down Mammary Lane....

[theDentist]

You think all messages into America from S.A., Jordan, Syria, and Iran are by word of mouth?

[pepsi_junkie]

I used truly random noise

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.

[pepsi_junkie]

Wasting massive amounts of bandwidth.

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.

[taxcontrol]

The only problem is that in my experience in building DWDM networks, most optical filters are hardware based and designed to perform only one or two functions. Either they filter as a straight db filter (an attempt to eliminate the noise level) or they are "frequency" filters (only allowing a specific chromatic range through... or both. From my read on the article, it would appear that either type of filter is very likely to inhibit the proper operation of the optical network. Further, in optical repeating devices or devices that provide the translation from optical to electrical and then regen the signal out the optical interface, would also require special changes to allow for these signals to pass.

But... I have not tested this at all so it might work. But the disclaimer about the filters would have me on the pessimistic side.

[ASA Vet]

Interesting discussion
by folks wishing they were able to do this.
of one secret writing method.
Reading between the lines in white doesn't add a bit of protection from us though.

[ASA Vet]

Maybe we can ask if she could give directions to the nearest bar?

[Redbob]

Tower?
What "Tower?"

Have you got another test that I could try?

[Redbob]

Tower?
What "Tower?"

Have you got another test I could try?
This one is too hard.

[Alia]

=Marking article=

[Redbob]

Dang Verizon wireless connection!

[nevergiveup]

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.

[arthurus]

Could she even stand up without her hand on that tree?